Monday, August 13, 2007NASUG 2007 METAANALYTIC INTEGRATION OF DIAGNOSTIC ACCURACY STUDIES IN STATA Ben A. Dwamena, MD Department of Radiology (Nuclear

Monday, August 13, 2007 NASUG 2007

METAANALYTIC INTEGRATION OF DIAGNOSTIC ACCURACY STUDIES IN STATA

Ben A. Dwamena, MDDepartment of Radiology (Nuclear Medicine)


WHY META-ANALYSIS?


WHY META-ANALYSIS?


2 X 2 TABLE FOR SINGLE STUDY


THESHOLD EFFECT AND ROC


VARIATION IN THRESHOLD VS ACCURACY


TRADITIONAL MODEL


EXAMPLE DATA





LIMITATIONS OF SROC MODEL


BIVARIATE MIXED-EFFECTS BINOMIAL REGRESSION MODEL












BINOMIAL REGRESSION MODELXTMELOGIT CODE


BINOMIAL REGRESSION MODEL GLAMM CODE


EXAMPLE DATASET:Axillary PET Scan in Primary Breast Cancer


SYNTAX FOR midas


QUALITY ASSESSMENTmidas tp fp fn tn prodesign ssize30 fulverif testdescr refdescr subjdescr ///

report brdspect blinded, id(author) year(year) qualib

0 20 40 60 80 100percent

blinded

brdspect

fulverif

prodesign

refdescr

report

ssize30

subjdescr

testdescr

BAR GRAPH OF QUALITY ASSESSMENT

Yes No


ROC PLANEmidas tp fp fn tn, id(author) year(year) es(x) rocp


CHI-PLOTmidas tp fp fn tn, id(author) year(year) ms(0.75) chip


BIVARIATE BOXPLOTmidas tp fp fn tn, id(author) year(year) ms(0.75) bivbox


SUMMARY RESULTS midas tp fp fn tn, id(author) year(year) es(x) ms(0.75) sumstats


SUMMARY RESULTS:midas tp fp fn tn, id(author) year(year) ms(0.75) es(x) sumstats


SUMMARY ROC midas tp fp fn tn, es(x) ms(0.75) plot sroc1


SUMMARY ROC midas tp fp fn tn, es(x) ms(0.75) plot sroc2


FOREST PLOTmidas tp fp fn tn, id(author) year(year) es(x) ms(0.75) ford for(dss)

DLR POSITIVE (95% CI)

27.28[9.81 - 75.84]

1.80 [0.81 - 3.99]7.56 [1.68 - 34.04]2.39 [1.03 - 5.56]7.60 [1.69 - 34.19]5.89 [2.62 - 13.23]1.91 [0.90 - 4.05]15.55 [1.04 - 232.22]83.52 [5.26 - 1000.00]26.42 [1.69 - 414.06]9.78 [2.09 - 45.72]8.33 [1.84 - 37.69]14.25 [3.72 - 54.57]5.02 [2.52 - 10.00]7.18 [2.24 - 23.03]31.57 [2.04 - 488.19]3.34 [1.64 - 6.80]3.44 [1.90 - 6.24]18.05 [6.90 - 47.22]9.35 [4.53 - 19.32]4.00 [1.48 - 10.84]4.00 [1.48 - 10.84]

STUDY(YEAR)

Q = 67.63, df = 19.00, p = 0.00I2 = 59.30 [59.30 - 84.51]

COMBINED

Tse 1992Adler1 1993

Hoh 1993Crowe 1994

Avril 1996Bassa 1996

Scheidhauer 1996Utech 1996Adler2 1997

Palmedo 1997Noh 1998

Smith 1998Rostom 1999Yutani1 1999Hubner 2000

Ohta 2000Yutani2 2000

Greco 2001Schirrmeister 2001

Yang 2001

0.8 1000.0DLR POSITIVE


FOREST PLOTmidas tp fp fn tn, id(author) year(year) es(x) ms(0.45) for(dss)

STUDY(YEAR)

Q = 40.28, df = 19.00, p = 0.00I2 = 52.84 [28.82 - 76.85]

COMBINED

Tse 1992Adler1 1993

Hoh 1993Crowe 1994

Avril 1996Bassa 1996

Scheidhauer 1996Utech 1996

Adler2 1997Palmedo 1997

Noh 1998Smith 1998

Rostom 1999Yutani1 1999Hubner 2000

Ohta 2000Yutani2 2000

Greco 2001Schirrmeister 2001

Yang 2001

0 3DLR NEGATIVE


FUNNEL PLOTmidas tp fp fn tn, ms(0.75) fun


FUNNEL PLOT ASYMMETRY TESTmidas tp fp fn tn, pubb


CONDITIONAL PROBABILITY PLOTmidas tp fp fn tn, es(x) pddam(p)


UNCONDITIONAL PREDICTIVE VALUESmidas tp fp fn tn, ms(0.75) es(x) pddam(r)


FAGAN’S NOMOGRAM Imidas tp fp fn tn, es(x) fagan


FAGAN’S NOMOGRAM IImidas tp fp fn tn, es(x) fagan prior(.20)


LIKELIHOOD RATIO SCATTERGRAMmidas tp fp fn tn, es(x) lrmat


UNIVARIABLE META-REGRESSIONmidas tp fp fn tn prodesign brdspect

blinded, covars


WORK-IN-PROGRESS

Extending bivariate model to assess: Publication bias using

association-marginal modeling Influencial Studies Heterogeneity using ICCs Nonparametric modeling of

random effects etc


THANK YOU FOR YOUR ATTENTION

QUESTIONS?

SUGGESTIONS

COMMENTS


ACKNOWLEDGEMENTS

Documents

Monday, August 13, 2007NASUG 2007 METAANALYTIC INTEGRATION OF DIAGNOSTIC ACCURACY STUDIES IN STATA Ben A. Dwamena, MD Department of Radiology (Nuclear