Background: Immunization coverage remains low, particularly in low- and middle-income countries (LMIC), despite its proven effectiveness in reducing the burden of childhood infectious diseases. A Cochrane review has shown that patient reminder recall is effective in improving coverage of immunization but technologies to support this strategy are lacking in LMIC.
Objectives: To evaluate the effectiveness of intervention strategies to boost and sustain high childhood immunization coverage in LMIC.
Search strategy: We searched the following databases for primary studies: Cochrane Central Register of Controlled Trials (CENTRAL) 2010, Issue 1, part of The Cochrane Library. www.thecochranelibrary.com, including the Cochrane Effective Practice and Organisation of Care (EPOC) Group Specialised Register (searched 8 July 2010); MEDLINE, Ovid (1948 to March Week 3 2011) (searched 30 March 2011); EMBASE, Ovid (1980 to 2010 Week 26) (searched 8 July 2010); CINAHL, EBSCO (1981 to present ) (searched 8 July 2010); LILACS, VHL (1982 to present) (searched 8 July 2010); Sociological Abstracts, CSA Illumnia (1952 to current) (searched 8 July 2010). Reference lists of all papers and relevant reviews were identified and searched for additional studies.
Selection criteria: Included studies were randomized controlled trials (RCTs), non-randomized controlled trials (NRCTs), and interrupted-time-series (ITS) studies. Study participants were children aged 0 to 4 years, caregivers, and health providers. Interventions included patient and community-oriented interventions, provider-oriented interventions, health system interventions, multi-faceted (any combination of the above categories of interventions), and any other single or multifaceted intervention intended to improve childhood immunisation coverage The primary outcome was the proportion of the target population fully immunized with recommended vaccines by age.
Data collection and analysis: Two authors independently screened full articles of selected studies, extracted data, and assessed study quality.
Main results: Six studies were included in the review; four were at high risk of bias. There was low quality evidence that: facility based health education may improve the uptake of combined vaccine against diphtheria, pertussis, and tetanus (DPT3) coverage (risk ratio (RR) 1.18; 95% CI 1.05 to 1.33); and also that a combination of facility based health education and redesigned immunization cards may improve DPT3 coverage (RR 1.36; 95% CI 1.22 to 1.51). There was also moderate quality evidence that: evidence-based discussions probably improve DPT3 coverage (RR 2.17; 95% CI 1.80 to 2.61), and that information campaigns probably increase uptake of at least a dose of a vaccine (RR 1.43; 95% CI 1.01 to 2.02).
Authors' conclusions: Home visits and health education may improve immunization coverage but the quality of evidence is low.