2018SYSTEMATIC MAPPING REVIEW:

Effects of partial sick leave versus full-time sick leave on sickness absence and work participation

REPORT

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Publishedby

Norwegiantitle

FolkehelseinstituttetOmrådeforhelsetjenesterEffektavgradertsykmeldingvs.fullsykmeldingpåsykefraværogarbeidstilknytning:ensystematiskkartleggingsoversikt

Englishtitle Effectsofpartialsickleaveversusfull‐timesickleaveonsicknessabsenceandworkpar‐ticipation:asystematicmappingreview

Responsible CamillaStoltenberg,directorAuthors

JoseF.Meneses‐Echavez,projectleader,researcherNikita,Baiju,researcherRigmorC.Berg,departmentdirector

ISBN 978‐82‐8082‐917‐7Typeofreport SystematicmappingreviewNo.ofpages 56(77inklusivvedlegg)Comissioner NAV

Subjectheading(MeSH)

Sickleave,returntowork,disabilityevaluation

Citation

Meneses‐EchavezJF,BaijuN,BergRC.Effectsofpartialsickleaveversusfull‐timesickleaveonsicknessabsenceandworkparticipation:asystematicmappingreview.Report−2018.Oslo:Folkehelseinstituttet,2018.

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Content

CONTENT 3

HOVEDBUDSKAP 5

SAMMENDRAG 6

KEYMESSAGES 9

EXECUTIVESUMMARY(ENGLISH) 10

PREFACE 13

ABBREVIATIONS 14

BACKGROUND 15

METHODS 21 Whatisasystematicmappingreview? 21 Selectioncriteria(identifyingtheresearchquestion) 22 Literaturesearch(identifyingrelevantstudies) 23 Studyselection 24 Dataextraction(chartingthedata) 24 Qualityappraisaloftheincludedstudies 24 Collatingandsummarizingtheresults 25 RESULTS 26 Searchresults 26 Descriptionofincludedstudies 27 Qualityappraisaloftheincludedstudies 35 Summaryofmainfindingsfromtheincludedstudies 35 DISCUSSION 45 Mainfindings 45 Generalizabilityandstrengthoffindings 46 Comparisonwithotherreviews 48 Strengthsandweaknesses 48 Implicationsforpractice 49 CONCLUSION 50

REFERENCES 51

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APPENDIX 57 Appendix1.Glossary 57 Appendix2.Searchstrategies 58 Appendix3.Excludedstudies 61 Appendix4.Adjustedanalysesandcovariatesintheregistry‐basedstudies 62 Appendix5.Definitionofthestatisticalanalysesintheregistry‐basedstudies 73 Appendix6.Qualityappraisaloftherandomizedcontrolledtrial 75 Appendix7.Qualityappraisaloftheregistry‐basedstudies 76

5 Hovedbudskap

Hovedbudskap

Høytsykefraværblantarbeidstakereerenbekymringimangeland.Gra‐dertsykmeldingerenkombinasjonavarbeidogsykepengersombenyt‐tesnårarbeidstakerenerdelvisarbeidsufør,slikatdenansattekanværefraværendefrajobbendelavtidenogjobbeendelavtiden.Folkehelse‐instituttetfikkioppdragavNAVåutføreenkartleggingavdenempiriskeforskningenomeffektenavgradertsykmeldingversusfullsykmelding.MetodeViutførteensystematiskkartleggingsoversikt.Ijanuar2018gjordevietomfattendelitteratursøk,inkludertsøkistoredatabaser,referanselister,grålitteratur,ogvikontaktetarbeidslivsorganisasjonerogdepartement.Toforskerevurderteuavhengigavhverandrealleidentifisertereferan‐serogdenmetodiskkvalitetentildeinkludertestudiene.Vihentetutdatafradeinkludertestudieneogutførtebeskrivendeanalyser.Synteseavindividuellestudieresultaterinngårikkeiensystematiskkartleg‐gingsoversikt.ResultaterViinkluderteenrandomisertkontrollertstudieog12registerbasertestudier.De13studieneinkluderteca.2,74millionersykmeldte.Studienehaddefølgendekjennetegn: Elleveavstudienevarfranordiskeland,inkludertfirefraNorge. Allestudienehaddeentenmoderatellerhøymetodiskkvalitet. Denrandomisertekontrollertestudieninkludertefinskeansatte

(n=62)somvarsykmeldtpågrunnavmuskel‐ogskjelettplager,mensderegisterbasertestudienehovedsakeliginkluderteansattemedmuskel‐ogskjelettplagerellerpsykiskelidelser.

Detvar15utfall,hvoravhovedutfallenevararbeidsdeltakelse,varighetavsykefravær,arbeidsførhetogsosialestønader.

Funnenetyderpåatgradertsykmeldingerforbundetmedflerepositiveutfall,sliksomhøyerearbeidsdeltakelseogkorteresykefravær,mensikrekonklusjoneromeffekteneavgradertsykmeldingerbegrensetpågrunnavdetstoreflertalletavobservasjonsstudierpådettetemaet.

Tittel: Effekt av gradert sykmelding vs. full sykmelding på sykefravær og arbeidstilknytning: en systematisk kartleggingsoversikt ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Publikasjonstype: Systematisk Kartleggingsoversikt En systematisk karleggingsoversikt kartlegger og kategoriserer eksisterende forskning på et tema og identifiserer forskningshull som kan lede til videre forskning. ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Svarer ikke på alt: - Ingen syntese av resultater - Ingen vurdering av evidensen ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Hvem står bak denne publika-sjonen? Folkehelseinstituttet har gjennomført oppdraget etter forespørsel fra NAV ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Når ble litteratursøket utført? Søk etter studier ble avsluttet januar 2018.

6 Sammendrag

Sammendrag

Bakgrunn

Gittdethøyesykefraværblantarbeidstakereerdetimangelandenprioritetåøkear‐beidsdeltakelsenblantpersoneriarbeidsføralder.Gradertsykmeldingerenkombina‐sjonavarbeidogsykepengersombenyttesnårarbeidstakerenerdelvisarbeidsufør,slikatdenansattekanværefraværendefrajobbendelavtidenogjobbeendelavti‐den.Detforståssometgradertfravær,somgjøratfolkmedredusertarbeidskraftkanjobbedeltidogfortsattbeholdetilknytningentilarbeidsmarkedet.Gradertsykmeldingvarierermellom20%og99%,ogkanmuliggjøreraskerereturtilarbeid.Imangeland,spesieltdenordiskelandene,erdettetiltaketsettsomdetførstealternativetforåtakleøkendesykefraværogforhindreekskluderingfraarbeidsmarkedet.Forskningpågradertsykmeldingharhovedsakeligvistlovenderesultater,spesieltidenordiskelandene.EnnyliguførtevalueringavordningenmedgradertsykmeldingiNorgeidentifiserteimidlertidbarrierernårdetgjelderbrukenavordningen,sliksomomfattendebyråkrati,vanskeligåforstå‐ogtilgjengeligtilgangtilinformasjonsamtmangelpåkvalitetskontroll.Selvomlovenderesultatererpublisertharforskningenomeffektenavgradertsykmeldingblittkritisertavmetodiskegrunner,somforeksem‐pelrisikoforutvalgsskjevhetogsvakhetervedmålingavarbeidsdeltakelse.Peridagfinsdetingensystematiskeanalyseravkunnskapsgrunnlagetforeffekteneavgradertsykmelding.Metode

Vigjennomførteensystematiskkartleggingsoversiktihenholdtilinternasjonalestan‐darder.Ensystematiskkartleggingsoversikt(ogsåkjentsomsystematicscopingreview)erenkunnskapsoppsummeringsomkartleggerogbeskrivereksisterendelitteratur‐ellerforskningsgrunnlagpåetbestemttema.Oppsummeringeninkludereringensyste‐matisksynteseavindividuellestudieresultater(f.eks.ingenmetaanalyse).Viinkludertestudieruansettspråksomevaluerteeffekteneavgradert‐versusfullsykmeldingpåsy‐kefraværogarbeidsdeltakelse.Relevantestudiedesignvarprospektivekontrollertestudiersamtregisterbasertestudier(RB).Prosjektteamet(forskerne)ogoppdragsgive‐ren(NAV)diskuterteogbleenigeomprosjektplanen.Visøkteiåttestorelitteraturdatabaser(frabegynnelseninntil2018),kontakteteksper‐ter,ogsøktewebsidenetilarbeidslivsorganisasjonerogrelevantedepartement,refe‐ranselistenetilalleinkludertestudieroglitteraturoversikterpåtemaet.Toforskerevurderteuavhengigavhverandredeidentifisertereferanseneogdatauthentingenble

7 Sammendrag

dobbeltsjekket.Vigjennomførteuavhengigkvalitetsvurderingavdeinkludertestudi‐enemedbrukavvalidertesjekklister.Vigruppertedatahentetfradeinkludertestudi‐eneihenholdtildereshovedkarakteristika,utførtebeskrivendeanalyserogpresent‐erteresultateneitekstogtabeller.Resultat

Trettenstudier,publisertmellom2010‐2017,møtteinklusjonskriteriene.Allestudienemålteeffekteravgradertsykmeldingsammenlignetmedfullsykmeldingblantvoksnesykmeldte.Viinkluderteenfinskrandomisertkontrollertstudie(RCT)(n=62somvarsykmeldtpågrunnavmuskel‐ogskjelettplager)og12RBer(n=2,742,497somvarsyk‐meldtpågrunnavhovedsakeligmuskel‐ogskjelettplagerellerpsykiskelidelser).Del‐takerneidetolvRBenevarfraNorge,Danmark,Finland,SverigeogTyskland.Detvarulikegraderavgradertsykmeldingistudiene.IdenfinskeRCTenble50%gra‐dertsykmeldinggitttil70%avdesykmeldte,mens30%avdesykmeldtearbeidetkorteretimer3‐4dageriuken.IRBenevar50%denhyppigstbruktegraderingen.RBeneanalysertelandsdekkenderegisterdatapåsykefravær(bådegradert‐ogfullsyk‐melding)mellom2001og2014.MedhensyntilstudienesmetodiskekvalitethaddedeninkluderteRCTenmoderatkvalitet;dethaddeogså11avde12RBenemensenRBhaddehøymetodiskkvalitet.Deterviktigåfremheveatregisterbasertestudiererdår‐ligegnettilåpåvisekausalesammenhenger.SammendragavhovedfunnfradeinkludertestudieneSykefravær:DenfinskeRCTenogtreRBerrapportertepositiveresultateravgradertsykmelding,sammenlignetmedfullsykmelding,påsykefraværvedettårsoppfølging.ArbeidsdeltakelseReturn‐to‐work(RTW):DenfinskeRCTenfantatgradertsykmeldingforbedretar‐beidsdeltakelsensammenlignetmedfullsykmeldingvedettårsoppfølging.AlledeniRBenesommåltearbeidsdeltakelse,bortsettfraennorskRB,vistebedreresultaterblantdemedgradertsykmeldingsammenlignetmedfullsykmelding.Arbeidsledighet:TreRBer–fraNorge,TysklandogFinland–rapportertelaverear‐beidsledighetblantpersonersomhaddeværtpågradertsykmeldingsammenlignetmedpersonersomhaddeværtfulltidssykmeldt.

GradavuførhetogattføringGjentakendesykefravær:DenfinskeRCTenfantingensignifikanteforskjellermellomgruppensomhaddegradertsykmeldingogdesomhaddefullsykmeldingnårdetgjel‐dergjentakendesykefravær.Funksjonsnivå:Ingenforskjellermellomgradert‐ogfullsykmeldingblerapportertidenfinskeRCTenvedettårsoppfølgingogiénRBfraNorge,menstoandreRBer(fraNorgeogFinland)fantatgradertsykmeldingvarforbundetmedbedringerifunksjons‐nivå.

8 Sammendrag

Produktivitetstap:KundenfinskeRCTenrapportertepåutfalletproduktivitetstap.DatafradenneRCTenvisteatdetikkevarsignifikantforskjellpåproduktivitetstapmellomgradert‐ogfullsykmeldingvedettårsoppfølging.Uførepensjon:EnnorskRBvisteatgradertsykmeldingvarforbundetmedenhøyeregradavuførepensjonsammenlignetmedfullsykmelding.DetotyskeRBenerappor‐terteenredusertrisikoforåmottauførepensjonhosansattepågradertsykmelding.EnfinskRBfantatgradertsykmeldingvarforbundetmedlavererisikoforfulluførepen‐sjonsammenlignetmedfullsykmelding,mensmotsattsammenhengblefunnetforri‐sikofordelvisuførepensjon.Sosialestønader:FireRBerfantatgradertsykmeldingvarforbundetmedenlaveregradavsosialestønadersammenlignetmedfullsykmelding.HelserelaterteutfallBaretoavdeinkludertestudienerapportertepåhelserelaterteutfall.DenfinskeRCTenfantingenforskjellermellomgradertogfullsykmeldingpåsmerteintensitet,menvistepositiveresultaterforgradertsykmeldingpåbådeselvrapportertgenerellhelseoghel‐serelatertlivskvalitet.EntyskRBvisteatpersonermedgradertsykmeldingfungertebedrefysiskogfølelsesmessigenndesomhaddefullsykmelding.DenfinskeRCTenfantingenforskjellermellomgradertogfullsykmeldingnårdetgjaldtdesykmeldtesdepresjonssymptomer,mensdentyskeRBenvisteatgradertsykmeldingvarforbundetmedforbedringermedhensyntildepresjon‐ogangstsymptomerogarbeidsevne,sam‐menlignetmedfullsykmelding.Konklusjon

Forskningsgrunnlagetforeffektenavgradertsykmeldingsammenlignetmedfullsyk‐meldingbeståravénRCTog12RBer,medtotaltca2,74millionerpersonersomersyk‐meldtpågrunnavhovedsakeligmuskel‐ogskjelettplagerellermentalelidelser.Deink‐ludertestudienevistesammenfallendemønsteriresultatifavøravgradertsykmelding.BådeRCTenogRBeneindikerteatgradertsykmeldingerforbundetmedkorteresyk‐meldingoghøyerearbeidsdeltakelse.ResultatenefradenfinskeRCTenindikerteatan‐sattemedmuskel‐ogskjelettsykdommerrapportertebedregenerellhelseoglivskvali‐tetmedgradertsykmelding.DenneRCTenfantatgradertsykmeldingikkeharnoenef‐fektpågjentakendesykefravær,produktivitetstapellersmerte.Positivesammen‐hengermellomgradertsykmeldingogforbedringavansattesfunksjonshemmingogdepressivesymptomerblestøttetavRBene,menikkeavRCTen.ResultaterfraRBeneantyderatbrukavgradertsykmeldingerforbundetmedlaveresannsynlighetforåmottabådeuførepensjonogsosialestønader,samtbedreskårepåfysisk‐ogfølelses‐messigfungering,angstogarbeidsevne.SikrekonklusjoneromeffekteneavgradertsykmeldingerbegrensetpågrunnavdetstoreflertalletavRBerpådettetemaet.ObservasjonellestudiersomRBergirenbety‐deligrisikoforsystematiskeskjevheteriresultatenesomgjørdetvanskeligågisikresvarpåspørsmålomårsakogvirkning.FlereRCTeravhøymetodiskkvaliteternød‐vendigforåkunnetrekkeklarekonklusjoner.

9 Keymessages

Keymessages

Inmanycountries,thehighsicknessabsencerateinworkingagepeopleisaconcern.Partialsickleave(PTSL)isareturn‐to‐workstrategythatenablesemployeestobeabsentfromworkpartofthetimeandremainworkingforaproportionofthetime.TheNorwegianLaborandWelfareAdministration(NAV)commissionedtheNorwegianInstituteofPublicHealthtomapallevidenceontheeffectsofPTSLversusfull‐timesickleave(FTSL)onsicknessabsenceandworkparticipation.MethodsWeconductedasystematicmappingreview.InJanuary2018,wecon‐ductedanextensiveliteraturesearch,includingsearchesinmajordata‐bases,referencelists,greyliterature,andwecontactedlaboragenciesandinternationalministries.Twoindependentreviewersscreenedallre‐trievedrecordsandappraisedtheincludedstudies.Weextracteddatafromtheincludedstudiesandperformeddescriptiveanalyses.Synthesisofindividualstudyresultsisnotpartofsystematicmappingreviews.ResultsWeincludedonesmallrandomizedcontrolledtrialand12registry‐basedstudies.The13studiesincludedabout2.74millionemployeesonsickleave.Thestudiesexhibitedthefollowingcharacteristics: ElevenofthestudieswerefromNordiccountries,includingfourfrom

Norway. Allstudieshadeithermoderateorhighmethodologicalquality. TherandomizedcontrolledtrialincludedFinnishemployees(n=62)

whoweresick‐listedduetomusculoskeletaldisorders,whiletheregistry‐basedstudiesmostlyincludedemployeeswitheithermusculoskeletal‐ormentaldisorders.

Therewere15outcomes,ofwhichthemostfrequentlyreportedoutcomeswereworkparticipation,sicknessabsenceduration,disability,andsocialwelfarebenefits.

ThefindingsindicatedthatPTSLmaybeassociatedwithseveralfavora‐bleoutcomessuchasshortersicknessabsenceandhigherworkpartici‐pation.However,firmconclusionsabouttheeffectsofPTSLcannotbedrawnduetotheoverwhelmingmajorityofobservationalstudiesinthisbodyofevidence.

Title: Effects of partial sick leave ver-sus full-time sick leave on sick-ness absence and work partici-pation: a systematic mapping re-view ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Type of publication: Systematic mapping re-view A systematic mapping review maps out and categorizes exist-ing research on a topic, identify-ing research gaps that can guide future research. ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Doesn’t answer everything: No synthesis of the results No recommendations are made ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Publisher: Norwegian Institute of Public Health ‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐‐Updated: Last search for studies: January 2018.

10 Executive summary (English)

Executivesummary(English)

BackgroundInmanycountries,highsicknessabsenceratesmeanthattheneedtoincreaseworkparticipationofworkingagepeopleisacriticalpriority.Partialsickleave(PTSL),alsocalledgradedsickleave,isareturn‐to‐workstrategythatenablesemployeestobeab‐sentfromworkpartofthetimeandremainworkingforaproportionofthetime.Itisunderstoodasagradedleave,whichallowspeoplewithreducedworkabilitytoworkparttimeandstillkeepthelinktothelabormarket.PTSLvariesbetween20%upto99%,andmightfacilitateaprogressivereturntowork.Inmanycountries,especiallytheNordiccountries,thisreturn‐to‐workstrategyhasbeenconsideredthefirstoptiontotackleincreasingsicknessabsenceratesandtopreventlabormarketexclusion.ResearchonPTSLhasshownlargelypromisingresults,especiallyintheNordiccoun‐tries.ArecentevaluationofthePTSLarrangementinNorway,however,highlightedbarrierstoitsuse,suchasbureaucraticredtape,lackofeasytounderstandandaccessinformation,andqualitycontrol.Althoughpromisingresultshavebeenpublished,re‐searchontheeffectsofPTSLhasbeencriticizedonmethodologicalgrounds,suchasriskofselectionbiasandweaknessesinmeasuringworkparticipation.Todate,nosys‐tematicanalysisoftheevidencebaseontheeffectsofPTSLhasbeenundertaken.ObjectiveTheNorwegianLaborandWelfareAdministration(NAV)commissionedtheNorwegianInstituteofPublicHealthtomapallevidenceontheeffectsofpartialsickleave(PLSL)versusfull‐timesickleave(FTSL)onsicknessabsenceandworkparticipation.MethodWeconductedasystematicmappingreviewaccordingtointernationalstandards.Asystematicmappingreview(alsoknownassystematicscopingreview)isareviewthatmapsanddescribestheexistingliteratureorevidencebaseonaparticulartopic.Thereisnosystematicsynthesisofindividualstudyresults(e.g.,nometa‐analysis).Wein‐cludedstudiesinanylanguageevaluatingtheeffectsofPTSLversusFTSLonsicknessabsenceandworkparticipation.Eligiblestudydesignswereprospectivecontrolledstudiesaswellasregistry‐basedstudies(RBs).Theprojectteam(reviewers)andcom‐missioner(NAV)discussedandagreedontheresearchprotocol.Wesearchedeightmajordatabases,frominceptionto2018,contactedexperts,andhandsearchedwebsitesoflabororganizationsandministries,thebibliographiesofallincludedstudies,andliteraturereviewsinthefield.Twoindependentreviewers

11 Executive summary (English)

screenedtheretrievedreferencesanddataextractionwasdouble‐checked.Wecon‐ductedindependentqualityappraisaloftheincludedstudiesbyusingvalidatedcheck‐lists.Wegroupeddataextractedfromtheincludedstudiesaccordingtotheirchiefcharacteristics,performeddescriptiveanalyses,andpresentedtheresultsintextandtables.ResultsThirteenstudies,publishedbetween2010‐2017,metourinclusioncriteria.Allevalu‐atedtheeffectsofPTSLcomparedtoFTSLinsick‐listedemployees.WeincludedoneFinnishrandomizedcontrolledtrial(RCT)(n=62sick‐listedemployeesduetomusculo‐skeletaldisorders),and12RBs(n=2,742,497sick‐listedemployeesduetomainlymus‐culoskeletal‐ormentaldisorders).Theparticipantsinthe12RBswerefromNorway,Denmark,Finland,Sweden,andGermany.DifferentgradesofPTSLwereobservedacrossthestudies.IntheFinnishRCT,a50%PTSLwasgivento70%ofallsick‐listedemployees,whereas30%ofemployeesworkedshorterhourson3–4daysperweek.IntheRBs,themostcommonlyusedPTSLwas50%.TheRBsanalyzednationwideregistrydataonsicknessabsences(bothPTSLandFTSL)grantedbetween2001and2014,whichindicateda13‐years’timeline.Regard‐ingthestudies’methodologicalquality,theincludedRCThadmoderatequality,asdid11ofthe12RBswhileoneRBhadhighmethodologicalquality.ItisimportanttonotethatRBsdonotenableresearcherstoestablishcausalrelationshipsbetweenaninter‐ventionorexposureandoutcomes.SummaryofmainfindingsfromtheincludedstudiesSicknessabsence:TheFinnishRCTandthreeRBsreportedpositiveresultsofPTSLcom‐paredtoFTSLonsicknessabsenceatone‐yearfollow‐up.Workparticipation:Return‐to‐work:TheFinnishRCTfoundthatPTSLimprovedworkparticipationcom‐paredtoFTSLattheendoftheone‐yearfollow‐upperiod.AllofthenineRBsthatmeasuredworkparticipation,exceptoneNorwegianRB,showedfavorableassociationsinemployeesonPTSLcomparedtoFTSL.Unemployment:ThreeRBs–fromNorway,GermanyandFinland–reportedfavorableeffectsofPTSLcomparedtoFTSLonemployees’unemployment.Degreeofdisabilityandrehabilitationbenefits:Recurrenceofsickleaveforanycause:TheFinnishRCTfoundnosignificantdiffer‐encesbetweenPTSLandFTSLintherecurrenceofsickleaveforanycause.Disability:NodifferencesbetweenPTSLandFTSLwerereportedbytheFinnishRCTatone‐yearfollow‐upandinoneNorwegianRB,whereastwootherRBs(fromNorwayandFinland)foundthatPTSLwasassociatedwithimprovementsonemployees’disa‐bility.

12 Executive summary (English)

Productivityloss:OnlytheFinnishRCTreportedonproductivityloss.DatafromthisRCTshowedtherewasnosignificantdifferenceonproductivitylossbetweenPTSLandFTSLuptoone‐yearfollow‐up.Disabilitypension:OneNorwegianRBreportedthatPTSLwasassociatedwithahigherrateofreceivingdisabilitypensioncomparedtoFTSL,whereasthetwoGermanRBsre‐portedadecreasedriskofreceivingdisabilitypensioninemployeesonPTSL.AFinnishRBfoundthatPTSLwasassociatedwithalowerriskoffulldisabilitypensioncomparedtoFTSL,whereastheoppositeassociationwasfoundfortheriskofpartialdisabilitypension.Allowanceofsocialwelfarebenefits:FourRBsobservedthatPTSLwasassociatedwithalowerallowanceofsocialwelfarebenefitscomparedtoFTSL.Health‐relatedoutcomesOnlytwooftheincludedstudiesreportedonhealth‐relatedoutcomes.TheFinnishRCTfoundnodifferencesbetweenPTSLandFTSLonpainintensity,butshowedpositiveresultsforPTSLonbothself‐ratedgeneralhealthandhealth‐relatedqualityoflife.AGermanRBshowedthatPTSLwasassociatedwithbetterphysicalandemotionalfunctioninginsick‐listedemployees.TheFinnishRCTfoundnodifferencebetweenPTSLandFTSLonsick‐listedemployees’depressivesymptoms,whiletheGer‐manRBshowedthatPTSLwasassociatedwithimprovementsonbothdepressionandanxietysymptoms,andworkingability,whencomparedtoFTSL.ConclusionTheevidenceontheeffectsofPTSLcomparedtoFTSLconsistsofonesmallRCTand12RBs,withatotalofabout2.74millionstudyparticipantswithmostlymusculoskeletal‐ormentaldisorders.ThefindingsindicatePTSLmaybeassociatedwithseveralfavora‐bleoutcomes,suchashigherworkparticipation,butduetotheoverwhelmingmajorityofobservationalstudiesinthisbodyofevidence,firmconclusionsabouttheeffectsofPTSLcannotbedrawn.BothstudydesignssuggestedPTSLmaybeassociatedwithshortersicknessabsencedurationandhigherworkparticipation.TheFinnishRCTre‐portedthatemployeeswithPTSLexperiencedbettergeneralhealthandqualityoflifecomparedtothoseonFTSL.However,itdidnotfindstatisticaldifferencesbetweenPTSLandFTSLonsickleaverecurrence,employees’productivityloss,andpain.TheRBsindicatedalowerprobabilityforpeopleonPTSLofreceivingbothdisabilitypen‐sionandallowancebenefits,disability,aswellasbetterscoresonphysical‐andemo‐tionalfunctioning,anxiety,depression,andworkingability.FirmconclusionsabouttheeffectsofPTSLareconstrainedduetotheoverwhelmingmajorityofRBsinthisbodyofevidence.Observationaldesignshaveconsiderableriskofsystematicdifferencesintheresults,whichmakeitdifficulttoanswerquestionsaboutcauseandeffect.FurtherhighqualityRCTsarenecessaryinordertodrawfirmconclusions.

13 Preface

Preface

TheNorwegianLaborandWelfareAdministration(inNorwegian:Arbeids‐ogvelferdsetaten,NAV)commissionedtheNorwegianInstituteofPublicHealth(NIPH)tomapoutallevidenceontheeffectsofpartialsickleavecomparedtofull‐timesickleaveonsicknessabsenceandworkparticipation.ThecommissionispartoftheongoingframeworkagreementbetweenNIPHandNAV.ThissystematicmappingreviewcanhelptoinformandsupportNAV,otherauthoritiesaswellasotherresearchorganizationsinevidence‐informeddeliberationsabouttheuseofpartialsickleaveforsick‐listedemployees.TheDivisionforhealthserviceswithintheNorwegianInstituteofPublicHealthfollowsastandardapproachinconductingsystematicmappingreviews,whichisdescribedintheNIPHhandbookSlikoppsummererviforskning.Wemayusestandardformulationswhenwedescribethemethods,resultsanddiscussionofthefindings.Contributorstotheproject:

Projectcoordinator:JoseMeneses‐Echavez,researcher,NIPH Othercontributors:RigmorCBerg,Departmentdirector;NikitaBaiju,researcher,

andresearchlibrarianElisabetHafstad,allfromNIPH.Declaredconflictsofinterest:Allauthorsfilledoutaformtodocumentpotentialconflictsofinterest.Noconflictsofinterestweredeclared.TheauthorswouldliketothankElisabetHafstad,researchlibrarianatNIPH,forhelpwithdevelopingthesearchstrategyandforrunningthesearchesinthemajordata‐bases,aswellasHeidNøklebyandDorisToveKristoffersen,bothseniorresearcherswiththeNIPH,fortheirassistancewithcheckingdataaccuracyandguidanceonstatis‐ticalanalysesintheprimarystudies.Wearegratefulforexpertpeerreviewbyprofes‐sorsArneMastekaasa,UniversityofOslo,andPiaSvedberg,KarolinskaInstitute.NIPHisresponsibleforthecontentsofthereviewpresentedinthisreport.Thecom‐missionerofthereviewandpeerreviewersbearnoresponsibility.

KåreBirgerHagenResearchdirector

RigmorCBergDepartmentdirector

JoseF.Meneses‐EchavezProjectleader

14 Abbreviations

Abbreviations

CBA,Controlledbefore‐afterstudyCI,ConfidenceintervalCochraneEPOCgroup,TheEffectivePracticeandOrganisationofCareGroupFRW,Fasterreturn‐to‐workFTSL,Full‐timesickleaveGNI,GrossnationalincomeGP,GeneralpractitionerHR,HazardratioIA‐avtalen,InkluderendearbeidslivavtalenITS,InterruptedtimeseriesMD,MentaldisorderMSD,MusculoskeletaldisorderNAV,theNorwegianLaborandWelfareAdministrationNIPH,NorwegianInstituteofPublicHealthNRCT,Non‐randomizedcontrolledstudy/Quasi‐randomizedstudyOECD,OrganisationforEconomicCo‐operationandDevelopmentOR,OddsratioPICO,Population,Intervention,Comparison,OutcomePRISMA‐ScR,PreferredReportingItemsforSystematicreviewsandMeta‐Analysesex‐tensionforScopingReviewsPTSL,Part‐timesickleaveRB,Registry‐basedstudyRCT,RandomizedcontrolledtrialRR,RiskratioRTW,Return‐to‐workSINTEF,StiftelsenforindustriellogtekniskforskningSLS,SemiparametricLeastSquaresanalysis

15 Background

Background

Sicknessabsenceandtheneedtoincreaseworkparticipationinworkingagepeoplearecriticalprioritiesindevelopedcountries(1).Notonlydoesahighsicknessabsenceratehavesubstantialcostimplicationsforemployersandsocialsecuritysystems,sick‐nessabsenceaffectsworkers’well‐being,self‐esteemandlivelihood(2).Long‐termsicknessabsenceratesarehighinmanyOECDcountries(2).Norwayexhibitsacom‐parativelyhighrateofsicknessabsence(3),whichhasremainedalmostunchangedforthepastfiveyears(4;5).ThemostrecentdatapublishedbyStatisticsNorway(inNor‐wegian:Statistisksentralbyrå)indicatethesicknessabsencerateinthecountrywas6.5%adjustedforseasonalandinfluenzavariations(self‐anddoctorcertified)inthe3rdquarterof2017.Thisrateisconsiderablyhigherinfemales(8.3%)thaninmales(4.9%)(6).TheNordiccountrieshavesimilarsocialsecuritysystems,andingeneralterms,theyarerelativelysimilarintheirdataonsicknessabsence.However,comparisonsacrossthesecountriesareconstrainedduetodifferencesintheregistrationmethodsinthenationalregisters.Forexample,Swedendoesnotregistersicknessabsencesbelow15days(7).Overall,however,datafromtheNordicSocialStatisticalCommittee2015indi‐catethatNorwayandSwedenhavehighratesoflong‐termsicknessabsence,whereasshort‐termsicknessabsence(i.e.sicknessabsenceoflessthan8days)ishighinDen‐markandlowinNorway(7).Further,thereportstates“womenhavemoresicknessab‐sencethanmen.Olderemployeeshavemorelong‐termsicknessabsencethanyoungeremployees.Youngeremployeeshavemoreshort‐termsicknessabsencethanolderem‐ployees”(7).Togatherthemostup‐to‐datedataonsicknessabsenceinthefiveNordiccountries,weconsultednationalministriesandrelevantorganizations(table1).Briefly,Norwayex‐hibitsthehighestrateofsicknessabsenceintheregion.NorwayandDenmarkpaythehighestpercentageofsalarytotheirsick‐listedemployees(percentageofsicknessben‐efitcomparedtosalary),withthelowestpaymentbeingobservedinFinland.Thehigh‐estnumberofdaysawayfromworkbeforeamedicalcertificatemustbepresentedisseeninSwedenandFinland;whereasDenmarkandIcelandshowthehighestnumberofdaysinwhichtheemployerisresponsibleforpayingsicknessbenefits.

16 Background

Table1.DataonsicknessabsenceacrosstheNordiccountriesSickleavedata Norway Denmark1 Finland3 Iceland4 Sweden5

Sicknessabsence 6.5%inthe3rdquarterof2017

3.7%in2014‐2015

Ca5%in2015 1‐2%in2006 2.9%inthe3rdquarterof2017

Numberofdaysawayfromworkbeforeamedicalcertificatemustbepresented

3days 2days 0‐7days

3days 7days

Forhowlongcantheemployeebeoffsickbeforelosingsick‐ness‐benefits?

260days(52weeks)

22weekswithin9months.Bene‐fitscanbepaidforalongerpe‐riodifthere‐cipientfulfilstheprolonga‐tioncondi‐tions1

300days(ex‐cludingSun‐days)overa2‐yearperiod(forthesameillness).120daysforpartialsickness(ex‐cludingSun‐days)overa2‐yearperiod2.

52weeksovera2‐yearpe‐riod.Foreachmonthworked,anemployeeisentitledtowagesfortwodaysofsickleave.Thegen‐eralruleisthatthesickleaverightsofem‐ployeesin‐creasethelongertheyworkforthesameem‐ployee.

From1Febru‐ary2016,thetimelimitwasabolishedinthesicknessbenefitsystem.Hence,thereisnolongeramaximumtimeforhowlonganemployeecanbeoffsick.

Percentageofsick‐nessbenefitcom‐paredtosalary

100% 90‐100%Sicknesscashbenefit(syged‐agpenge)cal‐culatedbasedonthehourlywageoftheemployee,withamaximumofDKK4,245(€571)perweekorDKK114.73(€15.43)perhour(37hoursperweek),andonthenumberofhoursofwork2

Ca70%

Asetfigureir‐respectiveofsalary.Today,governmentpaysIKR1746perday,plusIKR480pereachchildsup‐portedbythepersonreceiv‐ingthebenefits(theamountisdecidedbyministryregu‐lation).

Ca80%

Numberofdaysbe‐forebenefitstartsbeingpaid

None None None None 1

Numberofdaystheemployerisrespon‐sibleforpayingsick‐nessbenefit

16days 30days2 10workingdays(includingSaturdays)

1month 14days

1. DanishdataprovidedbytheDanishAgencyforLaborMarketandRecruitment(STAR)viaemailcommunication(12/02/18).

2. DatafromMISSOC,the“MutualInformationSystemonSocialProtection”.3. FinnishdataconfirmedbyEiraViikari‐Junturaandcolleaguesviaemailcommunication(07/03/18).4. IcelandicdatawerepartiallyconfirmedbytheIcelandicHealthInsuranceviaemailcommunication(15/03/18).5. SwedishdataconfirmedbytheMinistryofHealthandSocialAffairsviaemailcommunication(12/02/18).InNorway,employeesareentitledtosicknessbenefitsfromdayoneiftheyhavebeeninpaidworkforthelastfourweeksbeforethesicknesscasestarts(8).Theemployeris

17 Background

responsibleforpayingthefirst16daysofleave,andthereafterNAVassumesthepay‐ments.Theemployerdesignsafollow‐upplanwithinthefirst4weeks,andameetingwiththesick‐listedemployee,NAV,andthegeneralpractitioner(GP)isarrangedtodis‐cusssolutionsforreturntowork,ensuredialogueandupdatethefollow‐upplan.Asimilarmeetingisalsoorganizedat26weeksofsickleave.Afteroneyearonsickleave,theemployeemaybegrantedatransitionbenefitforuptofouryears(8;9).AlthoughtheapproachestoreducesicknessabsenceintheNordiccountriesvaryduetostructuraldifferencesandvariationsinsicknesspolicies,thecountriesarerelativelycomparablewithregardtotheirpoliciesrelatedtoitandmeasurestoreducesicknessabsence,ascomparedtomanyothercountries,usinginitiativesthatarebasedonclosefollow‐upofthesick‐listedperson.However,alackofevidenceregardingtheeffectsofthosemeasureshasbeenreportedintheliterature(10;11).SomeoftheNordicmeasurestoreducesicknessabsenceanddisabilitypensionincludethefollowing:re‐turntoworkprogram(Denmark),chartingofthepossibilitiesofthelong‐termsicklistedemployees’returntowork(Finland),rehabilitationchain(Sweden),andtheuseofpartialsickleave(possibleinallNordiccountries)(7).Partialsickleave(PTSL),alsocalledgradedsickleave,hasbeenconsideredthefirstop‐tiontotackleincreasingsicknessabsenceratesandtopreventlabormarketexclusion,especiallyintheNordiccountries(3).Accordingtoarecentreport(7),PTSLisunder‐stoodasagradedleave,whichallowspeoplewithreducedworkabilitytoworkparttimeandkeepthelinktothelabormarket.Thatis,itenablesemployeestoreturntomodifieddutiesattheworkplace,andmightfacilitateaprogressivereturntowork(7;12).Anunderlyingpremiseistheexpectationthatworking,andstayingconnectedtotheworkplace,initselfwillcontributetoreducedsickleaveduration(13).PTSLvar‐iesbetween20%upto99%,independentoftheproportionofemployment(8).InNor‐way,useofPTSLgainedtractionafterthe2004restructuringofthenationalsickleaveregulations.Inmostcases,wheneveranemployedpersonaskedforsickleave,theGPshouldconsiderPTSLthedefaultoption(13).AsimilarsituationdevelopedinSwedenafteradvicebythenationalgovernmentintheearly2000stoincreaseuseofPTSL.In2016,PTSLrepresentedaround34%ofallsickleavecasesamongwomenand26%ofthecasesamongmen(14).InNorway,theaimtoreduceratesofsickleavethroughimprovedinclusionmecha‐nismssuchasPTSLisanchoredinthecollectiveagreementoninclusiveworkingcondi‐tions(InNorwegian:Inkluderendearbeidsliv,IA‐avtalen).IA‐avtalenisacollaborativeagreementbetweentheNorwegiangovernmentandsocialpartners.Theagreement,firstsignedin2001,hasbeenrenewedseveraltimes,mostrecentlyin2014forthepe‐riod2014–2018(15).Importantly,the2010agreementstatedthefollowingthreemainobjectives:toreducesickleavesothatsicknessabsencewillnotexceed5.6%,toin‐cludemorepeoplewithreducedfunctionalabilitiesintoworkinglife,andtogetpeopletoretirelater(16).Participationintheagreementisvoluntaryforthecompaniesthatmayormaynotchoosetosigntheagreementandbecomeaso‐called‘IA‐company’(7).TheIA‐agreementincludesthefollowingfivemeasures(7;16):

1. IncreaseduseofPTSL

18 Background

2. Changesintheroleofthesickleavecertifier(e.g.,training,feedbackonownpracticesandprofessionalguidanceintheworksurroundingauthorizedsickleave)

3. EnterprisesandbusinessescanbemembersoftheIA‐agreement4. TheFasterReturn‐to‐Work(FRW)scheme5. Changesinthefollow‐upschemesofsick‐listedemployees

Withregardtopointfour,theFasterReturn‐to‐Work(FRW)scheme(InNorwegian:Raskeretilbake)isacollectionofmeasuresthatintendedtopreventunnecessarylong‐termsickleave(7).Theschemeimpliesoffersonindividualfollow‐up,clarificationandwork‐orientedrehabilitation;offerfortreatmentatspecialisthealthservices(purchaseofhealthservices);andlegislativeamendmentstoensurecloserfollow‐upofsickpeo‐ple.Thus,theFRWschemeisbasedontheintentionthatsick‐listedemployeesgetfasterclarification,follow‐upandwork‐orientedrehabilitationthroughNAV.TheDirec‐torateofHealthandtheLaborandWelfareDirectorateareresponsiblefortheimple‐mentationofthescheme(17).Totesttheideathatanassessmentoffunctionalabilitiescouldstrengthenthepatient’sresources,whichinturncouldfacilitateandencourageanearlyreturntotheworkplace,aNorwegianclusterrandomizedcontrolledtrialwasconducted(18).ItevaluatedtheeffectsofteachingGPsaboutstructuredfunctionalas‐sessmentstochangetheirsick‐listingpractice,especiallyinprescribingmorePTSL.ThestudyresultsshowedthattheinterventionGPsprescribedPTSLmoreoften(oddsratio[OR]1.3,p

19 Background

showedimprovementsonworkinglifeinthecountryaftertheIA‐agreement,andcon‐cludedthattheIA‐companiesfulfilledalltheirobligationswithintheagreement,andexhibitedbettercooperation(e.g.,betterassistancefromworkinglifecentersandmorefocusonclosefollow‐upofpersonsonsickleave).Nevertheless,theevaluationfoundnoeffectsonsicknessabsenceamongIA‐companies,andseveralmethodologicaldiffi‐cultieswerediscussed(22).Continuingitsinterestsinreducingsicknessabsenceinthecountry,theNorwegianMinistryofLaborarrangedameetingwithscientistsandexpertsinApril2013inordertodiscussandreviewtheevidenceregardingthedifferentmeasurestheIA‐agreementimplied(16).AttendeeshighlightedthelackofempiricalresearchontheIA‐agreementmeasures,andencouragedfurtherresearchinthearea.Afterreviewingdatafromdif‐ferentregistriesandstudiesderivedfromthem,expertsobservedthatthesicknessab‐senceratesdecreasedintheperiodswhenuseofPTSLincreased.ThedecreasewaspartiallyattributedtoanincreasedpreferenceamongGPstowardsgradedsickleave(16).Inaddition,employeesonlong‐termsickleavelistedwithGPswhooftenusedPTSLexhibitedshortersicknessabsenceandahigherprobabilityofremainingem‐ployedtwoyearslater.Someexplanatorymechanismsdiscussedbytheexpertswerehealthbenefits,reducedriskofexpulsionfromworkandaneffectofPTSLonem‐ployee’sdisciplineandattitudetowork(16).Recentregistry‐basedanalysespublishedbyNAVobservedthatuseofPTSLdoubledintheperiod2002‐2016.Halfofthesick‐nessabsencecasesgrantedin2016weregradedsickleave,withhalfofthemgradedat50%.However,PTSLofbothhigherandlowerlevelsaremorecommonlyusedovertime.AquarterofpeopleonPTSLmoveontofulltimesickleave(FTSL),andtheriskofmovingontoFTSLishighestinthefirstfewweeksofthesicknessabsenceperiod.Moreover,theresearchersfoundthatwhilethedurationofsicknessabsencehasre‐mainedfairlystableovertime,theuseofPTSLoccursearlierthanbeforeinthecourseofthesicknessabsence,withmostofthecasesgradedalreadyfromthefirstdayofab‐sence(13).TherehavebeendebatesontheeffectsoftheincreasedemphasisonPTSL.EmpiricalresearchonPTSLhasshownlargelypromisingresults,especiallyintheNordiccoun‐tries.Forexample,datafromaFinnishnationwideregistry‐basedstudyshowedbenefi‐cialeffectsofPTSLcomparedtoFTSLonreturntoworkandworkparticipation(23).PTSLhasalsobeenassociatedwithincreasedworkretentionanddecreaseduseoffulldisabilitypensioninlong‐termassessmentsinFinland(24).Similarfindingswerere‐portedinatrialamongFinnishworkerswithmusculoskeletaldisorders(MSDs)(25).InNorway,Kannandcolleagues(26),foundadeclineintheproportionofindividualsonsickleavewhentherateofPTSLincreased,aswellasshortersicknessabsencedura‐tion.DatafromanotherNorwegianregistry‐basedstudy(27)indicatedthatsick‐listedemployeeswhowereonPTSLwhentheycompletedawork‐relatedrehabilitationpro‐gramweremorelikelytoreturntoworkcomparedtothosewhowereonFTSLwhentheylefttherehabilitationclinic.InSweden,PTSLwasfoundtobeassociatedwithanearlierreturntoworkinpeoplewithmentaldisorders(MDs)after60daysofFTSL(28),whilstnoeffectofPTSLonearlyreturntoworkwasobservedamongpeoplewithMDsinanotherstudyconductedinDenmark(29).Grasdal(30),whoreviewedahand‐

20 Background

fulofempiricalstudiespublishedpriorto2016,concludedthatoverall,theresultsindi‐catedthatPTSL“contributestoreductioninsicknessabsence.Specifically,gradingseemstocontributetoreducingthesickleaveperiod,butthereisconsiderableuncer‐taintyaboutthesizeofthiseffect”(p.114).Althoughnotablepromisingresultshavebeenpublished,researchontheeffectsofPTSLhasbeencriticizedforhavingweakexternalvalidity,andmethodologicalflaws,suchasselectionbias,highuseofself‐reporteddata,andweaknessesinmeasuringworkparticipation(1;31).Todate,nosystematicanalysisoftheevidencebaseontheeffectsofPTSLcomparedtoFTSLhasbeenundertaken.Therefore,thissystematicmappingreviewaimedtomapallquantitativeevidenceontheeffectsofPTSLversusFTSLonsicknessabsenceandworkparticipation.

21 Methods

Methods

Weconductedasystematicmappingreviewtoanswerthequestion:whatevidenceex‐istsandwhatdoesitsayabouttheeffectsofPTSLversusFTSLonsicknessabsenceandworkparticipation?Theprojectteam(reviewers)andcommissioner(NAV)discussedandagreedontheresearchprotocol,whichisavailableuponrequest.

Whatisasystematicmappingreview?

Systematicmappingreviews(alsoknownassystematicscopingreviews)arereviewsthatmapanddescribetheexistingliteratureorevidencebaseonaparticulartopic(32).Suchliteraturereviewstakestockoftheresearchavailableinaparticularfield.Thistypeofreviewproducesausefulendproductinitsownright,describingtheem‐piricalresearchthathasbeenundertakenwithinaparticularfieldofstudy,butalsoprovidesanoverviewofaresearcharea,highlightingwhereempiricalresearchislo‐catedandwheretherearegaps.Itdoesnotincludeasynthesisofindividualstudyre‐sults(32;33).Inatypologyofreviews,GrantandBooth(34)explainthatsuchreviews“mapoutandcategorizetheexistingresearchonaparticulartopic,identifyingresearchgapsfromwhichtocommissionfurtherreviewsand/orprimarystudies.”ThepresentmappingreviewwasmethodologicallyguidedbyaframeworkproposedbyArkseyandO’Malley(32),aswellasLevacandcolleagues’(35)recommendationsonclarifyingandenhancingeachstageofthereview.Thus,themethodologicalstepswere:

1.Identifyingtheresearchquestion2.Identifyingrelevantstudies3.Selectingstudies4.Chartingthedata5.Collating,summarizingandreportingtheresults6.Optionalconsultation.

Asseenfromthisoutlineofthemethodologicalstepsofsystematicmappingreviews,qualityappraisalisnotadefinedstepwithinsuchreviews(32;33).However,wede‐cidedtoappraisethemethodologicalqualityoftheincludedstudiesuponagreementwiththecommissioner(NAV).Qualityappraisalwasperformedaspartofstep4,chart‐ingthedata.ThissystematicmappingreviewisreportedinaccordancewiththePRISMA‐ScRreportingguideline(36).

22 Methods

Selectioncriteria(identifyingtheresearchquestion)

Theselectioncriteriawerediscussedandagreedwiththecommissioneraheadoftheliteraturesearch.WeincludedquantitativeresearchaddressingtheeffectsofPTSLver‐susFTSLonsicknessabsenceandworkparticipation.Themainstudyinclusioncrite‐rionwasasubstantialemphasisontheeffectofPTSLversusFTSLasthesubjectmatter.TheselectioncriteriawereguidedbythefollowingPICO(population,intervention,comparison,andoutcome)elements:Population:Part‐timeorfull‐timeadultemployees(16‐69yearsold).Weexcludedstudiesofpeoplewhoweredescribedasself‐employed.Intervention:Partialsickleave(PTSL).Followingthe2015reportbytheNordicSocialStatisticalCommittee(7),wedefinedPTSLasgradedleave,thatallowspeoplewithre‐ducedworkabilitytoworkparttime.PTSLvariesbetween20%upto99%(7;12).WepresentanydifferencesintheconceptualizationofPTSLacrosstheincludedstudiesintheresults.Comparison:Full‐timesickleave(FTSL),i.e.,nophysicalpresenceattheworkplace.Outcomes:

Sicknessabsence(extent,duration,andsimilar):man‐dayslostduetoownsick‐nessasapercentageofcontractualman‐days(6).Oneman‐daycorrespondstothelengthintimeofoneworkingdayforapersoninafull‐timeposition(100%position).Workparticipation(extent,beingfired,andsimilar)measuredaspositionpro‐portion(valuesmightrangebetween0to1)(6).Degreeofdisabilityandrehabilitationbenefits:whetherthepersoninques‐tionisonfull‐orPTSL,andtowhatdegree,isindicatedbythedegreeofdisability.Thedegreeofdisabilityisbetween20%and100%,where100%meansfulldisa‐bility.Ifasicknessabsencecaseconsistsofmorethanonemedicalcertificate,re‐searchersmightreporttheaverageofthedegreesofdisabilityforthemedicalcertificatesinquestion(6).Health‐relatedoutcomes:Diseaseseverityanddisability.

Studydesign:Duetothefactthatthiscommissionwastiedtoaneffectivenessques‐tion,weaimedtoincluderandomizedcontrolledtrials(RCTs)aswellasnon‐random‐izedstudieswithacontrolcondition.Weincludednon‐randomizedstudiesbecauseweanticipatedthatfew,ifany,RCTshadbeenconductedinthisfield.Registry‐basedstudies(RBs)(alsoknownaspaneldataanalysis)wereincludedinthisreviewafterroundsofconsultationwiththecommissioner.RBsinvolvethestatisticalanalysisofdatasetsfromregistriescontainingmultipleobservationsovertimeofasamplingunit(37).RBscanbeconductedbypoolingtime‐seriesobservationsacrossavarietyofcross‐sectionalunits,includingindividuals,countries,orcompanies(37;38).

23 Methods

However,thesestudiesdonotenableresearcherstoestablishcausalrelationshipsamonganinterventionorexposureandoutcomes(38).Insum,weconsideredthefollowingstudydesignsforinclusion:

Randomizedcontrolledtrials(RCT) Non‐randomizedcontrolledstudies/Quasi‐randomizedstudies(NRCT) ControlledBefore‐Afterstudies(CBA) InterruptedTimeSeries(ITS)withatleastthreemeasurementpointsbefore

andaftertheintervention Registry‐basedstudies(RBs)

Wefollowedthedefinitionsofnon‐randomizedstudiesproposedbytheEffectivePrac‐ticeandOrganisationofCareCochraneGroup(39)(seeGlossaryinAppendix1).Publicationdate:Studiespublishedbetween1990and2018.Language:WeincludedalllanguagesaslongastherewasanabstractinEnglish.Anystudiesmeetingtheinclusioncriteriaandpublishedinlanguagesnotmasteredbythereviewteam(English,Spanish,Norwegian,Swedish,Danish,German)wouldhavebeentranslatedwithGoogletranslateorbyacolleagueattheNIPH.Context:Studiesconductedinhigh‐incomeeconomies(GNIpercapitaof$12,236ormore)asdefinedbytheWorldBank(Link:https://data‐helpdesk.worldbank.org/knowledgebase/articles/906519‐world‐bank‐country‐and‐lending‐groups).Literaturesearch(identifyingrelevantstudies)

Afterextensivedialoguewiththecommissionertoagreeontheresearchquestionandtheselectioncriteria,aresearchlibrarian(ElisabetHafstad)plannedandexecutedsys‐tematicsearchesinthefollowingdatabases(frominceptiontoJanuary2018):

CochraneLibrary:CENTRAL Embase MEDLINE PsycINFO PubMed SociologicalAbstracts&SocialSciencesAbstracts SveMed+ WebofScience

Thesearchstrategywasadaptedforeachdatabase.Thefinalsearchstrategyispro‐videdinAppendix2.SearchingothersourcesToidentifyadditionalstudies,wehandsearchedthebibliographiesofallincludedstud‐ies,aswellasanyliteraturereviewsandseminalreportsaboutPTSL.Wesearchedthe

24 Methods

websiteoftheNorwegianInstituteofPublicHealth,Idunn(NordicJournalsonline),theNorwegianandNordicindextoperiodicalarticles(Norart),OpenGrey,Google,andGoogleScholarandscreenedthefirst200hits.Tworeviewers(JM,RB)alsohandsearchedontheNordicLabourJournal(http://www.nordiclabourjournal.org/),theCampbellLibraryandthefollowingwebsites:Nordicorganizationsforlaborandworkenvironment

• TheDanishNationalResearchCentrefortheWorkingenvironment• TheDanishAgencyforLaborMarketandRecruitment• FinnishInstituteofOccupationalHealth• TheNorwegianLaborandWelfareAdministration(NAV)• TheNorwegianMinistryofLaborandSocialAffairs• Försäkringskassan(Sweden)• TheSwedishMinistryofHealthandSocialAffairs

Ongoingandrecentlycompletedclinicaltrials

WorldHealthOrganizationInternationalClinicalTrialsRegistryPlatform(http://www.who.int/trialsearch/)

NationalInstituteofHealthclinicaltrialsdatabase(http://clinicaltrials.gov)Studyselection

Allrecordsretrievedthroughtheliteraturesearcheswereindependentlyscreenedforeligibilityagainsttheselectioncriteriabytworesearchers(JMandNB)byusingapre‐designedscreeningform.Wefirstscreenedtitlesandabstractsandthenproceededtofull‐textscreeningofrelevantrecordstodecidefinalinclusionorexclusion.Inclusionwasdecidedbyconsensusandanydiscrepanciesweresolvedbydiscussion.Ifneces‐sary,wewouldhaveinvolvedathirdresearcher(RB)tosolvediscrepancies.Dataextraction(chartingthedata)

Wedesignedadataabstractionformtogatherrelevantinformationfromeachstudy,includingcharacteristicsofstudyparticipants,settings,context,percentageofsickleaveevaluatedinthestudy,comparisons,studydesigns,methods,statisticalanalysesandcovariates,andresults.Onereviewer(JM)extractedalldatafromtheincludedstudiesandasecondreviewer(NB)checkedtheinformationforaccuracyandcom‐pleteness.HNandDTKassistedwithcheckingdataaccuracy.Disagreementsweresolvedbydiscussion,consensus,andparticipationofRB.Qualityappraisaloftheincludedstudies

Tworeviewauthors(JM,NB/RB)appraisedthemethodologicalqualityofeachin‐cludedstudyindependently.Weresolveddisagreementsbyconsensus.Ifnecessary,wewouldhaveinvolvedanotherresearcher.

25 Methods

RCTswereappraisedbyusingtheCochranetoolforassessmentofriskofbiasofRCTs(40).Thus,weassessedthefollowingcriteria:

•Randomsequencegeneration(selectionbias).•Allocationconcealment(selectionbias).•Blinding(performancebiasanddetectionbias),blindingofparticipantsandpersonnelassessedseparatelyfromblindingofoutcomeassessment.•Incompleteoutcomedata(attritionbias).•Selectivereporting(reportingbias).•Otherbias.

WecriticallyappraisedtheRBsbyusingthechecklistforcohortstudiesdescribedintheNIPHhandbook‘Slikoppsummererviforskning’(41).This10‐itemschecklistevalu‐atesknownsourcesofbias,suchasselectionbias,incompleteorlackofreportingofoutcomeassessment,dropouts,confoundingfactors,andblindingofoutcomeassess‐ment.WeusedthistoolbecauseitisthemostsuitableappraisaltoolwecouldidentifyforRBs.Wesearchextensivelyandaskedmethodologicalexperts,andtheirrecommen‐dationwastousethechecklistforcohortstudies.IthasbeenusedbyustoappraiseRBsinprevioussystematicreviews.Whilethischecklisthaslimitations,tothebestofourknowledge,thereisnouniquechecklistforappraisingRBs.Intheeventthatnon‐randomizedcontrolledstudies,includingCBAsandITSs,hadbeenincluded,wewouldhaveappraisedthemethodologicalqualityofsuchstudieswiththetoolsuggestedbytheCochraneEPOCGroup(42).Thistoolincludesadditionalitems(relativetotheCochraneriskofbiastoolforRCTs)toassesstheriskofselectionbiasandsubsequentconfounding.Theadditionalitemsare“werebaselineoutcomemeas‐urementssimilar?”and“werebaselinecharacteristicssimilar?”(42).Collatingandsummarizingtheresults

Asdescribedabove,mappingreviewsprovideanoverview‐anddescriptionofexistingresearch.Datasynthesisislimited,relativetofullsystematicreviews:Asystematicmappingreviewdoesnotincludeasynthesis,suchasmeta‐analysis,ofindividualstudyresults.Inaccordancewiththeaim‐andmethodologicalscopeofsystematicmappingreviews,weanalysedthedatadescriptively,withfrequenciesandpercentages,andpresentedresultsintext,tables,andfigures.Wegroupedstudiesintocategoriesac‐cordingtohowtheywereseentorelatetoeachother,followingadatadrivenap‐proach.Forclarity,wepresentedinformationseparatelyforRCTsandRBsaswellasresearchfromNordiccountries.WenotethatRBsdonotenableresearcherstoestab‐lishcausalrelationshipsamonganinterventionorexposureandoutcomes.

26 Results

Results

Searchresults

Theelectronicsearchesinthemajordatabasesyielded676references,andadditionalsearchesingreyliteraturesourcesadded30references.Atotalof300duplicateswereremoved.Weexcluded380outofthe406referencesscreenedattitle/abstractlevel,andwereadtheremaining26referencesinfull‐text.Thirteenstudiesmetourinclusioncriteria.Threeoutofthe13includedstudieswereidentifiedafterconsultinglaboragenciesandinternationalministries(15;43;44).Figure1depictstheflowdiagramfortheselectionofthestudies.Norelevantongoingstudieswereidentifiedbysearchinginthetrialregistries.Thein‐terventionsunderevaluationintheregisteredprotocolsaboutreturn‐to‐worktrialsin‐cludedbehavioralinterventions,self‐management,psychotherapy,motivationalinter‐viewing,andotherintegratedactivereturn‐to‐workprograms.Excludedstudies

Mostofthe13excludedstudiesreadinfull‐texteitherdidnotevaluatetheeffectsofPTSLorwerenotempiricalresearch.ANorwegianRCTthatevaluatedactivesickleavedidnotmeettheinclusioncriteriaastheauthorsexcludedemployeesonpartialsickleave(45).Thistrialfoundthatactivereturn‐to‐workimprovedneitherthenumberofdaysonsickleavenortheproportionofpatientsreturningtoworkinworkerswithlowbackpainfrom65Norwegianmunicipalities(45).Additionally,twoNorwegianRBswereexcludedbecauseofthelackofacomparisongroupwhowereonFTSL.Thesetwostudiesevaluatedsolelydatafromsick‐listedemployeeswhoreceivedPTSL(26;46).Weprovidethemainreasonsforexclusionofthe13referencesexcludedafterfull‐textconsiderationinAppendix3.

27 Results

Figure1.Flowdiagramoftheselectionofstudies Descriptionofincludedstudies

Theevidencepresentedinthissystematicmappingreviewconsistsof13studies.WeincludedoneRCTfromFinland,reportedintwopublications(25;47),whiletheremain‐ing12studieswereRBs(1;15;17;24;28;43;44;48‐52).Thesestudiesusedobserva‐tionalmethodstoexploretheinteractionsbetweenPTSLanddifferentvariables,suchasreturn‐to‐work(RTW),insetsofpaneldatafromregistries.ResearchaimOverall,all13includedstudiesexaminedtheeffectsofPTSLcomparedtoFTSLforsick‐listedemployees(table2).

References screened at title and abstract (n = 406) 

References identified from the  database searches 

(n = 676) 

Additional references identified from other sources  

(n = 30) 

References after duplicate removal (n = 406) 

References excluded (n = 380) 

References screened in full‐text (n = 26) 

References excluded  (n = 13) 

Included studies  (n = 13) 1 RCT 12 RBs 

28 Results

RandomizedcontrolledtrialResearchersoftheFinnishInstituteofOccupationalHealthconductedtheonlyRCTin‐cludedinthismappingreview.Thetrial,whichfollowedaprospectiveparalleldesignandwasreportedintwodifferentpublications,evaluatedtheeffectsofearlyPTSLonRTWandsicknessabsence(25),andonhealth‐relatedoutcomes(47)amongworkerswithMSDs.Registry‐basedstudiesAllthe12includedRBsevaluatedtheeffectsofPTSLcomparedtoFTSLforsick‐listedemployees.WenotethattwoGermanstudiesevaluatedemployeeswhocompletedarehabilitationprogram,whichismandatoryinthecountry(17;50).Twootherstudies,fromFinland,addressedthetransitiontodisabilitypension(24)andtheintroductionofnewlegislationofPTSL(1).Lastly,oneRB(24)hasacompanionpaperwithanalysesofthesamedataset,whichweappliedwhenrelevant(23).Setting

Ingeneral,itcanbestatedthatmostoftheevidencebaseontheeffectsofPTSLcomesfromNordiccountries,as11studies(85%)weredoneinsuchsettings(1;15;24;25;28;43;44;47‐49;51).ThetworemainingRBswereconductedinGermany(17;50).Seetable2. Table2.Countryandresearchaimoftheincludedstudies(n=13)Study,year Country ResearchaimAndrén2012(48)

Sweden ToexaminethebenefitsofbeingonPTSLcomparedtoFTSLinindividualswithmusculoskeletaldisorders.

Andrén2014(28)

Sweden ToanalyzetheimpactofPTSLontheprobabilityofreturningtoworkwithfullrecoveryoflostworkcapacitywithin1yearforemployeeswithmentaldisorders.

Bethge2016(17)

Germany TodeterminetheeffectsofPTSLondisabilitypensionandreg‐ularemploymentinarandomsampleofrehabilitationpatientswhofinishedarehabilitationprogrambetween2002and2009.

Grødem2015(15)

Norway Tostudyemployeeswhocompletedtheirperiodofsicknessbenefits(2‐3yearsaftercompletion)butarestillunabletofullyreturntowork.

Høgelund2010(52)

Denmark Toexaminetheeffectofanationalgradedreturn‐to‐workpro‐gramontheprobabilityofsick‐listedworkersreturningtoreg‐ularworkinghours.

Kausto2012(24)

Finland ToestimatetheeffectsofPTSLonthe transitiontodisabilitypensionapplyingpropensityscoremethods.

Kausto2014(1) Finland ToexaminetheeffectsofthenewlegislationonPTSLonworkparticipationofemployeeswithlong‐termsicknessabsence.

Lie2014(43) Norway ToevaluatetheeffectsofPTSLvsFTSLonsicknessabsence.Markussen2012(49)

Norway ToexaminewhetherPTSLcanreduceabsenteeismandsubse‐quentsocialinsurancedependency,andpromoteself‐suffi‐ciency.

Nossen2013(44)

Norway ToexploretheroleofdifferentdefinitionsofPTSLcomparedtoFTSLonsicknessabsenceduration.

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Shiri2013(47)Viikari‐Juntura2012(25)RCT

Finland Todeterminethehealth‐relatedeffectsofearlyPTSLamongemployeeswithmusculoskeletaldisorders(47).ToevaluatetheeffectsofearlyPTSLonreturntoworkandsicknessabsenceamongpatientswithmusculoskeletaldisor‐ders(25).

Streibelt2017(50)

Germany TodeterminetheeffectofPTSLinadditiontoamultimodalre‐habilitationprogramonlong‐termworkparticipationinpeoplewithchronicmentaldisorders.

Viikari‐Juntura2017(51)

Finland ToassesstheeffectivenessoftheuseofPTSLattheearlystageofworkdisability(first12weeks)duetomentaldisorderormusculoskeletaldiseaseonsustainedreturntowork(RTW)andoverallworkparticipation.

Typeofpublicationandpublicationyear

Mostofthestudiesincludedinthissystematicmappingreviewwerepublishedinpeer‐reviewedjournals(11studies,85%).TwoNorwegianRBswerepublishedasorganiza‐tionalreports(15;43).TheFinnishRCTwaspublishedin2012‐2013(25;47).TheRBswerepublishedbetween2010and2017,withmostpublishedaround2014.ParticipantsBelow,wepresentthecharacteristicsoftheparticipantsintheRCTandRBsseparately.RandomizedcontrolledtrialTheFinnishtrial(25;47)included62employeesonsickleaveduetoMSDs.Theywererecruitedfromsixoccupationalhealthunitsofmedium‐andlarge‐sizeprivateorpublicenterprises.Theyhadapermanentorlong‐termcontract,workingfull‐time(37‐38hoursperweek),andhadnotbeenonsickleaveduetotheirMSDsfor>2weeksduringtheprecedingmonthand>30daysduringthepreceding3months.Mostofthepartici‐pantsworkedinthehealthcaresectororretailtrade,andaminorityfromcall‐centresormeat‐processingindustry.Aroundhalfoftheparticipantshadhighervocationalschoolbutnoneofthemhadcompleteduniversitystudies(table3).Table3.Characteristicsofparticipants,interventionandcontrolgroupintheFinnishrandomizedcontrolledtrialRandomizedcon‐trolledtrial(RCT)

Population Intervention:Part‐timesickleave,

PTSLN(%)

Comparison:Full‐timesickleave,FTSLN(%)

Viikari‐Juntura2012(25),Shiri2013(47)Finland

N=62employeesAge:meanage44(standarddeviation10)Sex:97%femaleDiagnosis:Musculoskeletaldisorders(e.g.,neckorshoul‐derregion,backorupperorlowerextremities)Ethnicity:notreported

N=31(50%)70%received50%PTSL30%workedshorterhourson3–4daysaweek

N=31(50%)

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Registry‐basedstudiesTheparticipantsinthetwelveregistrystudieswerefromNorway(fourstudies),Den‐mark(onestudy),Finland(threestudies),Sweden(twostudies),andGermany(twostudies).Intotal,2,741,563participantswereanalyzedintheseRBs(range627–1,400,094).Ingeneralterms,thevastmajorityofparticipantsacrosstheRBssharedcommoncharacteristics,suchashavingaregularjobcontract,beingfemale(upto78%)andaround45yearsold(range18‐64).GrødemandcolleaguesincludedNorwe‐gianemployeesolderthan60(15),whileLie(43)andNossenandBrage(44)didnotprovideinformationonparticipants’age,genderordiagnosis.OnlythetwoSwedishstudiesprovideddataonparticipants’ethnicity(28;48).Seetable4.NationalregistriesusedforanalysisAlltwelveRBsuseddatafromnationalregistries.ThefourstudiesconductedinNor‐wayallutilizeddatafromtheNorwegianLaborandWelfareAdministration(NAV),asfollows:

Markussenanalyzeddatafromallsicknessabsencesgrantedfrom2001through2005(49).

NossenandBrageanalyzeddatafromallspellsgrantedin2011(44). Lie(43)analyzeddatafromspellsgrantedto10%ofallpeoplereportedinNAV’sregistryduring2002‐2010.

Grødem(15)analyzeddatafromemployeeswhoterminatedthesicknessbenefitsperiodduringthefirsthalfof2011afteroneyearofsickleave.

ThissuggestssomeoverlapinthecasesbasedontheNAVregistry,betweenLie(43)andMarkussenandcolleagues(49)andbetweenNossenandBrage(44)andGrødemandcolleagues(15).Weprovidefurtherdescriptionsinthesection“partialsickleaveintheincludedstudies”below.Therewerenoindicationsofoverlapbetweendatasourcesintheremainingstudies.Andrénandcollaboratorsusedthesamedatasetfromthe2002sampleoftheSwedishSocialInsuranceAgencycontainingdataofsick‐listedemployeesduetoMSDs(48)andmentaldisorders(MDs)(28).Høgelundandcol‐leaguesuseddatafromthenationalregisterofpaymentsofsicknessbenefitsinDen‐mark,supplementedwithsurveyinformation(52).InthetwoGermanstudies,Bethgeandcolleagues(17)studiedemployeeswhocontinuedonsickleaveaftertheycom‐pletedarehabilitationprogram(January‐June2007),whileStreibeltandcolleagues(50)in2012recruitedemployeeswhohadcompletedarehabilitationprogramandwereeligibleforPTSL.BothstudiesuseddatafromtheGermanPensionInsuranceAgency.Table4.Characteristicsofparticipants,interventionandcontrolgroupsinregistry‐basedstudies(n=12)Registry‐basedstudies

Population Part‐timesickleave,PTSLN(%)

Full‐timesickleave,FTSLN(%)

Andrén2012(48)

N=1170;SwedenAge:20‐64years(50%>46years)Diagnosis:MSDsGender:around60%femaleEthnicity:85%borninSweden

N=140(12%) N=1030(88%)

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Andrén2014(28)

N=627;SwedenAge:20‐64years(50%>46years)Diagnosis:MDsGender:around60%femaleEthnicity:85%borninSweden

N=79(13%) N=548(87%)

Bethge2016(17)

N=3,750;GermanyAge:average45years(range18‐60)Diagnosis:Around63%MSDs.Otherdi‐agnoses:cardiac,oncological,psychoso‐maticGender:around50%femaleEthnicity:notreported

N=1875(50%) N=1875(50%)

Grødem2015(15)

N=17,077;NorwayAge:>60years(bornafter1951)Diagnosis:MSDs(45.5%),MDs(25.4%)Gender:58%femaleEthnicity:notreported

N=5294(31%)>50%PTSL(8.7%)

50%PTSL(14.6%)

50%PTSL,4.2%50%PTSL,2%

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Streibelt2017(50)

N=762;GermanyAge:average47.8yearsDiagnosis:MDs(65%affectivedisorders)Gender:78%femaleEthnicity:notreported

N=381(50%) N=381(50%)

Viikari‐Juntura2017(51)

N=3756;FinlandAge:20‐64(41%20‐44years,37%45‐54years,22%55‐64years)Diagnoses:MDsandMSDsGender:77.5%femalesEthnicity:notreported

N=1878(50%) N=1878(50%)

MSD=Musculoskeletaldisorder,MD=Mentaldisorder,SD=standarddeviationIntervention(partialsickleave=PTSL)

Inthesectionbelow,wepresentthecharacteristicsoftheintervention,PTSL,intheRCTandRBsseparately.RandomizedcontrolledtrialIntheFinnishRCT(25;47),theGPsgavethepatientafitnote,indicatingthedurationofpartialworkdisability,whethercertainphysicalloadsshouldbereduced,andwhetheranyadditionalworkmodificationsweredeemednecessary.A50%PTSLwasgivento70%ofallsick‐listedemployees,whereasduetodifficultiesinarrangingahalfworkday,30%ofemployeesworkedshorterhourson3–4daysaweek.Sometaskmodifica‐tionswerealsoimplementedifnecessary.Registry‐basedstudiesInthe12RBs,alldataontheuseofPTSLweretakenfromthenationalregistriesintherespectivecountries(seeaboveNationalregistriesusedforanalysis).Themostcom‐monlyusedPTSLwas50%,whichwasgrantedinaround70%ofthegradedworkab‐sencesformostofthetime.ThestudyfromDenmarkdescribesPTSLasaworkplacein‐terventionprogramwhereby“sick‐listedworkersreturntotheirpre‐sickleavejobontemporarilyreducedworkinghours”(52).TheRBsanalyzeddataaboutsicknessab‐sences(bothPTSLandFTSL)grantedbetween2001and2014,whichgivesatimelineof13years.Figure2illustratesthedispersionoftheyearsfordataanalysisacrosstheRBs(i.e.,thetimelinefromwhichthedataweretakenintheregistry).ThetwoSwedishRBs,bothwithAndrénasfirstauthor,usedthesameyearsfromtheregistry,butin‐cludedworkerswithdifferentdisorders,MSDsandMDs,respectively(28;48).ItisimportanttohighlightthatallRBs,exceptfortwoNorwegianstudiespublishedbyGrødemandcolleagues(15)andNossenandBrage(44),exploredtheinfluenceofdif‐ferentcovariatesontherelationshipbetweenPTSLandtheoutcomemeasures.MostoftheRBsconductedpropensity‐scorematchinganalysesforbalancingthesamplesontheprobabilityofbeingassignedtoPTSL(sixstudies).ThemostcommoncovariatesusedacrosstheRBsweregender/sexandage(fivestudies),followedbytypeofoccu‐pationanddiagnosis(fourstudies),andgeographicarea,incomeanddataonthephysi‐cianwhograntedthesickleave(threestudies).Othercovariatesincludedthesickleaveduration,previoussickleaves,levelofeducation,etc.DetailsontheadjustedanalysesandthecorrespondingcovariatesacrossRBscanbefoundinAppendix4,anddefini‐tionsofthestatisticalanalysesarepresentedinAppendix5.

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Figure2.Dispersionoftheyearsfordataanalysisacrosstheregistry‐basedstudies(n=12)Comparison

BoththeFinnishRCTandthe12RBsusedFTSLascomparator. Outcomemeasures

Intotal,15outcomeswerereportedinthe13includedstudies.Therewerefourmaintypesofoutcomes:sicknessabsence,workparticipation,degreeofdisability,andhealth‐relatedoutcomes.Workparticipation(RTW)wasthemostcommonoutcome,reportedintenstudies(i.e.,intheRCTandnineRBs),followedbysicknessabsencedu‐ration,disability,disabilitypensionandallowanceofsocialbenefits(eachmeasuredbyfourstudies).Because12ofthe13includedstudieswereRBs,registrydatawerethemostcommonsourceofmeasurement.Table5showsthedifferentoutcomes,numbersofstudiesandtools.Table5.OutcomemeasuresandtoolsintheincludedstudiesOutcomemeasure Numberofstudies ToolsSicknessabsenceduration

1RCT(25)3RBs(44;49;50)

Registrydata

WorkparticipationReturn‐to‐work(RTW)

1RCT(25) Registrydata

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9RBs(1;15;28;43;48‐52)

Unemployment 3RBs(49‐51) RegistrydataDegreeofdisabilityRecurrenceofsickleaveforanycause

1RCT(25)

Registrydata

Disability 1RCT(47)3RBs(15;43;51)

RegistrydataShirietal.2013(47)usedthefollowingtools:OswestryDisa‐bilityIndextoassessthedisabilitylevelduetobackpain;theNeckDisabilityIndextoassesscervicalspine‐relateddisabili‐ties;theQuickDASHtoassessthedisabilitiesofthearm,shoulder,andhand;andtheComprehensiveOsteoarthritisTest(COAT)toassessthesymptomsofthehiporknee.

Productivityloss 1RCT(47) TwoquestionsrecommendedbyBrouweretal.,“Thesubjectswereaskedtoconsiderthelatestfullorpartialworkingdayandcompareittotheirnormalworkdaywhenansweringthequestions:(i)assesstheamountofworkyouwereabletoper‐form,and(ii)assessthequalityofyourwork.Forbothques‐tions,thescalerangedfrom0–10(0=verypoorto10=regularquantityorquality).Incasethereportedvaluewas

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Qualityappraisaloftheincludedstudies

Whilenotarequiredstepinasystematicmappingreview,weassessedthemethodo‐logicalqualityofthe13includedstudies.WeuseddifferentchecklistsfortheRCTandthe12RBs(seemethods).RandomizedcontrolledtrialTheFinnishRCTexhibitedmoderatemethodologicalquality(25;47).Thereweresomeconcernsaboutbothperformanceanddetectionbiasduetothelackofblindingofbothparticipantsandoutcomeassessor.Inaddition,thetrialreportedsomeoutcomesthatwerenotpre‐specifiedintheprotocol.Wefoundnomajorconcernsforselectionorat‐tritionbias.SeeAppendix6foracompletedescriptionofthequalityappraisaloftheRCT.Registry‐basedstudiesWeusedachecklistfromtheNIPHhandbookforsystematicreviews(41)toassesstheoverallqualityoftheRBs,whichresultedinacategorizationofstudiesintolow,moder‐ateorhighmethodologicalquality,asfollows:

Highquality:lowriskofbiasin≥8items. Moderatequality:lowriskofbiasin5‐7items. Lowquality:lowriskofbiasin≤4items.

ElevenoutofthetwelveincludedRBsexhibitedmoderatemethodologicalquality(1;15;17;24;28;43;44;48;49;51;52).Oneshowedhighmethodologicalquality(50).Allstudiesincludedlargenumbersofindividuals,werejudgedasrepresentativeoftheirpopulation,andmeasuredbothexposureandoutcomesequallyandreliably.ThePTSLandFTSLgroupswerecomparableonimportantbackgroundfactorsinfivestudies(1;15;28;50;51).Follow‐uptimewasjudgedasadequateinallstudies.SeeAppendix7foracompletedescriptionofthemethodologicalappraisaloftheRBs.Summaryofmainfindingsfromtheincludedstudies

Weprovideabriefsummaryofthemainfindingsreportedbythestudyauthorsfortheoutcomesincludedinthisreview,i.e.,sicknessabsence,workparticipation,degreeofdisabilityandrehabilitationbenefits,andhealth‐relatedoutcomes.Furtherdatacanberetrievedinthefull‐textpublications.Asummarytable,indicatingdirectionofresultsacrossthestudies,isprovidedattheendofthechapter(table6).Sicknessabsenceduration

TheFinnishRCTofmoderatemethodologicalquality,andthreeRBs,ofmoderateandhighmethodologicalquality,reportedonsicknessabsence.TheFinnishtrialshowedalowerproportionofsicknessabsencedaysinemployeeswithPTSLthaninpeerswithFTSLthroughoutthe12‐monthfollow‐upperiod(20%loweronaverage)(25).

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ThreeRBsmeasuredsicknessabsenceduration.TheNorwegianRBpublishedbyMarkussenandcolleagues(49)foundthatPTSLpredictedreductionsinsicknessab‐sencedurationbymorethan60daysaftercontrollingforpatient/jobcovariatesandphysiciancharacteristics,comparedtoFTSL.Thisreductionincreasedupto74dayswhenspellsexceeding12weekswereanalyzed.AnotherNorwegianstudy,byNossenandBrage(44),observedthattheuseofPTSLinspellslastingatleast15daysandthatwereonFTSLduringthefirst14daysledtoa21daysshortersicknessabsencedura‐tioncomparedtotheuseofFTSL.LargerreductionsinfavorofPTSLwereseenafter8weeksinspellslastinglongerthan2weeksandgradedduringthefirst2weeks(166daysinPTSLvs199daysinFTSL;meandifference=‐33days).ThisdifferenceinfavorofPTSLincreasedupto39daysat12weeks.Conversely,crudeanalysesrevealedshortersicknessabsencesamongthoseassignedtoFTSLcomparedtothoseinPTSL(115daysinPTSLvs23daysinFTSL;meandifference=92days).Thisdifferencewasreducedto13dayswhendataforspellsgradedafter2weekswereanalyzed1.Theanal‐ysisofspellsgradedat

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morethanoneandahalftimesaslikelytoRTWthanthoseonFTSL.Controllingforprevioussicknessabsenceduringthepreceding30daysdecreasedtheHRby11%andcontrollingforbodymassindexdecreaseditby3%.OverallHRforRTW,controllingforage,paininterferencewithsleep,andprevioussicknessabsence,was1.76(95%CI1.21–2.56).ThreeoftheNorwegianRBsreportedonworkparticipation.Grødemandcolleagues(15)reportedthatemployeesonPTSLstayedconnectedtotheirjobsmorethantheirpeersonFTSLattwoyearsafterterminationofthesicknessbenefits(38%inFTSLvs84%in

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sociatedwithagreaterlikelihoodoffullrecoverycomparedtoFTSL(averagetreat‐menteffect0.015)2whenitisassignedinthebeginningofthespell.Andrénalsoob‐servedastrongpositiveeffectofPTSL(averagetreatmenteffect0.387)2,andstatisti‐callysignificant,whenassignedafter60daysofFTSLattheendofthe330daysobser‐vationperiod.DistributionalanalysisoftheeffectparametersshowedthatinagroupofrandomlyselectedemployeesonsickleaveformorethantwoweeksduetoaMD,17.8%ofthemwouldfullyrecovertheirlostworkcapacityifassignedtoPTSLinthebeginningofthespell,butwouldnothavefullyrecoveredtheirlostworkcapacitywith‐outthePTSLtreatment.However,16.3%ofthemwouldnotfullyrecoverifassignedtoPTSL.TheotherthreeRBsthatreportedonworkparticipationwerefromFinland(twostud‐ies)andGermany.InFinland,Kaustoandcolleagues(1)observedreductionsinthelevelofworkparticipationforboththePTSLandtheFTSLgroupsduringtheone‐yearfollow‐up,theabsolutereductionbeinglargerintheFTSLgroup(−26.5%)ascomparedwiththePTSLgroup(−21.2%),whichmeansadifferenceof5.3%(95%CI3.1%to7.5%).Thisdifferenceincreasedupto9.8%(95%CI5.9%to13.7%)inthepropensityscorematchedsubsample(i.e.,theconditionalprobabilityofbeingassignedtoPTSLgivenobservedcovariates).Subgroupanalysesshowedthatinallagecategories,workparticipationdeclinedmoreintheFTSLgroupthaninthePTSLgroup.Thedifferenceinthedeclinewassignificantinagecategories45–54and55–65.Therewasnoeffectinthoseaged35–44.Insubgroupanalyses,astatisticallysignificantlylargereffectinfa‐vorofPTSLwasfoundforpeoplewithmentaldisordersascomparedwiththeotherdi‐agnosticcategories(difference12.8%,95%CI9.0%to16.5%).AnotherFinnishstudypublishedin2017byViikari‐Junturaandcolleagues(51)foundanabsoluteriskdifferenceof8.0%andarelativeriskdifferenceof10.9%infavorofPTSLonsustainedRTW.Inaddition,theauthorsobservedthatthemeanoveralltimespentatworkwas77.4%;itwas10.5%higherinthePTSLgroupcomparedtotheFTSLgroupduringthe2‐yearfollow‐up.SubgroupanalysesshowedthatthedifferencewaslargeramongmenthanwomenandforpeoplewithMDscomparedtoMSDs.InGer‐many,theRBofhighmethodologicalquality,byStreibelt(50),foundthat88.4%ofthePTSLgrouphadreturnedtoworkat15monthsfollow‐upcomparedtoonly72.6%ofthecontrols(RelativeRisk[RR]=1.22,95%CI1.13–1.31).TherelativeriskofreturningtoworkwasgreaterinthePTSLgroupcomparedtoFTSL.ThegreatesteffectofPTSLonRTWwasobservedamongemployeeswhodidnotbelievethattheywouldgobacktoworkafterrehabilitation(74%inPTSLvs49%inFTSL).UnemploymentThreeRBsreportedonunemployment.InNorway,Markussenandcolleagues(49)ob‐servedthatPTSLpredictedariseintheemploymentprobabilitytwoyearsafterthestartofthesickleavebyaround16%(SemiparametricLeastSquares(SLS)estimate0.16,standarderror0.04),aftercontrollingforpatient/jobcovariatesandphysiciancharacteristics.Thisprobabilityincreasedupto20%whenspellsexceeding12weekswereanalyzed.InGermany,Streibelt(50)foundthatsick‐listedemployeesassignedtoPTSLhada60%lowerriskofunemploymentcomparedtopeerswhowereassignedto

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FTSL(RR0.41,95%CI0.26to0.65).Finally,TheFinnishRBpublishedbyViikari‐Jun‐turaandcolleagues(51)observedthatsick‐listedemployeeswhoreceivedPTSLspentlesstimeunemployedduringthe2‐yearfollow‐upcomparedtothosewhoreceivedFTSL.Thedifferenceinproportionswasabout1.8‐fold(3.2%inFTSLvs1.8%inPTSL).Thisdifferencewaslargeramongmenthanwomenandinworkersinmanufacturingcomparedtootherindustries.Insummary,oneRCTfromFinlandandallofthenineRBsthatmeasuredRTW,excepttheNorwegianRBbyLie(43),indicatedpositiveeffectsonRTWforemployeesonPTSLcomparedtoFTSL(15;49‐51).FavorableeffectsofPTSLcomparedtoFTSLonunem‐ploymentwerereportedbyallofthethreeRBsthatmeasuredthisoutcome(49‐51).Degreeofdisabilityandrehabilitationbenefits

Therewerefivetypesofoutcomeswithregardtodegreeofdisabilityandrehabilitationbenefits:recurrenceofsickleaveforanycause,disability,productivityloss,disabilitypension,andallowanceofsocialwelfarebenefits.Wereportthestudyresultsforeachofthesefiveoutcomesseparatelybelow.RecurrenceofsickleaveforanycauseTheFinnishRCT(moderatemethodologicalquality)(25)indicatedthattimetofirstre‐currentsickleavewassimilarinthePTSLandFTSLgroups.However,thenumberofrecurrentsickleavesperpersonyearaftertheinitialsicknessabsenceperiodwasabout20%lowerinthePTSLgroupatone‐yearfollow‐up.DisabilityTheFinnishRCTandthreeRBsreportedondisability.Allhadmoderatemethodologicalquality.NodifferencesbetweenPTSLandFTSLregardingdisabilitywerereportedbytheFinnishRCTatone‐yearfollow‐up(47).ThethreeRBsreportingondisabilitywerefromNorway(twostudies)andFinland.Us‐ingNorwegiandata,Lie(43)foundnostatisticallysignificantdifferencesbetweenPTSLandFTSLonemployees’disabilityaftercontrollingforcovariates(i.e.,age,sex,diagno‐sis,timeinjob,andphysiciandata).Grødemandcolleagues(15)observedthelargestrecoveryamongemployeeswhohad

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4.5‐foldcomparedtotheFTSLgroup(7.9%versus1.8%);theoverallabsoluteriskdif‐ferencewas‐6.1%(95%CI‐7.1to‐4.9)(negativevalueindicatingincreaseinrisk).Higherriskswereseenamongwomen,theoldestemployees,andpeoplewithMSDscomparedwithMDs,andamongpeopleinthepublicsectorandhealthcareandsocialwork.Theseresultsremainedevenafteradjustingforresidualimbalanceinbaselinecovariates(e.g.,age,majorregion,employmentsector,socioeconomicstatus,andan‐nualgrossincome).Insum,oneRCTfromFinland(47)andoneRBfromNorway(43)foundnodifferencesbetweenPTSLandFTSLondisability,whereastwoNordicRBssuggestedpositiveef‐fectsofPTSLonemployees’disability(15;51),exceptwithregardtopartialdisabilityretirementintheFinnishRB(51).ProductivitylossOnlytheFinnishRCTreportedonproductivityloss.DatafromthisRCTofmoderatemethodologicalqualityfoundtherewerenosignificantdifferenceonproductivitylossbetweenPTSLandFTSLuptoone‐yearfollow‐up(regressioncoefficient‐0.6;95%CI‐9.1to7.9;p‐value=0.88).However,thiseffectbecamefavorableforPTSLafteradjust‐ingforbodymassindex,follow‐uptime,timesincebeginningofsymptoms(numberofelapseddays)andthebaselinemeasurebutdidnotreachstatisticalsignificance(re‐gressioncoefficient2.3;95%CI‐4.8to9.5;p‐value=0.52)(47).DisabilitypensionFourRBs,fromNorway,Finland,andGermany(twostudies),reportedondisabilitypension.ThreeoftheRBshadmoderatemethodologicalqualityandonehadhighmethodologicalquality.InNorway,Grødemandcolleagues(15)reportedthatthehigh‐estrateofreceivingdisabilitypensionwasobservedinemployeeswhowereon50%PTSL(12%attheterminationofsicknessbenefits,and19%twoyearslater),whereastheratevariedfrom7%upto13%attheendoftheobservationperiod(January2014)amongemployeeswhowereonFTSL.Thelowestlikelihoodofreceivingadisabilitypensionwasseeninthegroupof

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MDsthaninMSDs.NoassociationswereobservedbetweenPTSLandthetransitiontoanydisabilitypension(partialandfulldisabilitypensioncombined).Lastly,twoGermanRBsexamineddisabilitypension.Bethgeandcolleagues(17)re‐portedthatassigningPTSLtosick‐listedemployeesreducedtheirriskofreceivingadisabilitypensionby40%(HR=0.62,95%CI0.49–0.80)atone‐yearfollow‐up.Streibeltandcolleagues(50)reportedthatPTSLreducedtheriskofreceivingadisabilitypen‐sionby60%(RR=0.40,95%CI0.23‐0.70)comparedtoFTSLat15monthsfollow‐up.Thisstudyhadhighmethodologicalquality.Insum,acrossthefourRBs,theresultsfordisabilitypensionweremixed.TheNorwe‐gianRBsuggestedahigherrateofreceivingdisabilitypensionamongemployeesonPTSLcomparedtoFTSL(15),whereasthetwoGermanRBsreportedadecreasedriskofreceivingadisabilitypensioninemployeesonPTSL(17;50).TheFinnishstudy(24)foundthatPTSLreducedtheriskoffulldisabilitypensioncomparedtoFTSL,whereastheoppositeresultwasfoundforpartialdisabilitypension.AllowanceofsocialwelfarebenefitsFourRBs,fromNorway(threestudies)andGermany,reportedonallowanceofsocialwelfarebenefits.AllfouroftheseRBshadmoderatemethodologicalquality.InaNorwegiansetting,Markussenandcolleagues(49)foundthatPTSLwasassociatedwithfewersocialsecurityclaims(regressioncoefficientadjustedforpatient/jobco‐variatesandphysiciancharacteristics:‐79.7(standarderror11.8))inthe2‐yearperiodfollowingjustaftertheendoftheabsencespell.Thisreductionincreasedupto99daysreceivingbenefitswhenspellsexceeding12weekswereanalyzed.Lie(43)foundthattheprobabilityofreceivingsocialbenefitswasloweramongthoseonPTSLthanFTSL,althoughthedifferencesweresmallandnon‐significant(HRrangedfrom0.95at4weeksto0.80at28weeks)aftercontrollingforcovariates(i.e.,age,sex,diagnosis,timeinjob,anddoctor’sdata).Thesequentialanalysisdidnotrevealdifferencesbetweensecondandthirdsickleaves.Grødemandcolleagues(15)reportedthatallgroups,butnot50%(69%attermination,and40%twoyearsafter),and50%PTSL(59%attermination,and30%twoyearsafter).Theallowanceofsocialbenefitsremainedstableat10%inthe50%PTSL.TheGermanstudy,byBethgeandcolleagues(17),reportedthatemployeeswithPTSLreceivedfewerwelfarebenefitsduetosicknessabsenceandunemploymentuptotheendofthestudyperiodthanthoseinFTSL.Theaccumulatedtimeofreceivingsicknessbenefitswasreducedby52days(95%CI40–64days),short‐termunemploymentben‐efitsby58days(95%CI49–67days),andlong‐termunemploymentbenefitsby15days(95%CI10–20days)atone‐yearfollow‐up.

42 Results

Thus,allfourRBs(15;17;43;49)observedalowerallowanceofsocialwelfarebenefitsinPTSLcomparedtoFTSL.Health‐relatedoutcomes

Onlytwooftheincludedstudiesreportedonhealth‐relatedoutcomes.ThiswastheFinnishRCT(25;47)andaGermanRB(50).TheRCThadmoderatemethodologicalqualityandtheRBhighmethodologicalquality.TheFinnishRCTincludedpeoplewithMSDswhiletheGermanstudyincludedpeoplewithMDs,primarilyaffectivedisorders.Below,wereporttheresultsforthesixhealth‐relatedoutcomesseparately.Thesewere:pain,self‐ratedgeneralhealthandhealth‐relatedqualityoflife,physicalandemotionalfunctioning,depression,anxiety,andworkingability.Pain(intensityandinterferencewithwork)ResultsfromtheFinnishRCT(47)showedreductionsinbothpainintensityandinter‐ferencewithworkinallgroupsduringthefirst8weeksandstabilizedthereafter.NodifferencesbetweenthePTSLandFTSLgroupswereobservedduringa12weeksfol‐low‐upperiodafteradjustingforbodymassindex,follow‐uptime,timesincebeginningofsymptoms(numberofelapseddays)andthebaselinemeasure.Thus,painintensity(≤3months)showedaregressioncoefficientof‐0.4(95%CI‐1.3to0.4;p=0.31);paininterferencewithwork(≤3months)‐0.7(95%CI‐1.6to0.3;p=0.15);paininterferencewithsleep(≤3months)‐0.12(95%CI‐0.9to0.7;p=0.77),andpainat1year‐0.2(95%CI‐0.7to0.4;p=0.48).Self‐ratedgeneralhealthandhealth‐relatedqualityoflifeTheFinnishtrial(47)foundthatemployeeswhoreceivedPTSLself‐reportedbettergeneralhealththanthoseintheFTSLgroup(regressioncoefficient0.5,95%CI‐0.0to1.0;p=0.07),andhigherhealth‐relatedqualityoflifeatone‐yearfollow‐up(regressioncoefficient‐0.5,95%CI‐0.9to‐0.01;p=0.02).Theseanalyseswereadjustedforbodymassindex,follow‐uptime,timesincebeginningofsymptoms(numberofelapseddays)andthebaselinemeasureoftheoutcome.PhysicalandemotionalfunctioningStreibeltandcolleagues’(50)resultsinGermanyshowedthatemployeeswhoreceivedPTSLhadahigherphysical(regressioncoefficient+7.9,p=0.01)andemotional(regres‐sioncoefficient+6.8,p=0.025)rolefunctioncomparedtothoseintheFTSLgroupat15monthsfollow‐up.DepressionNodifferenceswereobservedintheFinnishRCTbetweenthePTSLandFTSLgroupsonsick‐listedemployees’depressionsymptoms(47).Conversely,intheGermanRB(50),peopleinthePTSLgroupdidbetterthanpeopleintheFTSLgroup(regressionco‐efficient−0.6,95%CI−1.1to−0.1;p‐value=0.03)at15monthsfollow‐up.AnxietyDatafromtheGermanRB(50)showedthatpeopleinthePTSLgroupimprovedwithrespecttoanxietysymptoms(measuredwiththesametoolasdepression),compared

43 Results

toFTSL(regressioncoefficient−0.6,95%CI−1.1to−0.1;p‐value=0.03)at15monthsfollow‐up.WorkingabilityTheGermanRB(50)foundthatpeopleinthePTSLgroupdidbetterthanpeopleintheFTSLgroupwithrespecttoworkingability(regressioncoefficient0.1,95%CI‐0.1to0.3;p=0.05)at15monthsfollow‐up,butthedifferencewasnotstatisticallysignificant.Summaryofresultsacrosstheincludedstudies

Table6summarizesthedirectionofresultsacrossthe13includedstudies(15out‐comes).Withregardtocausaleffects,theRCTpresentsthestrongeststudydesignandisthereforehighlighted.However,giventhestudy’ssmallsamplesize(n=62)firmcon‐clusionsabouttheeffectsofPTSLcannotbedrawn.

44 Results

Table6.Summaryofdirectionofresultsacrosstheincludedstudies(n=13)

Legend:+favorstheintervention(partialsickleave,PTSL);‐favorsthecontrolgroup(full‐timesickleave,FTSL);=nodifferencebetweenPTSLandFTSL;*Randomized‐controlledtrial(RCT);#studyofhighmethodologicalquality,remainingstudieshadmoderatemethodologicalquality.Emptycellmeansthestudydidnotexaminetheoutcome.

Outcomemeasure

André

n2012(4

8)

André

n2014(

28)

Bethg

e2016 (1

7)

Grødem

2015 (15

)

Høgel

und2

010 (

52)

Kaust

o2012 (2

4)

Kaust

o2014 (1

)

Lie20

14 (43

)

Marku

ssen2

012 (4

9)

Nosse

n2013 (

44)

Shiri2013(47)*

Viikari‐Juntura2012(25)*

Streib

elt20

17 (50

)#

Viikari‐Jun

tura2

017 (

51)

Sicknessabsence + + + + WorkparticipationReturn‐to‐work + + + + + ‐ + + + +Unemployment + + +DegreeofdisabilityandrehabilitationbenefitsRecurrenceofsickleaveforanycause = Disability + = = +Productivityloss = Disabilitypension + ‐ + + Allowanceofsocialwelfarebenefits + + + + Health‐relatedoutcomesPain(intensityandinterferencewithwork)

= Self‐ratedgeneralhealth + Health‐relatedqualityoflife + Physicalandemotionalfunctioning

+ Depression = + Anxiety + Workingability +

45 Discussion

Discussion

Mainfindings

Todate,12RBs(fromtheNordiccountriesandGermany)andoneRCTfromFinlandhaveinvestigatedtheeffectsofPTSLcomparedtoFTSLinmorethan2.74millionsick‐listedemployees.Allstudieshadmoderatemethodologicalquality,exceptoneRBs,whichhadhighmethodologicalquality.Thisindicatesconsistenthighinternalvalidityintheresearchmethodsused,butitisimportanttostressthatRBshavelimitedcapac‐itytodetectcausaleffects.TheFinnishRCTstudiedemployeeswhoweresick‐listedduetoMSDs,whiletheRBsincludedemployeeswithprimarilyeitherMSDsorMDs.Whilefirmconclusionscannotbedrawn,theRCTandtheRBssuggestedPTSLmaybeassociatedwithshortersicknessabsenceandhigherworkparticipation.TheFinnishRCTreportedthatemployeeswithPTSLexperiencedbettergeneralhealthandqualityoflifecomparedtothoseonFTSL.However,itdidnotfindstatisticaldifferencesbe‐tweenPTSLandFTSLonsickleaverecurrence,employees’productivityloss,andpain.TheRBsindicatedalowerprobabilityforpeopleonPTSLofreceivingbothdisabilitypensionandallowancebenefits,disability,aswellasbetterscoresonphysical‐andemotionalfunctioning,anxiety,depression,andworkingability.TheresultsregardingsicknessabsenceandworkparticipationaresupportedbyaNor‐wegianRB(26),whichusedthesameNAVdatasetasLie(43)andpartiallyMarkussenandcolleagues(49),bothincludedinthisreview.Kannandcolleagues(26)demon‐stratedthatanincreaseintherateofuseofPTSLinamunicipalityofonepercentagepoint(e.g.from13%to14%)wasassociatedwithareductioninthesicknessabsencerateof1.79%,andshortersicknessabsenceduration.Thatis,whentheproportionofdaysofsickleavethatweregradedincreasedbyonepercentagepoint,therateofsick‐nessabsencedecreasedbyabouttwopercent.Thus,theresearchersconcludedthatgreateruseofPTSLcaninsubsequentmonthsleadtoareductioninthesicknessab‐sencerate,durationofsicknessabsence,andnumberofindividualsonsickleave.Asimilaranalysiswithdatafrom2000to2011reachedthesameconclusions,althoughtheassociationsinthisanalysiswereweaker(46).Oursystematicmappingreviewidentifiedsomegapswithregardtothedifferentout‐comesmeasuredacrossstudies.Workparticipationwasthemostcommonoutcomere‐ported,measuredintenstudies,followedbysicknessabsenceduration,disability,disa‐bilitypensionandallowanceofsocialwelfarebenefits,withfourstudieseach.Incon‐trast,therecurrenceofsickleavewasonlymeasuredinonestudy(theRCT).Therewas

46 Discussion

animportantlackofknowledgeregardingtheeffectofPTSLforhealth‐relatedout‐comes,asonlytwostudiesaddressedthisissue(table6).Further,itshouldbenotedthattheoverwhelmingmajorityofthestudypopulationswereadultssufferingfrommusculoskeletal‐ormentaldisorders.Noneofthestudiesspecificallyincludedpeopleonsickleaveforotherreasons.ItispossiblethateffectsofPTSLarerelatedtodiagno‐sis.Forexample,Høgelundandcolleagues(29),whocombinedsurveyandregisterdataonabout850Danishworkers,foundthatPTSLhadnoeffectonthedurationuntilre‐turningtoregularworkinghoursforemployeeswithMDs,butsignificantlyreducedthedurationuntilreturningtoregularworkinghoursforemployeeswithotherdisorders.Generalizabilityandstrengthoffindings

TheOECDhasreportedthattheinsufficientlaborforceparticipationamongpeoplewithhealthissuesanddisability,theirlowincome,andthehighcostsofsicknessanddisabilitybenefitschemesrepresentaseriousproblemforgovernments,andtheuseofPTSLmightbeasuitablemeasuretocounteractthem(2).Animportantpointinfavorofthegeneralizabilityofthefavorablefindingsfromthestudiesincludedinthissys‐tematicmappingreviewisthepredominanceofNordicstudies.Elevenofthe13studieswerefromaNordiccountry,includingfourfromNorway.Further,aconsiderablegroupofemployeesintheincludedstudiesweresick‐listedduetoMSDsandMDs.TheformerrepresentsthemainoccupationaldiseasessufferedbyEuropeanworkers,accordingtotheEuropeanObservatoryofWorkingLife(55).InNorway,MSDsareamongthemostcommonreasonsforconsultationtoGPsandemergencyprimaryhealthcare,andrep‐resentthemajorityofdaytreatmentsinthenationalhealthsystem(56).Moreover,withregardtoMDs,datafromtheSwedishSocialSecurityAgencyshowthatMDsac‐countedforaroundhalfofallsickleavecasesamongwomenand40%ofallcasesamongmeninDecember2016.In2016,PTSLrepresentedaround30%ofallsickleavecasesandwasespeciallyhighamongpeoplewithMDs(14).AllRBsuseddatafromstructurednationwideregistries.TheNorwegianstudiesuseddatafromNAV,whichmightfacilitatetheformulationofpublicpoliciesandfurtherre‐searchoftheuseofPTSLforcontrollingsicknessabsence.WenotethatthetwoGer‐manstudiesconcernedatotalofabout4500employees–andthereforecontributeslesstotheoverallfindings–whocompletedarehabilitationprogram,whichismanda‐toryinGermany,butnotstandardpracticeinNorwaywherepeoplegenerallystartPTSLearlyinthecourseofthesicknessabsence.InGermany,PTSLisgrantedwhenthesick‐listedemployeehascompletedtherehabilitationprogrambutisstillunabletoperformfullduties,anditisapprovedbytherehabilitationphysicianandthesocialworkerwithconsentfromtheemployer,thepatient,thegeneralpractitionerandtheoccupationalphysician(57‐59).Aspartoftheschemedevelopedbytherehabilitationphysician,thesick‐listedemployeestartsworkingforatleasttwohours/dayandgrad‐uallyincreasestheworkingtime(58;59).

47 Discussion

Strengthofevidence

Thetwotypesofstudydesignsandresearchapproachesthatrepresentthebodyofevi‐denceontheeffectsofPTSLversusFTSLmeritsomediscussionintermsofthepossi‐bilitytodrawcausalinferencesfromtheirfindings.TheFinnishRCTrepresentsthestrongeststudydesigntoanswertheresearchquestionthatguidedthissystematicmappingreview,asitiswidelyacceptedthatwell‐conductedprospective,experimentalstudieshavethegreatestcapacitytodetectcausaleffectsduetotheirpossibilitytoran‐domlyassignindividualstodifferentexposures,andthereforeensurethatgroupsaresimilar(60).Essentialsupportforthisstatementmaybebasedonthecounterfactualapproachforevaluatingcausalinferenceinepidemiology,whicharguesthatahighcomparabilitybetweenexposedandunexposedindividualsisneededtoestimateanycausaleffect,asitisnotpossibletoobserveanindividual’soutcomebothatthetimewhenheisexposedandatthesametimewhenheisnot(61‐63).Nevertheless,randomassignmentisnotsufficienttoensurehighvalidityofexperimentalstudies,asalsothesemayhavelimitationsthatcanleadtobiasedestimatesofcausaleffects(e.g.,lowadherencetotheintervention,highattrition,andoutcomemeasurementerrors)(40‐42;64;65).Additionally,ethicalconstraintsforconductingexperimentalresearchareacommonconcernthatturnsthefocustoobservationaldata.Inspiteofthepreferenceforexperimentalstudieswhenaddressingquestionsabouteffect,andasnoticedinourfindings,thebodyofevidenceaboutthebenefits/draw‐backsofPTSLcomparedtoFTSLismostlyrepresentedbyRBsthatuseobservationaldataderivedfromnationwideregistries.Whileabroaddiscussionaboutcausalinfer‐encegoesbeyondthescopeofthissystematicmappingreview,weofferafewnotesaboutthecapacitytodrawcausalinferencesfromobservationaldata.Observationalstudiesestimatedifferencesonacertainoutcome“X”amongindividualswithdifferentlevelsofanexposure“Y”(63;66),andnumerousmethodologicalapproachesarede‐scribedintheliteraturetoestimatecausaleffectsbasedontheirdata(62;63;66).Someofthemajorconstraintstodetectcausalinferencesinobservationaldataaretiedtothesusceptibilityofselectionbiasduetoanon‐randomdistributionoftheexposure,thepossibilityofconfounding,reversecausation,andtheoptiontoseeoutcomedatabe‐foretheallocationoftheindividualstothegroupsofstudy(62;67).Outcomedataanal‐ysisisnotprecededbytheallocationoftheindividualstodifferentexposurelevels,thusanequaldistributionofcovariatesbetweenexposedandunexposedindividualsmaynotbeensured(66;6