A simple method to evaluate the massive dose vitamin A prophylaxis program in preschool children

Abstract

A massive dose vitamin A prophylaxis program is currently in operation in several States of India. Evaluation of this program on a large scale has so far been difficult due to lack of baseline data on the prevalence of vitamin A deficiency in children. In this study, a simple evaluation method which makes use of the linear relationship that exists between age on one hand and prevalence of ocular signs of vitamin A deficiency (Bitot’s spots) on the other is described. Regression coefficients between age and prevalence of vitamin A deficiency of areas not covered by the program (control areas) were found to be significantly different both from zero and from regression coefficients of regularly covered areas (experimental areas). Also, all regression lines of control areas were found to be above the regression zone of experimental areas. These differences between the experimental and control areas which were significant, indicate the impact of the program in areas where the program is in operation. The regression coefficient calculated for one area where the program was discontinued after some time was found to be significantly different from zero, also it was different from the regression zone of the experimental areas. However, the regression coefficient of the discontinued area was found to be significantly different from the experimental areas only at 10% level, indicating a lesser degree of efficiency of the program in this area as compared to regularly fed areas. It is, therefore, suggested that evaluation of the massive dose prophylaxis program be done against the null hypothesis β = 0.0065--the regression coefficient achievable under field conditions.