Table 3

Mediating effect of CAI and rectal bleeding on rectal douching and HIV infection in Chinese MSM

	X−M		M−Y		X−Y		(X, M)−Y
	aOR (95% CI)	P value	aOR (95% CI)	P value	aOR (95% CI)	P value	aOR (95% CI)	P value
Outcome: HIV infection (Y)
Rectal douching in the past 6 months (X)	1.3 (1.0 to 1.6)	0.038	N/A		1.9 (1.0 to 3.4)	0.038	1.8 (1.0 to 3.2)	0.061
CAI in the past 6 months (M1)	N/A		2.3 (1.3 to 4.3)	0.007	N/A		2.2 (1.2 to 4.1)	0.010
Rectal douching in the past 6 months (X)	2.0 (1.6 to 2.6)	<0.001	N/A		1.9 (1.0 to 3.4)	0.038	1.7 (0.9 to 3.1)	0.089
Rectal bleeding in the past 6 months (M₂)	N/A		2.0 (1.1 to 3.7)	0.020	N/A		1.9 (1.0 to 3.4)	0.044

The Baron and Kenny approach was used to analyse the mediating effect of CAI and rectal bleeding. Multivariate logistic regression models were controlled for age, monthly income and occupation.
aOR, adjusted OR; CAI, condomless anal intercourse; M, mediator; MSM, men who have sex with men; N/A, not applicable; X, exposure variable; Y, outcome variable.