Table 2.

Model summary for chemsex associated substances use among MSM

Substance	Study	Substance use	Total sample size	Prevalence	Pooled effect (95%CI)	τ	Notes
Cocaine	(Ko et al., 2012)	12	1645	0.01 (0.00, 0.01)	0.01 (0.00, 0.03)	0.01	In the past 6 months
	(Lim et al., 2015)	15	1235	0.01 (0.01, 0.02)			In the past 6 months
	(Sapsirisavat et al., 2016)	3	499	0.01 (0.00, 0.01)			Categorised to rare/regular
	(Sze et al., 2020)	29	569	0.05 (0.03, 0.07)			In the past 6 months
	(Z. Wang et al., 2020)	0	88	0.01 (0.00, 0.01)			In the past year
	(Yang et al., 2016)	1	205	0.00 (0.00, 0.01)			MSMLHIV
GHB/GBL	(Ko et al., 2012)	33	1645	0.02 (0.01, 0.03)	0.15 (0.03, 0.27)	0.15	In the past 6 months
	(Lim et al., 2015)	34	1235	0.03 (0.02,0.04)			In the past 6 months
	(Sze et al., 2020)	200	569	0.35 (0.31, 0.39)			In the past 6 months
	(Tan et al., 2021)	27	570	0.05 (0.03, 0.06)			-
	(Z. Wang et al., 2020)	29	88	0.33 (0.23, 0.43)			in the past year
	(Wu et al., 2019)	10	79	0.13 (0.05, 0.20)			MSMLHIV
Ketamine	(Ko et al., 2012)	204	1645	0.12 (0.11, 0.14)	0.08 (0.04,0.12)	0.05	In the past 6 months
	(Lim et al., 2015)	76	1235	0.06 (0.05, 0.07)			In the past 6 months
	(Nemoto et al., 2012)	22	112	0.20 (0.12, 0.27)			Kathoey
	(Sze et al., 2020)	63	569	0.11 (0.08, 0.14)			In the past 6 months
	(N. T. Vu et al., 2017)	8	622	0.01 (0.00, 0.02)			-
	(Z. Wang et al., 2020)	2	88	0.02 (−0.01, 0.05)			In the past year
	(Wu et al., 2019)	6	79	0.08 (0.02, 0.13)			MSMLHIV
	(Yang et al., 2016)	12	205	0.06 (0.03, 0.09)			MSMLHIV
Methamphet amine	(Duong et al., 2018)	15	45	0.33 (0.20, 0.47)	0.16 (0.09, 0.22)	0.13	-
	(Han et al., 2020)	16	48	0.33 (0.20, 0.47)			MSMLHIV
	(Hidaka et al., 2014)	211	5731	0.04 (0.03, 0.04)			-
	(Ko et al., 2012)	25	1645	0.02 (0.01, 0.02)			In the past 6 months
	(Lim et al., 2015)	87	1235	0.07 (0.06, 0.08)			In the past 6 months
	(Nishijima et al., 2013)	57	973	0.06 (0.04, 0.07)			History of illicit drug use among HIV positive samples
	(Piyaraj et al., 2018)	128	1372	0.09 (0.08, 0.11)			-
	(Sapsirisavat et al., 2016)	18	499	0.04 (0.02, 0.05)			Categorised to rare/regular
	(Sze et al., 2020)	222	569	0.39 (0.35, 0.43)			In the past 6 months
	(Tan et al., 2021)	27	570	0.05 (0.03, 0.06)			-
	(N. T. Vu et al., 2017; N. T. T. Vu et al., 2017)	89	622	0.14 (0.12, 0.17)			-
	(Z. Wang et al., 2020)	32	88	0.36 (0.26, 0.46)			In the past year
	(Wansom et al., 2020)	98	563	0.17 (0.14, 0.21)			MSMLHIV
	(Wu et al., 2019)	21	79	0.27 (0.17, 0,36)			MSMLHIV
	(Yang et al., 2016)	26	205	0.13 (0.08, 0.17)			MSMLHIV

Notes: - refers to information not applicable. 95% CI = 95% confident interval. MSMLHIV = men have sex with men living with HIV. The scale on the effects is prevalence.