Table 3. Cox proportional hazards regression analysis of time to HIV testing among sexual contacts of HIV-positive index clients in Siaya County, Kenya.

Time to Testing	Univariable		Multivariable (Main Model)		Multivariable (Time-Varying Covariate)*
	HR (95% CI)	P value	aHR (95% CI)	P value	aHR (95% CI)	P value
Age, years§
18–24	1.32 (1.15–1.51)	<0.001	1.32 (1.01–1.73)	0.04	0.94 (0.87–1.02)	0.153
25–34	1.14 (1.04–1.24)	0.005	1.18 (1.01–1.39)	0.038	0.96 (0.9–1.01)	0.126
35–44	Ref		Ref		Ref
≥45	1.03 (0.89–1.18)	0.727	0.96 (0.79–1.18)	0.727	1.02 (0.95–1.11)	0.54
Sex
Female	1.10 (1–1.2)	0.04	0.95 (0.81–1.1)	0.496	-	-
Male	Ref		Ref
Marital Status§^
Married Monogamous	Ref		Ref		Ref
Married Polygamous	0.93 (0.73–1.17)	0.527	0.78 (0.54–1.12)	0.174	1.12 (1.01–1.25)	0.039
Single	1.58 (1.25–2)	<0.001	0.71 (0.51–1)	0.05	1.17 (1.08–1.27)	<0.001
Unknown	1.18 (0.98–1.41)	0.079	0.43 (0.3–0.64)	<0.001	1.25 (1.14–1.38)	<0.001
Widowed	1.18 (0.77–1.81)	0.456	0.71 (0.29–1.74)	0.459	1.08 (0.82–1.42)	0.588
Relationship to Index Client§^
Non-spouse Sexual Contact	1.68 (1.44–1.96)	<0.001	1.12 (0.84–1.48)	0.444	1.23 (1.15–1.32)	<0.001
Spouse	Ref		Ref		Ref
Sub-County§
Alego Usonga	1.49 (1.07–2.08)	0.019	1.90 (1.14–3.17)	0.014	0.90 (0.77–1.05)	0.186
Bondo	1.42 (1.02–1.97)	0.037	1.47 (0.92–2.35)	0.11	0.95 (0.82–1.09)	0.449
Gem	1.28 (0.98–1.67)	0.067	1.06 (0.73–1.54)	0.755	1.09 (0.93–1.28)	0.27
Rarieda	1.65 (1.24–2.18)	0.001	1.39 (0.9–2.15)	0.14	1.07 (0.91–1.25)	0.425
Ugenya	Ref		Ref		Ref
Ugunja	1.15 (0.82–1.61)	0.417	0.71 (0.4–1.26)	0.242	1.20 (1.01–1.42)	0.038

*Time-varying covariate interacted with natural logarithm of time

^§Violated proportional hazards assumptions and was included as a time-varying covariate in Cox model

^{^}Significant time-varying covariate interaction

Abbreviations: HR, hazards ratio; CI, confidence interval; aHR, adjusted hazards ratio.