Serosorting and HIV/STI Infection among HIV-Negative MSM and Transgender People: A Systematic Review and Meta-Analysis to Inform WHO Guidelines

Table 1

Study descriptions and key findings.

Study	Population	Findings
Golden et al., 2008 [7]	HIV-negative; MSM^1 in Seattle, USA; 8,314 participants	HIV incidence (among men who tested HIV negative in past year); (i) Condom use (only protected anal intercourse): 28/1827 clinic visits (1.5%); (ii) Serosorting (UAI^2 with HIV negative only): 40/1526 clinic visits (2.6%); (iii) No condom use (nonconcordant UAI): 49/1386 clinic visits (3.5%)
	Age: HIV men: <24: 19%; 25–29: 20%; 30–34: 16%; 35–39: 17%; >40: 28%	STI incidence (Bacterial STI^3: urethral or rectal gonorrhea or chlamydia or early syphilis); (i) Condom use: 601/3859 clinic visits (16%); (ii) Serosorting: 738/3201 clinic visits (23%); (iii) No condom use: 831/3088 clinic visits (27%)
Jin et al., 2009 [3]	HIV-negative; MSM in Sydney, Australia	HIV incidence (median followup 3–9 years); (i) Condom use (only protected anal intercourse; data received from authors for only consistent condom users); serosorting (UAI with HIV negative only); no condom use (UAI with some unknown or any HIV positive)
	1427 participants; Median age: 35 (range: 18–75)	(ii) Serosorting versus condom use: hazard ratio 2.56; 95% CI^4 (0.84–7.78); (iii) Serosorting versus no condom use: hazard ratio 0.31; 95% CI (0.16–0.59)
Marks et al., 2010 [8]	HIV-negative; black and Latino MSM in New York, LA, and Philadelphia, USA; 724 participants; Age not reported	HIV incidence (testing positive during study among those reporting a previous HIV-negative test, most within past year); (i) Condom use (only protected anal intercourse); serosorting (UAI with HIV negative only); No condom use (UAI not limited to HIV negative partners); (ii) Serosorting versus condom use: unadjusted odds ratio 1.68; 95% CI (0.65–4.32); (iii) No condom use versus serosorting: unadjusted odds ratio 2·81; 95% CI (1.30–6.05); adjusted* odds ratio 2.54; 95% CI (1.14–5.68); ∗Adjusted for number of UAI partners of any serostatus, age, education, and employment status
Philip et al., 2010 [9]	HIV-negative; MSM in six cities in the EXPLORE study, USA; 4295 participants in EXPLORE study; 2623 participants used for serosorting analyses; Age: <30: 42%; 31–39: 39%; >40:  20%	HIV incidence; (i) One-unit increase in the natural log serosorting score (odds of condom use with HIV-positive/unknown partners divided by odds of condom use with HIV negative partners): odds ratio 0.88; 95% CI (0.81–0.95); ∗Adjusted for race/ethnicity, numbers of sexual partners, self-report of sexually transmitted infections, methamphetamine and heavy alcohol use, depression, and use of drug and alcohol during sex

1MSM: men who have sex with men.
2UAI: unprotected anal intercourse.
3STI: sexually transmitted infection.
4CI: confidence interval.