Does social disadvantage affect the validity of self-report for cervical cancer screening?

Aisha K Lofters,^1–3 Rahim Moineddin,^1,4,5 Stephen W Hwang,^3,6 Richard H Glazier<sup>1–3,4,5

1</sup>Department of Family and Community Medicine, University of Toronto, Toronto, ²Department of Family and Community Medicine, St Michael's Hospital, Toronto, ³Centre for Research on Inner City Health, The Keenan Research Centre in the Li Ka Shing Knowledge Institute of St Michael's Hospital, Toronto, ⁴Institute for Clinical Evaluative Sciences, Toronto, ⁵Dalla Lana School of Public Health, University of Toronto, Toronto, ⁶Department of Medicine, University of Toronto, Toronto, ON, Canada

Objective: The aim was to review the international literature on the validity of self-report of cervical cancer screening, specifically of studies that made direct comparisons among women with and without social disadvantage, based on race/ethnicity, foreign-born status, language ability, income, or education.
Method: The databases of Medline, EBM Reviews, and CINAHL from 1990 to 2011 were searched using relevant search terms. Articles eligible for data extraction documented the prevalence of cervical cancer screening based on both self-report and an objective measure for women both with and without at least one measure of social disadvantage. The report-to-record ratio, the ratio of the proportion of study subjects who report at least one screening test within a particular time frame to the proportion of study subjects who have a record of the same test within that time frame, was calculated for each subgroup.
Results: Five studies met the extraction criteria. Subgroups were based on race/ethnicity, education, and income. In all studies, and across all subgroups, report-to-record ratios were greater than one, indicative of pervasive over-reporting.
Conclusion: The findings suggest that objective measures should be used by policymakers, researchers, and public-health practitioners in place of self-report to accurately determine cervical cancer screening rates.

Keywords: vulnerable populations, early detection of cancer, vaginal smears, Pap test, reproducibility of results, validity