Systematic Review

Can lay health workers increase the uptake of childhood

immunisation? Systematic review and typology

Claire Glenton1, Inger B. Scheel1, Simon Lewin2 and George H. Swingler3

1 SINTEF Health Research, Department of Global Health and Research, Norway2 Norwegian Knowledge Centre for the Health Services, Oslo, Norway3 Department of Paediatrics & Child Health, University of Cape Town, South Africa

Summary objectives Lay health workers (LHWs) are used in many settings to increase immunisation uptake

among children. However, little is known about the effectiveness of these interventions. The objective of

this review was to assess the effects of LHW interventions on childhood immunisation uptake.

methods We searched Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE,

CINAHL, British Nursing Index and Archive, AMED, POPLINE and WHOLIS, reference lists of included

papers and relevant reviews, and contacted the authors of relevant papers. We selected randomised and

non-randomised controlled trials, controlled before–after studies, and interrupted time series of any

intervention delivered by LHWs and designed to increase childhood immunisation uptake. Two authors

independently extracted data using a standard form and assessed risk of bias and evidence quality.

findings We identified twelve studies, ten of which were randomised controlled trials. Seven studies were

conducted among economically disadvantaged populations in high-income countries. Five studies were from

low- and middle-income countries. In ten studies, LHWs promoted childhood immunisation. In two studies,

LHWs vaccinated children themselves. In most of the studies, the control group populations received no

intervention or standard care. Most of the studies showed that LHWs increased immunisation coverage.

However, study settings were diverse, allowing us to carry out only one meta-analysis including four studies.

conclusion LHWs could make an important contribution to achieving the Millennium Development

Goal for child health. However, more high-quality studies are needed, particularly from LMICs. More

studies are also needed to assess the effects of using LHWs to vaccinate children themselves.

keywords community health aides, review

Introduction

The United Nations’ Millennium Development Goal 4 is to

reduce by two-thirds the mortality rate of children under

the age of five. A key measure in the achievement of this

goal is universal coverage of primary healthcare services,

including full coverage of immunisation programmes. Lay

or community health workers are expected to play a role in

the delivery of these services (United Nations 2008).

Lay health workers (LHWs) are health workers who

perform diverse functions related to healthcare delivery but

who have no formal professional training (Lewin et al.

2005). LHW programmes flourished in the 1970s and have

received new attention in recent years, partly in response to

the human resource crisis in health. In immunisation

programmes, LHWs are used most commonly to promote

immunisation uptake, but in some programmes, LHWs are

also trained to give vaccinations.

LHWs may be men or women, young or old, illiterate or

highly educated (Lehmann & Sanders 2007). LHW

programmes commonly emphasise the importance of

recruiting staff from the communities they serve. In this

way, they aim to increase the population’s access to care,

ease the health workers’ knowledge of and access to hard-

to-reach groups in the community, and, in many instances,

facilitate and encourage community empowerment and

self-sufficiency. Many programmes also emphasise the

importance of community participation, for instance in the

selection of LHWs, although this may be less often

implemented in practice (Lehmann & Sanders 2007).

The renewed interest in LHW programmes has generally

occurred in the absence of robust evidence of their effect,

Tropical Medicine and International Health doi:10.1111/j.1365-3156.2011.02813.x

volume 16 no 9 pp 1044–1053 september 2011

1044 ª 2011 Blackwell Publishing Ltd

cost-effectiveness and potential adverse effects. In Lewin

et al. (2010) published a Cochrane systematic review

examining the global evidence from randomised trials on

the effects of LHW interventions in primary and

community health care for maternal and child health and

the treatment of infectious diseases. This review identified

six randomised trials that evaluated the use of LHWs for

childhood immunisation uptake. While these studies indi-

cated promising benefits, they offered little evidence

regarding the effects of such programmes in low- and

middle-income countries (LMICs). In an attempt to iden-

tify a larger evidence base, members of the original review

team carried out a new review, expanding our criteria to

include studies using controlled before–after and inter-

rupted time-series designs. We also aimed to explore how

LHWs were being used in immunisation programmes and

to develop a typology of these interventions. Our objectives

were to assess the effects of LHW interventions on the

uptake of childhood immunisation and to develop a

typology of intervention models.

Methods

Eligibility criteria

Randomised and non-randomised controlled trials, con-

trolled before–after studies, and interrupted time series

were eligible for inclusion, as were studies where the

intervention targeted any person, including parents or

community members, and where the aim was to increase

immunisation coverage among children under 5 years of

age. We considered any intervention delivered by LHWs

which aimed to increase childhood immunisation coverage.

We defined an LHW as any health worker carrying out

functions related to healthcare delivery, trained in some

way in the context of the intervention, and having no

formal professional or paraprofessional certificated or

degreed tertiary education (Lewin et al. 2005). We included

studies where LHWs were used as a substitute for trained

health professionals or in addition to health professionals.

We excluded studies if they were based outside of primary

health care, such as in hospitals or schools. Comparisons

were made between studies that delivered interventions by

LHWs with no intervention and standard care, or the same

intervention delivered by health professionals.

In terms of outcome measures, primary outcomes

considered were measures of immunisation coverage,

including immunisation schedule up to date and any

immunisation, and harmful effects. Secondary outcomes

were all-cause mortality, disease-specific mortality, inci-

dence of specific diseases and hospitalisation for specific

diseases.

Search methods

We searched multiple electronic databases until February

2009 (Figure S1) as well as the reference lists of included

papers and relevant reviews and contacted authors of

relevant papers regarding any additional published or

unpublished work.

Selection of trials

Two reviewers independently assessed the potential rele-

vance of all titles and abstracts identified. We retrieved full-

text copies of the articles identified as potentially relevant

by either one or both reviewers. Each full paper was then

evaluated independently for inclusion by at least two

reviewers. When reviewers disagreed, a third reviewer

made an independent assessment.

Assessment of quality of the evidence in included studies

Two reviewers independently assessed the risk of bias for

each study using the Cochrane Collaboration’s Risk of Bias

tool (Higgins & Green 2009). For non-randomised trials,

we used the Cochrane EPOC Group’s adaptation of this

tool (Cochrane Effective Practice and Organisation of Care

Group 2009). We also evaluated the quality of evidence

related to key outcomes using the GRADE approach

(Higgins & Green 2009).

Data extraction and management

Two reviewers independently extracted data from each

study. Discrepancies were discussed by the two reviewers

and resolved by consensus. We also attempted to supple-

ment study information by contacting study authors and

reading related publications. We extracted data about the

following aspects:

• study design;

• geographic setting (country, urban or rural) and

healthcare setting (clinic, community, or home);

• participants (age, socioeconomic characteristics,

number enrolled at baseline, number and proportion

followed up);

• intervention (services performed, selection criteria,

training, supervision, education level,gender, incentives

provided,number ofLHWstrainedand attrition levels);

• control group intervention, if any;

• results for the selected outcomes.

Data synthesis

After grouping studies that compared broadly similar

types of interventions, we combined the feasible results

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

ª 2011 Blackwell Publishing Ltd 1045

to obtain an overall estimate of effect. Data were re-analysed

on an intention-to-treat basis where possible. Beneficial

health behaviours were analysed on a worst case basis for

individuals; that is, persons lost to follow-up were assumed

to be non-adherent to the beneficial health behaviours.

Adjustment for clustering was made for studies that used

a cluster-randomised design, but did not account for this

adequately in their analysis. No information on the intra-

cluster correlation coefficient (ICC) was reported in any of

the included cluster RCTs. If results at the cluster level were

reported, we performed a formal re-analysis where clus-

tering was taken into account by calculating the variance

within each cluster and aggregating these to a common

estimate of the population variance. Using these cluster-

adjusted variances, we estimated the ICC. The largest ICC

obtained from these formal re-analyses of data from the

included studies was used as the basis for re-analysis of data

from studies where cluster level data were not available as

this provides the most conservative adjustment estimate. To

assess the impact of our ICC assumption, we also carried

out an additional sensitivity analysis using an ICC of 0.02,

as this ICC has been reported as typical of primary and

community care interventions (Campbell et al. 2000). This

analysis is presented in an additional figure (Figure S2). Log

relative risks and standard errors of the log relative risk

were then calculated for both individual and cluster RCTs

(unadjusted). The unadjusted standard errors for cluster

RCTs were then adjusted for the effect of clustering using

the multiplicative factor square root of the design

effect = (1 + (mean cluster size)1)*ICC). The log relative

risks for individual RCTs and the adjusted log relative risks

for cluster RCTs were analysed together using the generic

inverse variance method in Cochrane Review Manager 5.

Random effects meta-analysis was preferred because the

studies were heterogeneous.

Results

Results of the search

We identified a total of 3315 titles (excluding duplicates) and

considered 55 full text papers for inclusion in the review. Ten

studies met our inclusion criteria. In addition, we included

one study that had been published after our search had taken

place and one study that we identified from a literature

review (Bhutta et al. 2010), bringing the final number of

included studies to twelve (Figure 1: Flowchart). Charac-

teristics of the included studies are described in Figure S3.

Study design

We included six randomised trials (Barnes et al. 1999;

Colombo et al. 1979; Gokcay et al. 1993; Johnson et al.

1993; LeBaron et al. 2004; Rodewald et al. 1999) that

were also included in the Cochrane review (Lewin et al.

2010). In addition, we included the following:

• Two randomised trials (Norr et al. 2003; Brugha &

Kevany 1996), which were not included in the

Cochrane review because the intervention was deliv-

ered by a nurse–LHW team and the effects of the

LHWs alone could not be ascertained.

• One randomised trial (Andersson et al. 2009), which

was published too late to be included in the Cochrane

review.

• One randomised trial (Lechtig et al. 1981), which was

considered to be of too low quality to be included in

the Cochrane review as the study only included two

units of analysis, and is therefore at high risk of

confounding of intervention and context effects.

• One controlled before–after study (Alto et al. 1989).

• One interrupted time-series study (Stewart & Hood

1970).

Setting and population

Seven of the studies were conducted in high-income

countries: six in the USA (Barnes et al. 1999; Colombo

1318 duplicates excluded

10 studies included

44 articles excluded due to study design, intervention, or target

population.

4633 titles identified

3315 identified and screened for retrieval

3260 articles excluded due to study design, intervention, setting, population,

or unable to access full text

1 article published after searches were finalised, and 1 article identified through searches in relevant literature reviews

12 studies included

55 articles retrieved for more detailed evaluation

Figure 1 Flowchart.

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

1046 ª 2011 Blackwell Publishing Ltd

et al. 1979; LeBaron et al. 2004; Rodewald et al. 1999;

Norr et al. 2003; Stewart & Hood 1970) and one in

Ireland (Johnson et al. 1993). The remaining 5 studies were

carried out in Ghana (Brugha & Kevany 1996), Guatamala

(Lechtig et al. 1981), Pakistan (Andersson et al. 2009),

Papua New Guinea (Alto et al. 1989) and Turkey (Gokcay

et al. 1993).

The studies from USA and Ireland took place in urban

settings among populations described as economically

disadvantaged. The LMIC-based studies took place in both

urban and rural settings, among study populations

described as poor, or from areas where immunisation rates

were particularly low.

Interventions

Broadly speaking, the interventions used in these studies

can be split into two main types: interventions where

LHWs promoted immunisation uptake and interventions

where LHWs vaccinated children. In the studies from USA,

Ireland, Turkey and Ghana, LHWs made home visits to

parents, giving them information about the importance of

routine childhood immunisations and encouraging them to

visit clinics for child immunisation. In four of these studies

(Colombo et al. 1979; Gokcay et al. 1993; Johnson et al.

1993; Norr et al. 2003), this information was given as part

of a package of information and promotion about child

health. In two of the studies, LHWs collaborated with

nurses (Norr et al. 2003; Brugha & Kevany 1996). In

Pakistan, LHWs led focus group meetings with selected

members of the community where they discussed current

immunisation coverage, expected risks of measles and risks

and benefits of immunisation, barriers to immunisation

and possible solutions. Focus group participants were then

expected to spread the contents of these meetings to their

communities.

In Guatemala and Papua New Guinea, the vaccines were

given by the LHWs themselves. In Papua New Guinea,

routine childhood immunisations were given by clinic-

based LHWs. In Guatemala, LHWs also gave routine

immunisations, but it was unclear where this took place.

It is unclear whether these interventions also included

information or education.

There were a number of differences in LHW character-

istics across the twelve studies. In most studies, efforts were

made to select LHWs who resembled their target popula-

tions in terms of gender, place of residence, and in some

cases, level of education, but this was not always the case.

There were also variations in the amount of contact

between the LHWs and the communities they served; for

instance, in Ireland and Turkey, mothers were visited on

several occasions by LHWs who were mothers from the

same community, while in Ghana, the LHWs were high

school students from outside the area who met their target

families only once.

In two studies (Norr et al. 2003; Alto et al. 1989), the

LHWs were selected by the community or by community

organisations. In seven studies (Barnes et al. 1999; Gokcay

et al. 1993; Johnson et al. 1993; LeBaron et al. 2004;

Brugha & Kevany 1996; Andersson et al. 2009; Stewart &

Hood 1970), the LHWs were selected by professional

health workers, the research team or other people respon-

sible for the programme. Three studies (Colombo et al.

1979; Rodewald et al. 1999; Lechtig et al. 1981) provided

no information on this issue. Most LHWs received 1 week

to a few months training. One exception is the Papua New

Guinean LHWs who received 1 year’s generalist training.

(Information regarding number of LHWs, incentives and

attrition rates, where it was available, can be found in

Figure S3.)

Comparisons

In most studies, the control group population received no

intervention or standard care. There were three exceptions:

in Turkey, LHWs making home visits were compared with

midwives making home visits; in Papua New Guinea,

LHWs who had been trained to give immunisations were

compared with health professionals who had received the

same training; and in one of the US-based studies (Barnes

et al. 1999), LHWs who made home visits and phone calls

over a maximum of 6 months were compared with study

personnel making one home visit.

Outcome measures

With two exceptions (Colombo et al. 1979; Stewart &

Hood 1970), all studies reported data for ‘immunisation up

to date’. Four studies (Brugha & Kevany 1996; Johnson

et al. 1993; Lechtig et al. 1981; Stewart & Hood 1970)

also reported data for ‘any immunisation’. The type,

number and timing of vaccines that were measured

varied from setting to setting, and included the up-to-date

delivery of full schedules of several different vaccines, full

schedules of one vaccine, or the single delivery of one

vaccine. Vaccines included diphtheria, tetanus, pertussis,

polio, Haemophilus influenzae type B, Hepatitis B,

measles, mumps, rubella, BCG and ‘Pigbel’ (Enteritis

necroticans).

None of the identified studies reported data for hospi-

talisation for specific diseases or harmful effects. One study

(Lechtig et al. 1981) reported data for infant and child

deaths, but we have not reported these data because of

study design limitations.

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

ª 2011 Blackwell Publishing Ltd 1047

Risk of bias of included studies

Assessments of the risk of bias for included studies are

shown in Figure 2 and Figure S3.

Adjustment for clustering

Three trials were cluster randomised (Andersson et al.

2009; Brugha & Kevany 1996; Gokcay et al. 1993).

Although two of these studies (Andersson et al. 2009;

Brugha & Kevany 1996) were adjusted for clustering, they

did not report risk ratios or ICCs and further analysis was

therefore required to calculate these. Gokcay et al. (1993)

appeared to have made no adjustments for clustering.

Andersson et al. (2009) provided data on the cluster

level which made a formal re-analysis possible. For the

outcome ‘Proportion of children (12–23 months) reported

to have received measles vaccine’, the ICC was estimated as

0.25, and for the ‘Proportion of children (12–23 months)

reported to have received a full course of DPT (diphtheria,

pertussis and tetanus) vaccine’, the ICC was estimated as

0.14. As a consequence, an ICC of 0.25 was used for re-

analysis of the data from Brugha & Kevany (1996). There

were insufficient data to conduct re-analysis for Gokcay

et al. (1993).

Adjustment for intention to treat (ITT)

One study (LeBaron et al. 2004) used ITT analysis. For

three studies, ITT analysis was not applicable as these were

cluster RCTs and the individual patient data were drawn

from cross-sectional surveys of children’s immunisation

status (Brugha & Kevany 1996, Andersson et al. 2009,

Alto et al. 1989). In five studies, the authors presented

insufficient data to allow us to conduct any further ITT

analysis (Colombo et al. 1979, Gokcay et al. 1993, Norr

et al. 2003, Lechtig et al. 1981, Stewart & Hood 1970).

For three studies, the authors did not present an ITT

analysis, but provided sufficient data to allow us to

conduct this. For these analyses, we used the total number

of children randomised as the denominator and we

assumed that children not followed up had a negative

outcome (Barnes et al. 1999, Johnson et al. 1993,

Rodewald et al. 1999).

Effects of the interventions

Numerical results for each relevant outcome reported in

the studies are shown in two forest plots (Figures 3 and 4).

In six studies (Barnes et al. 1999; Colombo et al. 1979;

Johnson et al. 1993; LeBaron et al. 2004; Rodewald et al.

1999; Stewart & Hood 1970), LHWs promoted immuni-

sation uptake among economically disadvantaged families

in high-income countries. Four of these studies were

considered similar enough to be included in a meta-analysis

(Barnes et al. 1999; Johnson et al. 1993; LeBaron et al.

2004; Rodewald et al. 1999). The LHW programmes

increased the number of children whose immunisations

were up to date (RR 1.19, 95% CI 1.09–1.30;

P = <0.0001). This evidence was of moderate quality. In

three studies, the LHW intervention was compared with no

intervention or standard care. In one study (Barnes et al.

1999), the comparison group received an immunisation

reminder. The results could be interpreted as heteroge-

neous suggesting that LHW interventions have variable

effects (Table 1, Figure 3). The study by Colombo et al.

(1979) was not included in the meta-analysis because it did

not provide sufficient data and because it reported the

number of children using preventive services, including

Study

Ade

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Blin

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Inco

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ome

data

ad

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Fre

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sel

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port

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Fre

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er b

ias?

Alto 1989

Andersson 2009

Barnes 1999

Brugha 1996

Colombo 1979

Gökçay 1993

Johnson 1993

LeBaron 2004

Lechtig 1981

Norr 2003

Rodewald 1999

Stewart 1970

Figure 2 Risk of bias summary.

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

1048 ª 2011 Blackwell Publishing Ltd

immunisation, rather than ‘immunisation up to date’. The

study by Stewart and Hood (1970) was not included in the

meta-analysis because it used an interrupted time-series

design and because it measured ‘any immunisation’ rather

than ‘immunisation up to date’. Both studies suggested an

effect in favour of LHWs.

In two studies, LHWs promoted immunisation uptake

among families in LMICs. In Turkey (Gokcay et al. 1993),

LHWs promoted immunisation uptake among mothers in a

squatter area. This was compared with the same interven-

tion delivered by midwives. There was no difference

between the LHW group and control group in the

proportion of children whose immunisations were up to

date. This evidence was of low quality. In Pakistan

(Andersson et al. 2009), LHWs promoted immunisation

uptake at a series of village meetings with selected

community members. This was compared with no inter-

vention. The LHW programme increased the number of

children whose DPT and measles immunisations were up

to date. This evidence was of moderate quality (Figure 4).

In two studies, LHWs promoted immunisation uptake

among families in collaboration with nurses. As these

interventions were compared with no intervention or

standard care, it was not possible to isolate the impact of

the LHWs alone. In Ghana (Brugha & Kevany 1996),

the LHW–nurse programme increased the number of

children whose measles and polio immunisations were up

to date. This evidence was of low quality. In the USA

(Norr et al. 2003), the LHW–nurse programme made no

difference to the number of children whose childhood

immunisations were up to date in the African–American

subgroup. In the Mexican–American subgroup, the

number of children whose immunisations were up to date

was higher in the control group. This evidence was of

low quality (Figure 4).

In two studies, vaccines were given by the LHWs.

In rural Papua New Guinea (Alto et al. 1989), LHWs

increased the number of children whose DPT, measles,

polio and BCG vaccines were up to date compared with

health professionals who had received the same training in

vaccine delivery. However, the study showed an increase in

favour of the control group for the ‘Pigbel’ (Enteritis

necroticans) vaccine. In rural Guatemala (Lechtig et al.

1981), LHWs increased the number of children whose

Study or Subgroup

Barnes 1999Johnson 1993LeBaron 2004Rodewald 1999

Total (95% CI)

Heterogeneity: τ2 = 0.00: χ2 = 4.62, df = 3 (P = 0.20); l 2 = 35%

Test for overall effect: Z = 4.01 (P < 0.0001)

0.00990.30740.08610.1906

0.19630.0912

0.070.0295

4.7%17.4%25.1%52.8%

100.0%

1.01 [0.69, 1.48]1.36 [1.14, 1.63]1.09 [0.95, 1.25]1.21 [1.14, 1.28]

1.19 [1.09, 1.30]

0.5 0.7 1 1.5 2Favours interventionFavours control

log [CC] SE Weight IV, Random, 95% CI IV, Random, 95% CICC CC

Figure 3 LHWs to promote childhood

immunisation - high income countries

(outcome: immunisation up-to-date).Source: Adapted from LHW Cochrane

review, analysis 1.3 (Lewin et al. 2010).

Study or Subgroup

Alto (BCG) 0.0583 0.0072 1.06 [1.05, 1.08]1.16 [1.10, 1.22]1.29 [1.20, 1.39]0.87 [0.83, 0.91]1.12 [1.07, 1.18]2.17 [1.43, 3.29]1.63 [1.03, 2.58]1.29 [1.09, 1.53]1.26 [1.09, 1.46]1.07 [0.99, 1.16]1.22 [1.05, 1.42]

1.03 [0.91, 1.17]0.87 [0.76, 0.99]

0.2 0.5 1 2 5

Not estimableNot estimableNot estimable

0.1484 0.02640.2546 0.0375

–0.13930.1133 0.02520.7734 0.21240.4889 0.23470.2546 0.08710.2311 0.07350.0677 0.04170.1989

0 00 00

0.0296–0.1393

(1) Adjusted for clustering using ICC of 0.14(2) Adjusted for clustering using ICC of 0.25(3) All outcomes from Brugha adjusted for clustering using ICC of 0.25(4) Insufficient data(5) Insufficient data(6) Insufficient data(7) AA: African-American population(8) MA: Mexican-American population

0.06740.0647

0

0.0759

0.0235

Alto (DPT)Alto (Measles)Alto (Pigbel)Alto (Polio)Andersson (DPT) (1)Andersson (Measles) (2)Brugha (0<vacc) (3)Brugha (Measles)Brugha (Polio 1)Brugha (Polio 3)Gokcay (Children<5) (4)Gokcay (Infants) (5)Lechtig (6)Norr (AA) (7)Norr (MA) (8)

log [Risk ratio] SE IV, Random, 95% CI IV, Random, 95% CIRisk ratioRisk ratio

Favours experimentalFavours controlFigure 4 LHW involvement in childhood

immunization (outcome: immunisationup-to-date) (Main analysis). The included

studies used LHWs to promote or give

immunizations, either alone or with nurses.These studies were not included in any

meta-analysis.

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

ª 2011 Blackwell Publishing Ltd 1049

measles vaccines were up to date and who had received any

DPT or polio vaccine, compared with standard care.

However, it is unclear whether these differences were

statistically significant. The quality of the evidence was

very low. As both studies included only two units of

analysis, any effect of the interventions may have been

confounded by contextual differences between the inter-

vention and control areas (Figure 4).

Discussion

The majority of studies identified in this review showed

promising benefits in improving child immunisation cov-

erage (Table 1, Figure 4). This is a potentially important

finding for policy makers as these interventions, if scaled

up, may help to achieve the Millennium Development Goal

for child health. Some of the studies also showed innova-

tive ways of expanding immunisation coverage; for

instance, while most interventions involved direct com-

munication between LHWs and mothers of children in

need of immunisations, Andersson et al. (2009) suggests

that coverage can increase in whole communities through

structured discussions with selected members of these

communities.

Immunisation interventions are often part of a larger

package where LHWs take on a range of child health-

related functions or work within a wider team, including

nurses, midwives and doctors, to deliver care to children.

The findings of this review, together with the results of the

wider Cochrane review (Lewin et al. 2010), illustrate the

potential for LHWs to contribute to a package of effective

child health interventions (Arifeen et al. 2009; Mann et al.

2009; Armstrong Schellenberg et al. 2004). However,

further evidence is needed on how best to integrate these

different primary healthcare services (Briggs & Garner

2006).

Evidence remains limited

The diversity of the studies allowed us to carry out only one

meta-analysis. While this meta-analysis showed moderate

quality evidence that LHW programmes can increase

Table 1 Summary of findings table

LHWs to promote childhood immunisation among parents (high-income countries)

Patients or population: Children under 2 years of age from economically disadvantaged familiesSettings: Urban settings in USA (3 studies) and Ireland (1 study)

Intervention: Lay health workers (LHWs) promoting immunisation to parents

Comparison: Standard care or one visit by study personnel

Outcomes

Impact

Relative

effect (95% CI)

Number ofparticipants

(studies)

Quality of theevidence

(GRADE)Without LHWs With LHWs

Immunisationup-to-date

482 per 1000children

574 per 1000children (525–627

children)

RR 1.19 (1.09–1.30) 3568 (4 studies*) ¯¯¯s Moderate��§

CI: Confidence interval; RR: Risk ratio; GRADE: GRADE Working Group grades of evidence (see explanation below)

GRADE Working Group grades of evidence:

¯¯¯¯ High quality: We are very confident that the true effect lies close to that of the estimate of effect.¯¯¯s Moderate quality: We are moderately confident in the effect estimate: The true effect is likely to be close to the estimate of the

effect, but there is a possibility that it is substantially different.

¯¯ss Low quality: Our confidence in the effect estimate is limited: The true effect may be substantially different from the estimate of

effect.¯sss Very low quality: We have very little confidence in the effect estimate: The true effect is likely to be substantially different from the

estimate of effect.

*Barnes et al. 1999; Johnson et al. 1993; LeBaron et al. 2004; Rodewald et al. 1999.

�In the study by Barnes et al. 1999; only 37.5% of eligible families consented to participate, 21.2% refused to participate and 14.3% were

living out of the country or in another state. A significantly greater percentage of non-enrolled children were covered by Medicaid insurancethan enrolled children (P = 0.02). The quality of evidence was downgraded by 0.5 because of these design limitations (also see footnote ‘‘§’’).

�In the study by Johnson et al. 1993; the outcomes were recorded by a family development nurse who knew the group assignment of the

mother–child pair.§There is wide variation in the estimates of the included studies from no effect to a 36% relative increase. The quality of evidence was

downgraded by 0.5 because of these inconsistencies.

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

1050 ª 2011 Blackwell Publishing Ltd

Tab

le2

Aty

polo

gy

of

lay

hea

lth

work

er(L

HW

)pro

gra

mm

esfo

rim

munis

ati

on

HW

inte

rven

tion

model

for

vacc

inati

on

Org

anis

ati

on

of

care

LH

Wta

sks

LH

Ws

sele

cted

on

the

basi

sof

bei

ng

pee

rs*

LH

Ws

giv

enso

me

form

of

rem

uner

ati

on�

Task

sdel

iver

edby

LH

Ws

alo

ne

Task

sdel

iver

edby

ate

amof

hea

lth

work

ers,

incl

udin

gL

HW

sIm

munis

ati

on

only

Gen

erali

stY

esN

oY

esN

o

Model

1:

Pro

vis

ion

of

info

rmat

ion

and

support

by

LH

Ws

topare

nts

⁄care

rs

Cam

pbel

let

al.

(2000);

Coch

rane

Eff

ecti

ve

Pra

ctic

eand

Org

anis

ati

on

of

Care

Gro

up

(EPO

C)

(2009);

Colo

mbo

etal

.(1

979);

Corl

uka

etal

.(2

009);

Gokca

yet

al.

(1993);

Hig

gin

s&

Gre

en(2

009);

Lew

inet

al.

(2010)

Johnso

net

al.

(1993);

LeB

aro

net

al.

(2004)

Lec

hti

get

al.

(1981);

Gokca

yet

al.

(1993);

Cam

pbel

let

al.

(2000);

LeB

aron

etal

.(2

004);

Hig

gin

s&

Gre

en(2

009);

Lew

inet

al.

(2010)

Coch

rane

Eff

ecti

ve

Pra

ctic

eand

Org

anis

ati

on

of

Care

Gro

up

(EPO

C)

(2009);

Colo

mbo

etal

.(1

979);

Corl

uka

etal

.(2

009);

Johnso

net

al.

(1993)

Cam

pbel

let

al.

(2000);

Coch

rane

Eff

ecti

ve

Pra

ctic

eand

Org

anis

ati

on

of

Care

Gro

up

(EPO

C)

(2009);

Colo

mbo

etal

.(1

979);

Corl

uka

etal

.(2

009);

Gokca

yet

al.

(1993);

Hig

gins

&G

reen

(2009);

Johnso

net

al.

(1993);

Lew

inet

al.

(2010)

LeB

aro

net

al.

(2004)

Colo

mbo

etal

.(1

979);

Gokca

yet

al.

(1993);

Johnso

net

al.

(1993);

LeB

aro

net

al.

(2004);

Corl

uka

etal

.(2

009)

Cam

pbel

let

al.

(2000)

Model

2:

Pro

vis

ion

of

info

rmat

ion

and

support

by

LH

Ws

toth

ew

ider

com

munit

y

Lec

hti

get

al.

(1981)

–L

echti

get

al.

(1981)

–L

echti

get

al.

(1981)

–L

echti

get

al.

(1981)

–

Model

3:

Vacc

ine

del

iver

yby

LH

Ws

inth

eco

mm

unit

y

Leh

mann

&Sander

s(2

007)�

––

Leh

mann

&Sander

s(2

007)�

––

––

Model

4:

Vacc

ine

del

iver

yby

LH

Ws

inpri

mary

hea

lth

clin

ics

or

hosp

itals

Lew

inet

al.

(2005)

––

Lew

inet

al.

(2005)

Lew

inet

al.

(2005)

–L

ewin

etal

.(2

005)

–

Model

5:

LH

Wsu

rvei

llan

ceof

imm

unis

ati

on

cover

age

––

––

––

––

The

num

ber

sin

the

table

repre

sent

the

studie

sin

cluded

inth

ere

vie

w.

*In

form

atio

nla

ckin

gfo

rre

fere

nce

(Leh

mann

&Sander

s2007).

�Info

rmati

on

lack

ing

for

studie

s(C

och

rane

Eff

ecti

ve

Pra

ctic

eand

Org

anis

ati

on

of

Care

Gro

up

(EPO

C)

(2009);

Hig

gins

&G

reen

2009;

Leh

mann

&Sander

s2007;

Lew

inet

al.

2010).

�It

isuncl

ear

whet

her

LH

Ws

inre

fere

nce

(Lec

hti

get

al.

1981)

del

iver

edvacc

ines

inth

eco

mm

unit

yor

at

the

clin

ic.

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

ª 2011 Blackwell Publishing Ltd 1051

immunisation coverage, these studies took place in

high-income countries, and it is unclear how transferable

these findings are to other populations. We also have little

knowledge about the effect of using LHWs as part of a larger

team as only two studies used this approach. In addition, a

further review indicated that we know little about the costs

and cost-effectiveness of using lay health workers in immu-

nisation programmes (Corluka et al. 2009).

There is currently a focus globally on the shifting of tasks

from highly qualified health workers to health workers

with shorter training and fewer qualifications in order to

make more efficient use of available human resources

(WHO 2007). The vaccination of children by LHWs is

highly relevant to such initiatives. The development of new

and simple injection technology has also increased the

potential for the safe delivery of vaccines by LHWs

(Quiroga et al. 1998; WHO ⁄ UNICEF 2005). However,

LHWs gave vaccines in only two of the studies and both

studies had serious flaws, making interpretation of their

findings difficult. Further evidence is needed on such

approaches.

A typology of lay health workers for immunisation

We used the studies in this review to develop a typology of

intervention models involving LHWs to improve immuni-

sation uptake. Table 2 describes five intervention models

based on the main tasks undertaken by the LHWs.

Combined with factors relating to delivery characteristics

within the health system (e.g. whether immunisation is

delivered by LHWs alone or as part of a primary healthcare

team) and the characteristics of the LHWs themselves (e.g.,

the form of remuneration received), the typology provides

a framework to facilitate decision-making by policy

makers regarding how LHWs may contribute to improving

immunisation uptake in their setting. Table 2 also sum-

marises where evidence is available from the included

studies for the intervention models and the delivery and

health worker characteristics outlined. The typology could

also be used to standardise the description of LHW

immunisation interventions in the literature, thereby facil-

itating better comparison across programmes in the future

(Winch et al. 2005).

Including non-randomised studies

One of the main motivations of this review was to expand

the evidence base of our Cochrane review (Lewin et al.

2010). It is often suggested that substantial evidence from

non-randomised studies is available and should be included

in effect reviews, and we therefore expected our expansion

of the original inclusion criteria to result in a number of

additional studies. However, only two non-randomised

controlled studies were found. While these studies con-

tributed to our understanding of the range of interventions

that might be implemented, they did not provide significant

additional evidence regarding the effectiveness of LHWs

for vaccination and did not change the Cochrane review

conclusions.

Conclusion

The review shows promising benefits of lay health workers

on child immunisation coverage. We have identified a

number of intervention models for LHWs in this field.

However, for many models, more high-quality studies are

needed, particularly from LMICs.

Acknowledgements

Our thanks to Marit Johansen, Susan Munabi-Babigumira,

Jan Odgaard-Jensen and Andy Oxman for their helpful

feedback and assistance. Thanks also to authors who

provided additional information on the included studies.

Funding for this review was provided by the Research

Council of Norway.

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Supporting Information

Additional Supporting Information may be found in the

online version of this article:

Figure S1. Search strategy.

Figure S2. Characteristics of included studies.

Figure S3. Figure 5: LHW involvement in childhood

immunization (outcome: immunization up-to-date) –

sensitivity analysis for cluster adjustments.

Please note: Wiley-Blackwell are not responsible for the

content or functionality of any supporting materials

supplied by the authors. Any queries (other than missing

material) should be directed to the corresponding author

for the article.

Corresponding Author Claire Glenton, Global Health Unit, Norwegian Knowledge Centre for the Health Services, Boks 7004

St. Olavsplass, N-0130 Oslo, Norway. Tel.: +47 46 400 415 /416 516 58; Fax: +47 23 25 50 10; E-mail: claire.glenton@

kunnskapssenteret.no

Tropical Medicine and International Health volume 16 no 9 pp 1044–1053 september 2011

C. Glenton et al. Can lay health workers increase the uptake of childhood immunisation?

ª 2011 Blackwell Publishing Ltd 1053