A medical record linkage analysis of abortion underreporting

Abstract

Inaccuracy in women's reports of their abortion histories affects many areas of interest to reproductive health professionals and researchers. The identification of characteristics that affect the accuracy of reporting is essential for the improvement of data collection methods. A comparison of the medical records of 104 American women aged 27-30 in 1990-1991 with their self-reported abortion histories revealed that 19% of these women failed to report one or more abortions. Results of logistic regression analysis indicate that nonwhite women were 3.3 times as likely as whites to underreport. With each additional year that had elapsed since the first recorded abortion, women became somewhat more likely to underreport (odds ratio of 1.3), while each additional year of a woman's education slightly decreased the likelihood of underreporting (odds ratio of 0.7).

PIP: Underreporting of abortion, prevalent both between and within populations, threatens to undermine the validity of research in this area. Estimates of abortion, contraceptive failure, miscarriage, and other reproductive history events that rely on self-reports are vulnerable to bias. This study sought to identify the characteristics associated with the likelihood of underreporting an abortion history. 651 respondents from the Child Health and Development Studies who were 27-30 years old in 1990-91 filled out self-administered reproductive health questionnaires; these results were then compared to the women's 1980-92 medical records. The final sample consisted of 104 women with a medical record of a total of 170 abortions. 90% of women who had at least one abortion in their medical record reported at least one abortion; only 56% reported all of their abortions within 1 year of the medical record date, however. Overall, 19% underreported their abortion history. Of these, half reported no abortions and half reported fewer abortions than were in the medical record. Another 46% reported the exact number of abortions, and 35% reported more abortions than were in the record. Non-White women were 3.3 times more likely than Whites to underreport abortion. For each year that elapsed since the procedure, the odds of underreporting increased by 26%. Finally, every additional year of schooling decreased the likelihood of underreporting abortion by 30%.