Table 3.

Risk factors and corresponding risk scores for HIV-1 acquisition among 753 MSM in Kilifi, Kenya, 2005–2016.

Characteristics	Risk score model IRR (95% CI)	P value	Risk score model Coefficient	Risk scorea
Age categories (years)
18–24	4.0 (1.2–13.6)	.024	1.40	1
25–34	2.7 (0.8–9.1)	.113	0.99	-
35+	Reference		Reference
Sex of partner in past 3 months
Both men and women	Reference		Reference
Men only	2.2 (1.3–3.7)	.002	0.80	1
Sexual exposure and protection with condoms in past week
No activity	Reference		Reference
All protected	1.2 (0.7–2.2)	.566	0.18	-
Any unprotected	2.6 (1.5–4.4)	<.001	0.95	1
Receptive anal intercourse (RAI) in past 3 months
No	Reference		Reference
Yes	4.3 (2.2–8.5)	<.001	1.45	1
Group sex in past 3 months
No	Reference		Reference
Yes	1.9 (1.1–3.3)	.014	0.67	1

CI, confidence interval; IRR, incidence rate ratio.

^aCoefficient from the risk score model rounded to the nearest integer.