Socio-economic status and menarcheal age in urban african schoolgirls in the western cape, South Africa

Abstract

The impact of different socio-economic levels, height, weight and sum of four skinfolds on the menarcheal age of 302 Black, South African school girls ranging in age from 8 to 17 years was researched. Socioeconomic status was obtained by means of a questionnaire that focused on the education, income, and occupations of the parents of the participants and the accommodation in which they were reared. Menarcheal age was obtained by means of a questionnaire. When restricted to those girls who had reached menarche, the mean age was found to be 14.34 years (SD=0.93). The application of survival analysis revealed an estimated median age of 14.25 years with a 95% confidence interval estimate of 14.08 and 14.58. Based on the log-rank statistic, significant differences were found in the survival curves of the different SES categories (p=0.0098). It was found that lower SES corresponded to curves having longer survival times, i.e. later ages of menarche. Differences were found in weight (p=0.037) and in height (p=0.0042), but no difference in SUM4 (p=0.44), between girls who have reached menarche and those who have not.