Use of questionnaires in a study of spontaneous abortion in a general population.

STUDY OBJECTIVE The aim was to evaluate the appropriateness of postal questionnaires in studies of spontaneous abortion in a general population. DESIGN Survey of spontaneous abortions by comparing diagnoses reported in questionnaires to information collected from hospital records and a discharge register. SETTING The study took place in the general community. PARTICIPANTS The study involved a random sample of 1400 women born between 1935 and 1960, living in two towns in the south west of Sweden. MEASUREMENTS AND MAIN RESULTS 9% of spontaneous abortions among respondents were not reported in the questionnaire, and 31% were missing in the register; 80% of the spontaneous abortions reported in the questionnaire could be verified in hospital records, and a further 7% were mentioned in the records but not certified by a doctor; 97% of the diagnoses received by the women who had answered affirmatively to two complementary questions on spontaneous abortions could be found in the records. CONCLUSIONS Postal questionnaires can be used in epidemiological studies of spontaneous abortions, among a general population as well as among occupational groups.