Age at menarche in Sri Lankan Tamil girls in Jaffna.

Using the status-quo method and Probit analysis, the median age at menarche of Sri Lankan Tamil girls (N = 333) from a middle socio-economic group was estimated as 13.78 +/- 0.07 years with a standard deviation of 1.01 years. This is about one year later than the median for the urban and about six months earlier than the median for the rural girls of Sri Lanka of the 1950s. However, this median age estimate agrees well with the results of an urban Madras sample. The reliability of the present finding is discussed.