Sexual Minority Women in Longitudinal Survey Research: Is Attrition a Problem?

As more longitudinal surveys collect information on sexual orientation, evaluating the quality of these data and understanding how sexual minorities engage with the survey process are increasingly important endeavors. This study constitutes the first systematic analysis of sexual orientation as a predictor of attrition from longitudinal surveys. Drawing upon the minority stress model, we developed testable hypotheses about how sexual identity and sexual identity change relate to panel attrition. These hypotheses were subsequently tested using data from two national cohorts of Australian women from the Australian Longitudinal Study on Women's Health (one born 1973-1978, n = 11,262, and one born 1989-1995, n = 16,689). In the older cohort, sexual minority women were more likely to attrit from the survey than exclusively heterosexual women-largely due to noncontact rather than noncooperation. The associations faded once sociodemographic and health-related covariates were included in the models. Further, higher rates of noncontact were observed among women who changed their sexual identity in a more same-sex-oriented direction, compared to women with a stable sexual identity. None of these associations were apparent in the younger cohort. Taken together, our results suggest that sexual minority status may be a risk factor for panel attrition among older but not younger cohorts of women and that improved efforts to locate and contact participants who are generally vulnerable could increase the retention of sexual minorities in longitudinal studies. Effect sizes were nevertheless small, suggesting that existing research on sexual orientation using longitudinal surveys is unlikely to be biased by non-random attrition of non-heterosexual individuals.