For permission to use where not already granted under a licence please go to http: Abstract Objective To examine sociodemographic and behavioural differences between men who have sex with men MSM participating in recent UK convenience surveys and a national probability sample survey.
Methods We compared MSM aged 18—64 years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles Natsal-3 undertaken in —, with men in the same age range participating in contemporaneous convenience surveys of MSM: Analyses compared men reporting at least one male sexual partner past year on similarly worded questions and multivariable analyses accounted for sociodemographic differences between the surveys.
Partner numbers were higher and same-sex anal sex more common in convenience surveys. Unprotected anal intercourse was more commonly reported in EMIS. Differences between the samples were reduced when restricting analysis to gay-identifying MSM. Convenience surveys recruit larger samples of MSM but tend to over-represent MSM identifying as gay and reporting more sexual risk behaviours. Because both sampling strategies have strengths and weaknesses, methods are needed to triangulate data from probability and convenience surveys.
Lancet HIV in review. However, because the proportion of men having sex with men is relatively low, 1 the sample of MSM in general population surveys like Natsal is small, precluding anything but relatively rudimentary analyses. Nonetheless, Natsal enables assessment of the proportion of MSM who attend gay bars and clubs or use the internet to find a sexual partner, which are potentially useful in assessing the selection biases inherent in convenience surveys of MSM recruited through venues and websites.
Previous research has shown that MSM participating in venue-based convenience surveys were more likely to be younger, report greater sexual risk behaviours and sexually transmitted infection STI diagnoses than MSM who participated in Natsal This study is the first to compare several convenience surveys of MSM in Britain carried out in — with a population probability survey Natsal-3 carried out contemporaneously.
We begin by drawing on Natsal-3 data to calculate the proportion of MSM who use gay venues and seek a sexual partner on the internet. We then compare the three convenience surveys with Natsal-3 to calculate differences in sociodemographic characteristics, drug use, sexual behaviour and sexual health characteristics.
In addition, we investigate the influence of gay identity on the observed differences. Methods This paper compares data from a national probability sample survey, Natsal-3, with data from three surveys that used convenience sampling: To be included in these analyses, research participants were required to have reported at least one male sexual partner in the year prior to data collection, being resident in Britain and being aged 18—64 years.
Our analyses involved comparison between the surveys where questions on sociodemographics, drug use, sexual behaviour and sexual health had similar wordings table 1. Further details of each survey are reported below.