Table 1

Logistic univariable and multivariable regression analysis of factors associated with STI acquisition among MSM participating in the Amsterdam Cohort Studies between 2009 and 2019

Sexual behaviour factors	Univariable n=971 MSM/13 473 visits			Multivariable n=959 MSM/12 274 visits
Sexual behaviour factors	OR	95% CI	P value	OR	95% CI	P value
Number of insertive casual partners	1.64	1.56 to 1.73	<0.001	1.20	1.12 to 1.30	<0.001
Number of receptive casual partners	1.75	1.67 to 1.84	<0.001	1.33	1.23 to 1.43	<0.001
Condomless insertive sex (yes)	2.82	2.51 to 3.18	<0.001	1.25	1.04 to 1.50	0.02
Condomless receptive sex (yes)	3.29	2.91 to 3.71	<0.001	1.35	1.12 to 1.63	0.001
AI during group sex (yes)	2.19	1.94 to 2.46	<0.001	1.14	0.98 to 1.33	0.08
Chemsex (yes)	2.50	2.21 to 2.83	<0.001	1.61	1.40 to 1.85	<0.001
Steady partnership (no)	1.56	1.39 to 1.75	<0.001	1.37	1.20 to 1.56	<0.001

Continuous variables including partner numbers were log transformed. Visits with one or more missing sexual behaviour factors were excluded from multivariable analysis. STI acquisition is defined as gonorrhoea, chlamydia or syphilis diagnosis at one or more anatomical locations.
Created by the authors.
AI, anal intercourse; ; MSM, men who have sex with men.