“…From the 16 studies that examined condomless anal sex with a partner of unknown/discordant HIV status from 1994 to 2011 (22, 23, 25–29, 35, 37, 39, 42, 44, 51–53, 57), 25 findings were included in the analysis (Figure 4). The results of the multi-level models indicated a significant increase in the behavior over time (overall analysis without knot for the time period 1994–2011: beta = 0.03, p < 0.001; with a knot: 1994–2002, beta = 0.05, p < 0.001; 2003–2011, beta = 0.02, p < 0.001).…”