Accuracy of Self-Reported Screening Receipt Among Women with Intellectual Disabilities
Women with intellectual disabilities receive cervical and breast cancer screenings at markedly lower rates than their nondisabled peers, despite the proven effectiveness of both screenings in reducing women’s cancer mortality. However, existing research has relied on self- or caregiver-reported screening data, and it is unclear if self-reported data are accurate. Previous research indicates nondisabled women over-report the receipt screenings or underestimate the time since their last screening. However, self-reported medical information is useful, easier, and less expensive to obtain than other methods. The aim of this study was to determine the accuracy of self-report by women with intellectual disabilities.
This study was part of a larger randomized control trial of an intervention to increase cervical and breast cancer screening. Women with intellectual disabilities (n=174) were enrolled from 29 counties across one southeastern state, aged >18 years, and able to participate in brief in-person interviews. Guardians’ consent was obtained as necessary. Women and often their caregivers were asked to identify all health care providers from 2006-2010. Medical practices were then faxed project information, data abstraction forms, and signed HIPAA consent forms. Practices were asked to complete the abstraction forms and fax back to a secure fax. Women participated in brief in-person interviews to obtain their knowledge of cervical and breast cancer screening, using an instrument developed and normed for adults with intellectual disabilities. Women were asked if they had ever received a Pap test or mammogram, and if yes, when their last exam was completed.
Univariate descriptive analyses, Chi-square tests, and the Kappa statistic were employed. Women’s baseline interview data was compared to medical record data from the physician to determine the accuracy of the women’s self-report. If the women’s self-report matched with their medical records data, it was coded as correct, and if the women’s self-report did not match with their medical records data, it was coded as incorrect.
72% of the women accurately reported their receipt or non-receipt of Pap tests. 86% of women accurately reported receipt or non-receipt of mammogram. These results were statistically significant. We then examined frequency and rates of accuracy. Among women in the study, 58% accurately reported the timing of their last Pap test and 51% of women accurately reported the timing of their last mammogram. Estimates for accurate Pap test recall by nondisabled women range from 65% to 89% and from 65% to 97% for mammography.
Researchers studying receipt of cervical and breast cancer screening for this population should feel confident using self-reported data if they would like to measure lifetime receipt. However, other sources of data are likely needed to determine timing of receipt from these women.