Douching and Genital Talc Use: Patterns of Use and Reliability of Self-reported Exposure

Abstract

Background: Feminine hygiene products contain chemicals that may be harmful to human health. Observational studies of the longterm health effects of such products largely rely on self-reported, recalled exposure. We sought to capture patterns of use over the life course and evaluate the reliability of self-reported data. Methods: We collected retrospective data on douching and genital talc use in the US-based Sister Study at two-time points and evaluated the consistency of reporting. At enrollment (2003)(2004)(2005)(2006)(2007)(2008)(2009), participants were asked to report use in the last year and during ages 10-13. On a follow-up questionnaire (2017-2019), participants were asked about their use of douche or genital talc over their lifetimes. Results: Among 36,202 women who completed both questionnaires, 14% initially reported ever douching and 27% initially reported ever using genital talc. On the follow-up questionnaire, 51% of participants reported ever douching and 32% reported ever using genital talc. Comparisons across the two questionnaires for use in the year before enrollment showed good consistency, with 90% providing the same responses about douching and 87% providing the same responses about genital talc use. Reliability did not vary by cancer status, race and ethnicity, attained education, or age, though there was some evidence of recall bias for genital talc use among ovarian cancer survivors. Conclusions: Classification of ever use of feminine hygiene products may be recalled with good consistency, but agreement was lower for specific time periods and trends may vary by subgroup. These potential differences warrant careful consideration in future studies.

Quantitative recall bias analysis of the talc and ovarian cancer association

“…Scenario 2 assumes 99% sensitivity and specificity for cases' recall, and 82% sensitivity and 99% specificity for controls' recall, which is the amount of misclassification reported by the authors that would nullify the risk estimate. For Scenarios 3 and 4, we used the sensitivity and specificity reported in O'Brien et al [ 13 ] for cases (83 and 87%, respectively, and their respective 95% CIs which were calculated using the EpiR [ 16 ] package in R v4.3.1 [ 17 ]), with 0–5% exposure misreporting among controls in Scenario 3, and 63% sensitivity and 95% specificity and their respective 95% CIs for controls in Scenario 4 (as reported for the whole cohort by O'Brien et al [ 13 ]). For Scenarios 5–7, we assumed the sensitivities and specificities ranged between 90 and 100%, to reflect the potential for lower levels of recall bias that have been reported for other self-reported exposures [ [9] , [10] , [11] , [12] ].…”

“…Recall error rates have been reported in several studies that used self-reported exposures ( e.g. , [ [9] , [10] , [11] , [12] ]), but to the best of our knowledge, only one such study has examined recall of perineal talc use [ 13 ]. O'Brien et al [ 13 ] evaluated data from the Sister Study, a US-based prospective cohort study of women aged 35–74 who had a sister with a history of breast cancer.…”

“…, [ [9] , [10] , [11] , [12] ]), but to the best of our knowledge, only one such study has examined recall of perineal talc use [ 13 ]. O'Brien et al [ 13 ] evaluated data from the Sister Study, a US-based prospective cohort study of women aged 35–74 who had a sister with a history of breast cancer. When examining genital talc use in the 12 months prior to baseline, reporting consistency was 86% (95% CI: 86–87%), with 27% and 21% of participants reporting use when asked at enrollment and at follow-up, respectively.…”

“…When examining genital talc use in the 12 months prior to baseline, reporting consistency was 86% (95% CI: 86–87%), with 27% and 21% of participants reporting use when asked at enrollment and at follow-up, respectively. This corresponds to a recall sensitivity and specificity of 63% (95% CI: 62–64%) and 95% (95% CI: 95–95%), respectively [ 13 ]. Among women with ovarian cancer ( n = 125), the consistency of talc use reporting was 85% (95% CI: 78–91), with 28 and 33% reporting use at enrollment and follow-up, respectively.…”

“…To better understand the potential impact of recall bias on the results of case-control studies of perineal talc use and ovarian cancer, we conducted a quantitative bias analysis using the sensitivity and specificity information reported by O'Brien et al [ 13 ] and previously published case-control data [ 15 ] as a case study.…”