Protocol for a systematic review of the effects of interventions to inform or educate caregivers about childhood vaccination in low and middle-income countries

Introduction: Despite their proven effectiveness in reducing childhood infectious diseases, the uptake of vaccines remains suboptimal in low and middle-income countries. Identifying strategies for transmitting accurate vaccine information to caregivers would boost childhood vaccination coverage in these countries. The purpose of this review is to assess the effects on childhood vaccination coverage of interventions for informing or educating caregivers about the importance of vaccines in low and middle-income countries, as defined by the World Bank. Methods and analysis: Eligible study designs include randomised controlled trials (RCTs) as well as non-randomised controlled trials (non-RCTs). We will conduct a comprehensive search of both peer-reviewed and grey literature available up to 31 May 2015. We will search PubMed, Scopus, Cochrane Central Register of Controlled Trials, Web of Science, Cumulative Index of Nursing and Allied Health, prospective trial registries and reference lists of relevant publications. Two authors will independently screen the search output, retrieve full texts of potentially eligible studies and assess the latter against predefined inclusion criteria. Disagreements between the two authors will be resolved through consensus and arbitration by a third author. We will pool data from studies with homogenous interventions and outcomes, using random-effects meta-analysis. We will assess statistical heterogeneity using the chi(2) test of homogeneity (with significance defined at the 10% alpha-level) and quantify it using Higgins' inconsistency index. We will explore the cause of any observed statistical heterogeneity using subgroup analysis, with subgroups defined by study design (RCTs vs non-RCTs) and type of intervention (information vs educational interventions). Ethics and dissemination: The proposed systematic review will collect and analyse secondary data that are not associated with individuals. The review will make a significant contribution to the knowledge base of interventions for improving childhood vaccination coverage in low and middle-income countries.