LB13 Measuring Concurrent Sexual Partnerships in Behavioural Surveys: A Tale of Two Methods

Tuesday, June 10, 2014
Exhibit Hall
Catherine Mercer, BSc, MSc, PhD1, Sarah Burkill, MSc2, Soazig Clifton, BSc3, Nigel Field, MB PhD3, Clare Tanton, PhD3, Catherine Aicken, BSc, MSc4, Pam Sonnenberg, MB BCh, MSc, PhD5 and Anne Johnson, MBBS, MD3, 1Centre for Sexual Health & HIV Research, Research Department of Infection & Population Health, University College London, London WC1E 6JB, United Kingdom, 2University College London, London, United Kingdom, 3Research Department of Infection and Population Health, University College London, London, United Kingdom, 4Research Department of Infection & Population Health, Centre for Sexual Health & HIV Research, London, United Kingdom, 5Department of Infection and Population Health, University College London, London, United Kingdom

Background:  Concurrency data are important for understanding STI transmission in populations. However, as a socially-sensitive behaviour, some studies measure concurrency by examining whether the dates of recent partnerships overlap, rather than asking a direct question. This paper compares these 2 methods in terms of: (i) the prevalence of concurrency; (ii) the extent of discrepancy and associated demographic and behavioural factors; and (iii) their association with reporting STI diagnosis/es.

Methods:  Complex survey analyses of probability sample data collected from 15,162 men and women aged 16-74y resident in Britain 2010-2012 using computer-assisted personal-interviewing, including computer-assisted self-interview for the more sensitive questions, including the dates of participants’ (max.) 3 most recent partners (MRPs), a direct question about concurrency, and STI diagnosis/es (timeframe for these variables: past 5 years).

Results:  Among participants reporting 2+ partners in the past 5 years (2,828 men; 3,202 women), the proportion of men reporting concurrency at the direct question was similar to that estimated from MRP dates (40.6% vs. 40.0%); but differed among women: 31.0% vs. 38.2%, respectively. The direct question resulted in less missing data than using the MRP dates (0.0% vs. 8.7% among men; 0.1% vs. 7.9% among women). A discrepancy between the measures existed for one-third of men and women, and increased with increasing partner numbers but few other factors. In logistic regression, the direct question was more strongly associated with reporting STI diagnosis/es than using MRP dates: odds ratios adjusted for age and partner numbers: 2.20 (95% CI:1.54-3.15) vs. 1.63 (95%CI:1.17-2.28) among men; 2.26 (95%CI:1.71-2.98) vs. 1.60 (95%CI:1.21-2.12) among women.

Conclusions:  Similar levels of concurrency were observed for the two measures, at least for men, although within-individual discrepancy between the measures was common. Behavioural surveys should use a direct question as this requires fewer assumptions, yields fewer missing data, and better predicts reported STI diagnosis/es.