Validation of Vitamin A Supplementation Coverage Using Post-event Coverage Surveys in 11 Sub-Saharan African Countries

Abstract

Objectives: Twice-yearly child health days (CHDs) have had remarkable success reaching children twice-yearly with life-saving interventions, including vitamin A supplementation (VAS). In 2012, over 80% of targeted children in Sub-Saharan Africa received VAS according to tally-sheet data. All countries implementing CHDs use tally-sheet data to measure coverage; however, coverage measured from tally-sheets is prone to errors due to inaccurate census data, incorrect tallying and mathematical errors totaling coverage across districts and regions. Methods: To validate coverage reported by tally-sheets, Helen Keller International implemented Post-Event Coverage Surveys (PECS) using a 30x30 cluster design and standard WHO EPI cluster sampling methodology in 11 countries in sub-Saharan Africa. For each survey, 900 caretakers of children 6-59 months were interviewed within six weeks of CHDs to reduce recall bias. Results: Thirty-five post event coverage surveys were conducted between January 2010 and July 2013. PECS coverage was lower than administrative coverage in 33/35 (94%) of cases. PECS and administrative coverage data were within a 5% margin of difference in 5 cases (14%), and within >5-10% in 8 cases (23%). However, in 11 cases (31%), results differed by >10-20%, and in 11 cases (31%), results differed by 21-82%. Conclusions: PEC surveys indicate considerable over-reporting of coverage by tally-sheets and provide critical data that is essential to evaluate and improve VAS distribution during CHDs. The continued use of PEC surveys is recommended in areas where tally-sheet data has not been confirmed or has been shown to be unreliable.