Estimating the number of men who have sex with men in Ha Noi, Viet Nam by the capture – recapture method
Q. Nguyen1, V. Schoenbach1, T. Bennett2, W. Kalsbeek3, W. Miller1, P. Huynh4, B. Le4, T. Le4
1UNC Gillings School of Global Public Health, Epidemiology, Chapel Hill, United States, 2UNC Gillings School of Global Public Health, Maternal and Child Health, Chapel Hill, United States, 3UNC Gillings School of Global Public Health, Biostatistics, Chapel Hill, United States, 4Institute for Studies of Society, Economy, and Environment, Ha Noi, Viet Nam
Background: Though men who have sex with men (MSM) are recognized as a key population for HIV prevention and surveillance, there is very limited information on the size of this population in different countries. This paper estimates the number of MSM in Ha Noi, Viet Nam.
Methods: The capture-recapture method was used. The first capture was accomplished through a Respondent Driven Sampling (RDS) survey of MSM in Ha Noi from 8 April to 8 October 2008. The second capture was a national online survey of MSM from 29 October 2008 to 31 January 2009.
Results: This estimation procedure was used with MSM age 18 to 39 years. 385 and 355 MSM in Ha Noi participated in the first and second surveys, respectively, including 14 who participated in both surveys. We therefore estimate that there were 9,763 (95%CI: 4,842-14,683) men aged 18-39, or about 1.4% of men in this age bracket, in Ha Noi had sex with other men last year.
Conclusions: This study is the first to estimate the size of an MSM population in Viet Nam. This estimated may be useful for planning HIV programs, though additional studies should be conducted to validate and improve the precision of this estimate.