This report concerns some 600 women who had either remained active cases in Jamaican family planning clinics or had dropped out. Women more likely to drop out were single (vs. married or common law union), either very young or very old, with few or large number of living children, who never had a miscarriage, and whose last pregnancy was not a recent one. Religion, social class variables (on clients and partners), and type of contraceptive method failed to differentiate active cases from drop-outs. An The past decade has seen the creation of national family planning programs in many countries. While not all of these programs have explicitly stated their aims, presumably they are trying to achieve one or more of the following goals: reduction of the birth rate by reducing the average family size or the mean fertility of women in their reproductive years, spacing of children, and preventing unwanted children after desired family size has been achieved. These programs face at least three types of problems. First, the target population of "at risk" women has to be identified in terms of their numbers and their demographic and social characteristics. Second, the at risk population must be motivated to enroll in the family planning program. Thirdly, those who have been admitted to the program must be maintained successfully on their contraceptive regimen.Like many other social programs, family planning has been difficult to evaluate and a variety of approaches have been used. The earliest method was to examine program "effort" or "input" and to obtain a count of: the number of new clinics opened, the number of new personnel trained, and the number of new admissions to the program's clinics. These variables are thought to reflect "continuity of service"' and "accomplishment."2 However, determination of the extent of "effort" is of limited usefulness unless one also knows something about the extent of the problem to which the effort is directed and about some of the consequences of this effort.More systematic approaches to evaluation give an explicit recognition to one or more of the three problems listed above. For example, a number of studies have been concerned with defining the characteristics of women who may be counted as being in need of contraception and as being at risk of unwanted conception.1"3-8 Estimates can then be made of the size of the population at risk in specific segments of the society, such as the poor, or for specific areas served by a family planning program. Moreover, by subtracting the proportion of people served by the program, it is possible to calculate one index of program effectiveness, the proportional reduction in the population at risk.However, the proportional reduction in the population at risk via enrollment in the family planning program is only an indirect indication of the program's success and, ultimately, one should also be able to demonstrate an average reduction in the fertility of women in the reproductive age groups. Reductions in fertility attributed to family planning pr...