Abstract & Overview
Context: Studies identified prevalence of vitamin A deficiency among Indian preschool-aged children. Aims: The meta-analysis was conducted on peer-reviewed articles published between 1960 and 2007. Settings and Design: Thirteen epidemiologic studies were identified from 250 potentially relevant articles. Material and methods: Studies were selected on, Firstly; a broad criterion of vitamin A deficiency among Indian preschool-aged children was developed on information provided in the WHO publication. Secondly, 'Night Blindness (XN)' among preschool-age children along with Corneal Xerosis associated with Bitot's spot (X1B) was considered as positive clinical signs. Finally, in absence of universally accepted criteria of reporting of prevalence, weighted average data was considered as positive cases irrespective of criteria of diagnosis. Statistical analysis used: Median and inter-quartile range was used. Results: Wide differences in samples and primary outcome variables in these studies were observed. After adjusting for these confounding characteristics, consistent patterns of vitamin A deficiency among Indian preschool-aged children was calculated. The total number of children in this study population was 208379 [with median=1094 and IQR = 283.0 - 8978.0] and the number of children suffering from Vitamin A deficiency disorders was 12510 [with median =80 and IQR = 36.5 - 201.0]. The median prevalence was 7.0% and Inter-Quartile Range (IQR) = 3.3% - 9.3%. Though the study period varied between 1960 and 2005, the median study period was found to be 1999 [with IQR = 1981.5-2004.5]. Conclusion: Wide inter-regional variation in these studies on the prevalence was possibly because of the non-uniform adherence to the diagnostic criteria.