Development of screening indicators for ranking areas at risk of vitamin A deficiency in Thailand

Abstract

The objective of this study was to develop community based screening indicators for identifying areas at risk of vitamin A deficiency. Three hundred children aged 24-71 months in 12 villages were randomly selected to participate in the study. These villages were located in Songkhla, Yala and Narathiwat provinces, and these areas were known to have various degrees of evidence of vitamin A deficiency. Anthropometric measurements and serum retinol analysis were conducted. Data on dietary intake, illness, and socioeconomic status were obtained by interview with mothers. Subsamples of 120 and 97 children were taken for Modified Relative Dose Response and fecal examination for helminthic infections respectively. Statistics used for data analysis were factor analysis, discriminant analysis and Receiver Operating Characteristic curves. Sensitivity and specificity of the screening indicators were calculated and compared with the rate of vitamin A deficiency classified by >= 15% of children with serum retinol < 0.70 umol/l. Results revealed that the screening indicators could identify areas at risk of vitamin A deficiency with 83.3% efficiency. Data to be used for identifying areas at risk of vitamin A deficiency included home and land ownership for agriculture, dietary intake of vitamin A, access to social services (maternal education and antenatal care), vaccination, infectious diseases (diarrhoea and upper respiratory tract infection with fever) and nutritional status