SECONDARY AMENORRHEA - PREVALENCE AND MEDICAL CONTACT - A CROSS-SECTIONAL STUDY FROM A DANISH COUNTY

Objective To examine the prevalence of secondary amenorrhoea and the patterns of seeking medical advice for secondary amenorrhoea in an unselected population. Design Cross-sectional postal questionnaire study. Setting County of Copenhagen, Denmark. Subjects 3743 women, aged 15-44, selected at random from a Danish county who were asked to provide information on menstrual patterns for the preceding year, 1988. The response rate was 78%. Information from non-responders was obtained via telephone interviews. Results One-year period prevalence of secondary amenorrhoea of more than 3 months duration was 4.6% and was 7-6%, 3.0%, and 3.7% in women aged 15-24, 25-34, and 35-44 respectively. The duration of secondary amenorrhoea was 6 months or less in 75% aged 15-34 years, but longer than 6 months in 55% of those aged 35-44 years. A social gradient was found of the prevalence of secondary amenorrhoea (odds ratio 3.3, 95% CI 1.5-8.3) in the lowest social group compared with the highest social group; controlled by age. Only 39% of women with secondary amenorrhoea had contacted a doctor. Educational level or social status did not seem to influence the frequency of medical contact in women with amenorrhoea. Conclusion Spontaneous return of the menstrual cycle occurs within 6 months in many amenorrheic women below the age of 35. The detailed investigation of secondary amenorrhoea in this age group can be postponed until it is of 6 months duration, unless there is clinical suspicion of disease. The relative infrequency with which women with secondary amenorrhoea seek medical advice constitutes an important source of selection bias in hospital-based clinical research on this topic.