Tracking changes in states of contraceptive use over time in sub-Saharan Africa through cohort and period analyses.

It is difficult to gauge the success of programmatic efforts to reduce unmet need for contraception without knowing whether individual women have had their need met and adopted contraception. However, the number of true longitudinal datasets tracking the transition of panels of individual women in and out of states of contraceptive use is limited. This study analyses changes in contraceptive use states using Demographic and Health Survey data for 22 sub-Saharan African countries. A cohort approach, tracking representative samples of five-year age groups longitudinally across surveys, as well as period-based techniques, are applied to indicate whether new users of contraception have been drawn from women who previously had no need and/or those who had unmet need for family planning. The results suggest that a greater proportion of increases in contraceptive use in recent years can be attributed to decreases in the percentage of women with no need, especially among younger women, than to decreases in the proportion with unmet need.