Table 1.

Study characteristics of 36 samples included in meta-analysis.

Author	Publication year	Location	Study periods	Setting	Sampling method	Survey method	Recall window (months)	QACO score (%)
Tang [55]	2007	Harbin	N/A#	Multiple recruiting methods	Snowball sampling	Interviewer-administered	6	40
Chen [51]	2008	Fuzhou	2008	MSM venue	Multiple sampling methods	Interviewer-administered	6	60
Ouyang et al. [50]	2008	Chongqing	2006	Multiple recruiting methods	Snowball sampling	Interviewer-administered	6	33
Bai and Feng [43]	2010	Liuzhou	2008	Multiple recruiting methods	N/A	Interviewer-administered	6	75
Han et al. [35]	2012	China	2008	N/A	N/A	N/A	6	60
She et al. [34]	2012	4 cites	2008	N/A	Snowball sampling	Interviewer-administered	6	60
Li et al. [48]	2009	Chongqing	2006	MSM venue	Snowball sampling	Interviewer-administered	6	40
Zhang et al. [31]	2012	Wuhan	N/A	MSM venue	Stratified cluster sampling	Interviewer-administered	6	80
Ruan et al. [47]	2009	Jinan	2008	N/A	RDS##	Interviewer-administered	6	60
Chow et al. [29]	2013	Changsha,Tianjin	2011	MSM venue	Convenience sampling	Interviewer-administered	6	75
Cai et al. [24]	2014	Shenzhen	2010	Community-based	RDS	CASI∗	6	80
Liao et al. [41]	2011	4 cities in Shandong Province	2008-2009	Multiple recruiting methods	Multiple sampling methods	Interviewer-administered	6	80
Wang et al. [52]	2007	Harbin	2006	MSM venue	N/A	Interviewer-administered	6	60
Ruan et al. [53]	2007	Beijing	2005	N/A	Multiple sampling methods	Interviewer-administered	6	80
Xu et al. [44]	2010	Liaoning	2006	Recruiting by NGO∗∗	N/A	Interviewer-administered	12	60
Lau et al. [49]	2008	Kunming	2003–2005	Multiple recruiting methods	Convenience sampling	Interviewer-administered	6	60
Cao et al. [37]	2012	4 cities	2008	Recruiting by NGO	Snowball sampling	Interviewer-administered	6	80
Liao et al. [22]	2014	4 cities in Shandong Province	2011	Multiple recruiting methods	N/A	Interviewer-administered	6	70
Tao et al. [28]	2013	Beijing	2010-2011	Multiple recruiting methods	Multiple sampling methods	Interviewer-administered	12	60
Wu et al. [15]	2013	61 cities	2008-2009	N/A	RDS + Snowball sampling	Interviewer-administered	6	90
Guo et al. [36]	2012	Beijing	2009	Multiple recruiting methods	N/A	Self-administered	6	70
Wang et al. [33]	2012	Harbin	2006–2010	Community-based	Snowball sampling	Self-administered	12	65
Cao et al. [30]	2013	Nanchang	2011	Multiple recruiting methods	Multiple sampling methods	Interviewer-administered	1 week	60
Li et al. [56]	2014	Beijing	2009–2011	N/A	RDS	CASI	12	80
Feng et al. [46]	2010	Chengdu	N/A	Multiple recruiting methods	Snowball sampling	Interviewer-administered	6	50
Wang et al. [27]	2013	Beijing	2008-2009	Multiple recruiting methods	Multiple sampling methods	Interviewer-administered	6	80
Zhang et al. [32]	2012	Chongqing	2009	N/A	RDS	CASI	6	80
Zhang et al. [25]	2013	Harbin	2011	Recruiting by NGO	N/A	Interviewer-administered	12	60
Cai et al. [23]	2014	Shenzhen	2009–2012	N/A	Snowball sampling + RDS	Interviewer-administered	6	75
Liu et al. [40]	2011	Beijing	N/A	MSM venue	Snowball sampling	Interviewer-administered	12	50
Wang et al. [26]	2013	Mianyang	2011-2012	N/A	Snowball sampling	Interviewer-administered	6	55
Qu et al. [39]	2011	Inner Mongolia	2010	Community-based	Snowball sampling	Interviewer-administered	6	60
Xu et al. [45]	2010	4 cities	N/A	N/A	Snowball sampling + RDS	Interviewer-administered	6	70
Xi [38]	2011	Hangzhou	2009-2010	MSM venue	Snowball sampling	Interviewer-administered	6	50
Chen et al. [42]	2011	Lanzhou	2006–2010	MSM venue	Snowball sampling	Interviewer-administered	6	50
Li [54]	2007	Beijing	2005	Multiple recruiting methods	Multiple sampling methods	Interviewer-administered	6	70

^#N/A: not available, ^##RDS: respondent-driven sampling, ^∗CASI: computer-assisted self-administered interview, and ^∗∗NGO: Non-Governmental Organizations.