While much has been learned about the determinants ofcurrent contraceptive use in developing countries over the past 20 years or so, the dynamics of changes in contraceptive status-failure, switching, and abandoning method use-are much less understood. These dynamics are significant because contraceptive effectiveness and duration of use become increasingly important determinants of fertility as desired family size declines and contraceptive prevalence rises. In addition to its demographic impact, the analysis of contraceptive use dynamics
is important because it can inform efforts to improve service delivery in various ways.
The purpose of this report is to examine contraceptive discontinuation in six developing countries that conducted DHS surveys between 1991 and 1995 Bangladesh, Colombia, Egypt, Indonesia, Peru, and Zimbabwe. Four types of discontinuation are examined: failure, switching, and abandonment of use subdivided into users who are not 'in need' of contraception following discontinuation of a method and those who remain 'in need.' The first type of abandonment refers to users who abandon contraception because they no longer need to use, either because they want to get pregnant or because their exposure to the risk of pregnancy is reduced. The second type refers to users who abandon contraception for reasons that leave then 'in need' of resuming use to avoid an unwanted pregnancy, such as side effects, health concerns, husband's disapproval, access/availability, and cost. Analyses are based on monthly contraceptive histories collected from all survey respondents. Following an assessment of data quality, both life table and multivariate statistical techniques are used in the analysis.
The multivariate analyses of the determinants of contraceptive discontinuation, switching, and failure are based on hazards models. In the analysis, each episode of contraceptive use is divided into three-month intervals and piecewise-constant hazards models with random effects are fitted.