VITAMIN-A SUPPLEMENTATION AND CHILD-MORTALITY - A METAANALYSIS

Objective.-A two-part meta-analysis of studies examining the relationship of v Data Sources.-We identified studies by searching the MEDLARS database from 1966 through 1992 and by scanning Current Contents and bibliographies of pertinent articles. Study Selection.-All 12 vitamin A controlled trials with data on mortality identified in the search were used in the analysis. Data Extraction.-Data were independently extracted by two investigators who also assessed the quality of each study using a previously described method. Data Synthesis.-We formally tested for heterogeneity across studies. We pooled studies using the Mantel-Haenszel and the DerSimonian and Laird methods and adjusted for the effect of cluster assignment of treatment groups in community-based studies. Vitamin A supplementation to hospitalized measles patients was highly protective against mortality (DerSimonian and Laird odds ratio, 0.39; 95% confidence interval, 0.22 to 0.66; P=.0004) (part 1 of the meta-analysis). Supplementation was also protective against overall mortality in community-based studies (DerSimonian and Laird odds ratio, 0.70; clustering-adjusted 95% confidence interval, 0.56 to 0.87; P=.001) (part 2 of the meta-analysis). Conclusions.-Vitamin A supplements are associated with a significant reduction in mortality when given periodically to children at the community level. Factors that affect the bioavailability of large doses of vitamin A need to be studied further. Vitamin A supplements should be given to all measles patients in developing countries whether or not they have symptoms of vitamin A deficiency.