Disclosure of sexual orientation and behavior in the Nurses' Health Study II: Results from a pilot study

Objective: To examine disclosure of sexual orientation and response rates in a pilot study of questions on sexual orientation and gender of sexual partners in the Nurses' Health Study II. Methods: A pilot questionnaire was mailed to random samples of 350 women from each of three marital status strata: never married, previously married, and currently married. We estimated prevalence of each category of sexual orientation in the pilot study. Response rates to the sexual orientation question for the pilot questionnaire and the 1995 cohort questionnaire were compared. Results: The overall response rate to the pilot study was 78%. In the pilot study, 98% of women reported a sexual orientation of heterosexual, 0.1% bisexual, and 0.9% lesbian, with 0.7% either declining to answer, leaving the question blank, or categorizing themselves as none of the above, weighted for stratified sampling by marital status. The distribution of sexual orientation in the cohort study (N=91,654) was similar. Asking women to participate in the pilot study of sexual orientation questions did not appear to cause participants to drop out of the cohort. Concordance between reported sexual orientation on the pilot study and the cohort study was high. Conclusions: Based on our experience, researchers may be encouraged to add questions on sexual orientation to large studies of women.