Table 1 Characteristics of studies included in the meta-analysis
Study | Year | Country | The definition of UAI | Sample size | Prevalence of UAI among MSM recruited online | Prevalence of UAI among MSM recruited offline |
|---|---|---|---|---|---|---|
Ross et al. [30] | 2000 | Sweden | Never used condom during AI with casual partners in the last year | MSM (overall), n = 1,351 | 9.8% (62/635) | 7.5% (54/716) |
Rhodes et al. [40] | 2002 | United States | Inconsistent condom use during AI in the last year | MSM (overall), n = 498 | 34.0% (165/382) | 41.4% (51/116) |
Elford et al. [28] | 2004 | United Kingdom | UAI with serodiscordant or HIV-unknown male partner in the last 3 months | HIV-neg MSM, n = 1,254 | 26.9% (183/680) | 18.6% (107/574) |
|  |  |  | UAI with serodiscordant or HIV-unknown male partner in the last 3 months | HIV-pos MSM, n = 273 | 47.2% (67/142) | 42.0% (55/131) |
|  |  |  | UAI with male partner in the last 2 months | HIV-unk MSM, n = 570 | 35.6% (141/396) | 19.0% (33/174) |
Knapp et al. [29] | 2004 | United States | UAI in the last 2Â months | MSM (overall), 551 | 23.8% (73/307) | 19.7% (48/244) |
Bolding et al. [31] | 2005 | United Kingdom | UAI with casual serodiscordant or HIV- unknown male partner in the last 3 months | HIV-neg MSM, n = 1,048 | 23.8% (75/315) | 16.0% (117/733) |
|  |  |  | UAI with casual serodiscordant or HIV- unknown male partner in the last 3 months | HIV-pos MSM, n = 661 | 43.3% (29/67) | 18.0% (107/594) |
|  |  |  | UAI with any casual male partner in the last 3 months | HIV-unk MSM, n = 291 | 20.3% (40/197) | 5.3% (5/94) |
Hospers et al. [26] | 2005 | Netherlands | UAI with casual partner in the last 6 months | MSM (overall), n = 6,185 | 23.0% (1,146/4,981) | 21.0% (253/1,204) |
Evans et al. [23] | 2007 | United Kingdom | UAI in the last 3 months | MSM (overall), n = 2,182 | 45.0% (929/2,065) | 36.6% (43/117) |
Xing et al. [7] | 2008 | Chinese | UAI with male partner in the last anal sex | MSM (overall), n = 269 | 58.1% (36/62) | 34.8% (72/207) |
Fernández-Dávila et al. [27] | 2009 | Spain | UAI in the last 3 months | MSM (overall), n = 2,044 | 31.0% (384/1,240) | 27.0% (217/804) |
Tsui et al. [1] | 2010 | Chinese | Engaged in any MSM UAI in the last year | MSM (overall), n = 566 | 53.1% (120/226) | 33.8% (115/340) |
Raymond et al. [41] | 2010 | United States | UAI | MSM (overall), n = 2,297 | 37.1% (268/455) | 42.2% (664/910) |
Liu et al. [39] | 2011 | Chinese | UAI in the last 3 months | MSM (overall), n = 2,692 | 59.9% (1,434/2,393) | 64.9% (194/299) |
Grov C. [42] | 2012 | United States | UAI in the last 3 months | MSM (overall), n = 477 | 28.2% (43/152) | 20.9% (68/325) |
Sanchez et al. [43] | 2012 | United States | UAI with most recent casual male sex partner in the last year | MSM (overall), n = 5,224 | 29.3% (766/2,617) | 19.1% (497/2,607) |