Individual-level sterility: a new method of estimation with application to sub-Saharan Africa.

This paper extends work on measures of population proportions sterile to propose a new estimator of an individual woman's age at sterility and consequently her sterility status at given ages. Accuracy and reliability, examined in a simulation study, appear satisfactory. From World Fertility Survey data for five African countries, the proportions sterile by age estimated by the individual measure and by the population estimator are almost identical. Cameroon and Kenya show substantial variation in prevalence and incidence of sterility across ethnic groups and by number of marriages. Unexpectedly, the evidence suggests that sterility increased from 1960 on in Kenya and remained unchanged in Cameroon.