Measuring concurrency: an empirical study of different methods in a large population-based survey and evaluation of the UNAIDS guidelines

Glynn, J. R., Dube, A., Kayuni, N., Floyd, S., Molesworth, A., Parrott, F., French, N. and Crampin, A. C. (2012) Measuring concurrency: an empirical study of different methods in a large population-based survey and evaluation of the UNAIDS guidelines. AIDS, 26(8), pp. 977-985. (doi: 10.1097/qad.0b013e328350fc1f) (PMID:22555149)

Abstract

Background: Recent UNAIDS guidelines recommend measuring concurrency 6 months before the interview date, based on overlapping partnership dates. This has theoretical advantages, but little is known about how well it can be measured in practice. Methods: The assumptions underlying the UNAIDS measure were tested using data from a sexual behaviour survey conducted in rural northern Malawi. All resident adults aged 15–59 were eligible. Questions included self-reported concurrency and dates for all marital and nonmarital partnerships in the past 12 months. Results: A total of 6796 women and 5253 men were interviewed, 83 and 72% of those eligible, respectively. Since few women reported multiple partners, detailed analysis was restricted to men. Overall 19.2% [95% confidence interval (CI) 18.1–20.2] of men self-reported concurrent relationships in the past year (almost all of those with more than one partner). Using overlapping dates the estimate was 16.7% (15.7–17.7). Excluding partnerships which tied on dates (making overlap uncertain) or restricting the analysis to the three most recent partners gave similar results. The UNAIDS 6-month measure was 12.0% (11.1–12.9), and current concurrency was 11.5% (10.6–12.4). The difference between dates-based and self-reported 12-month measures was much larger for unmarried men: 11.1% (9.7–12.4) self-reported; 7.1% (6.9–8.2) on dates. Polygyny (15% of married men) and the longer duration of relationships stabilized the estimates for married men. Nonmarital partnerships were under-reported, particularly those starting longer ago. Conclusions: The difficulties of recall of dates for relationships, and under-reporting of partners lead to underestimation of concurrency using date-based measures. Self-reported concurrency is much easier to measure and appears more complete.

• Item Type: Articles
• Additional Information: Source of funding: The Wellcome Trust.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Crampin, Professor Mia and Parrott, Miss Fiona
• Authors: Glynn, J. R., Dube, A., Kayuni, N., Floyd, S., Molesworth, A., Parrott, F., French, N., and Crampin, A. C.
• College/School: College of Medical Veterinary and Life Sciences > School of Health & Wellbeing > Public Health
• Journal Name: AIDS
• Publisher: Lippincott, Williams and Wilkins
• ISSN: 0269-9370
• ISSN (Online): 1473-5571