Article Text

Download PDFPDF

Original article
Men who have sex with men in Great Britain: comparing methods and estimates from probability and convenience sample surveys
  1. Philip Prah1,
  2. Ford Hickson2,
  3. Chris Bonell3,
  4. Lisa M McDaid4,
  5. Anne M Johnson1,
  6. Sonali Wayal1,
  7. Soazig Clifton1,
  8. Pam Sonnenberg1,
  9. Anthony Nardone5,
  10. Bob Erens1,6,
  11. Andrew J Copas1,
  12. Julie Riddell4,
  13. Peter Weatherburn7,
  14. Catherine H Mercer1
  1. 1Research Department of Infection & Population Health, University College London, London, UK
  2. 2Sigma Research, London School of Hygiene & Tropical Medicine, London, UK
  3. 3UCL Institute of Education, London, UK
  4. 4MRC/CSO Social & Public Health Sciences Unit, University of Glasgow, Glasgow, UK
  5. 5HIV/STI Department, Public Health England, London, UK
  6. 6Department of Health Services Research and Policy, London School of Hygiene & Tropical Medicine, London, UK
  7. 7Department of Social & Environmental Health Research, London School of Hygiene & Tropical Medicine, London, UK
  1. Correspondence to Philip Prah, UCL Research Department of Infection & Population Health, 3rd floor, Mortimer Market Centre, off Capper Street, London WC1E 6JB, UK; Philip.prah{at}


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 148 MSM aged 18–64 years interviewed for Britain's third National Survey of Sexual Attitudes and Lifestyles (Natsal-3) undertaken in 2010–2012, with men in the same age range participating in contemporaneous convenience surveys of MSM: 15 500 British resident men in the European MSM Internet Survey (EMIS); 797 in the London Gay Men's Sexual Health Survey; and 1234 in Scotland's Gay Men's Sexual Health Survey. 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.

Results MSM in convenience surveys were younger and better educated than MSM in Natsal-3, and a larger proportion identified as gay (85%–95% vs 62%). Partner numbers were higher and same-sex anal sex more common in convenience surveys. Unprotected anal intercourse was more commonly reported in EMIS. Compared with Natsal-3, MSM in convenience surveys were more likely to report gonorrhoea diagnoses and HIV testing (both past year). Differences between the samples were reduced when restricting analysis to gay-identifying MSM.

Conclusions National probability surveys better reflect the population of MSM but are limited by their smaller samples of 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.


This is an Open Access article distributed in accordance with the terms of the Creative Commons Attribution (CC BY 4.0) license, which permits others to distribute, remix, adapt and build upon this work, for commercial use, provided the original work is properly cited. See:

View Full Text

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.