Sample Attrition in Studies of Psychosocial Sequelae of Abortion: How Great a Problem?¹

This study examines sample attrition problems in abortion research and the implications for conclusions reached about psychosocial sequelae of abortion. A review of 17 recent studies shows that the percent of the initial sample lost to follow‐up ranges from a low of 13% to a high of 86%. Younger women and Catholic women appear to be less likely to participate in follow‐up. Since both of these characteristics are associated with a greater likelihood of negative sequelae, follow‐up studies may be underestimating the extent of negative reaction to abortion. Data from a recent study are presented; comparisons are made between characteristics of initial volunteers and the total population and between the volunteers who return for the follow‐up interview and those who do not. Results support the suggestion that women for whom the abortion was more stressful are less likely to be represented in the final sample. Factors affecting the likelihood of participating in research are explored and strategies for improving the representativeness of samples are suggested.