title: Low numeracy predicts reduced accuracy of retrospective reports of frequency of sexual behavior.
abstract: Assessment of the frequency of sexual behavior relies on participants' ability to arithmetically aggregate information over time and across partners. This study examines the effect of numeracy (arithmetic skills) on the accuracy of retrospective reports of sexual behavior. For 91 days, the participants completed daily reports about their sexual activity. Participants then completed a survey on sexual behavior over the same period. The discrepancies between the survey-based and the diary-based measures of frequency of vaginal and anal intercourse were evaluated. Multiple regression analysis showed that the discrepancy between retrospective and diary measurements of sexual intercourse increased with lower numeracy (P = 0.026), lower education (P = 0.001), aggregate question format compared to partner-by-partner format (P = 0.031) and higher frequency of intercourse occasions (P < 0.001). Lower numeracy led to a 1.5-fold increase (adjusted mean = 14.1-20.9) in the discrepancy for those using the aggregate question format and a 2.0-fold increase (adjusted mean = 3.7-7.6) for those using the partner-by-partner format.
authors.affiliation: Department of Psychiatry and Behavioral Medicine, Medical College of Wisconsin, Center for AIDS Intervention Research, Milwaukee, WI 53202, USA. mcauliff@mcw.edu
authors.forename: Timothy L
authors.initials: TL
authors.lastname: McAuliffe
authors.forename: Wayne
authors.initials: W
authors.lastname: DiFranceisco
authors.forename: Barbara R
authors.initials: BR
authors.lastname: Reed
mesh_terms: D000328:Adult; D000368:Aged; D001294:Attitude to Health; D003625:Data Collection / Q000706:statistics & numerical data*; D004522:Educational Status; D005260:Female; D015658:HIV Infections / Q000517:prevention & control; D006801:Humans; D007182:Income; D008297:Male; D008433:Mathematics; D008875:Middle Aged; D011446:Prospective Studies; D012044:Regression Analysis; D012189:Retrospective Studies; D012307:Risk Factors; D012309:Risk-Taking; D057566:Self Report; D012725:Sexual Behavior / Q000523:psychology / Q000706:statistics & numerical data*; D012747:Sexual Partners; D011795:Surveys and Questionnaires; D055815:Young Adult