Agreement in Reported Sexual Partnership Dates and Implications for Measuring Concurrency

Objectives: To describe the reliability of reported dates of first and last sexual exposure, as elicited from sexually transmitted disease/ human immunodeficiency virus cases during routine contact investi-gation, and determine their adequacy for assessing concurrency. Methods: We used contact tracing data from 5 studies in which both members of 774 dyads were interviewed and named each other as sex partners. We assessed partners ’ agreement on the dates of first and last exposure as related to precision (to the day, month, or year) of reported dates and demographic and behavioral characteristics of the dyad. We performed simulations that introduced reporting error, based on our observed data, to posited “true ” temporal configurations of partnerships to assess the impact of unreliability in reporting on the measurement of concurrency. Results: Thirty-two percent of dyads agreed on the exact date of first sexual exposure, and 36 % did so for the date of last sexua