SELECTION BIAS IN A STUDY ON HOW WOMEN EXPERIENCED INDUCED-ABORTION

Objective. One third of the women who had an induced abortion at the d epartment of gynecology and obstetrics in Malmo 1989 refused to partic ipate in an interview a year later to explore their experience and the care they had received. Using data from the mandatory preoperative vi sit it was then possible to compare participants with no-participants with regard to socio-demographic characteristics, reproductive history and stared reason for abortion. By continued follow-up of medical rec ords it has furthermore been possible to ascertain how many women conc eived within a year, and how many of them applied for another abortion and how many elected to continue the pregnancy to term. Setting. Depa rtment of Obstetrics and Gynecology, Lund University, University Hospi tal, Malmo, Sweden. This is the sole referral hospital serving the pop ulation of Malmo (approx. 230 000). Subjects. All 1285 women who under went induced abortion at the department in 1989. +Study design. In eac h case information on socio-demographic characteristics, reproductive history and stated reasons for abortion was collected at the mandatory clinical visit prior to the abortion. This information was used for c omparison of participants and non-participants in the planned 1-year f ollow-up interview. Results. Young, unmarried women of low educational status and without full-lime employment or studying were overrepresen ted in the non-participant group. The proportion of women with childre n was however smaller in that group. Within 12 months after the aborti on, 118 women 66 (7.7%) of the participants in the follow-up interview and 52 (12%) of the non-participants conceived again but elected to c ontinue the pregnancy to term (P<0.05), whereas 124 of the women 80 (9 .5%) and 44 (10.2%) of the respective subgroups again applied for abor tion within 12 months. Conclusion. One third of the women who underwen t induced abortion did not wish to be interviewed about their emotiona l and somatic experience of the abortion 1 year later. Non-participati on at the follow-up interview was associated with socio-demographic fa ctors which in studies about other medical problems have been shown to be associated with increased vulnerability and morbidity. Non-partici pation was also associated with an increased childbirth rate during th e following 2 years. The large proportion of non-participants is a mat ter for concern as to some extent it reflects inability of the health care system to establish trustful relationships with these women. How the participants in the follow-up study experienced this relationship will soon be published in our next paper. Support from the women's sur roundings and the adviser the women met at the public health care syst em clearly influenced the women's psychological reactions after the ab ortion [1]. It is therefore important to ascertain to what extent the management of abortion applicants in fact fulfils their individual nee ds and expectations. (C) 1998 Elsevier Science Inland Ltd.