Table 2.

Characteristics associated with initiation of direct-acting antiviral agents for HCV infection among adults aged ≥18 (n = 14 790), Kaiser Permanente Northern California, October 2014–December 2016

Characteristics	Initiation of Direct-Acting Antiviral Agents, Unadjusted RR (95% CI)	P Value	Initiation of Direct-Acting Antiviral Agents, Adjusted RRa (95% CI)	P Valueb
Age, y
18-49	1.00 [Reference]		1.00 [Reference]
50-59	1.1 (1.0-1.2)	.04	1.0 (0.9-1.1)	.93
60-69	1.1 (1.0-1.2)	.006	1.0 (0.9-1.1)	.55
≥70	0.6 (0.5-0.6)	<.001	0.6 (0.5-0.6)	<.001
Sex
Male	1.00 [Reference]		1.00 [Reference]
Female	1.0 (0.9-1.0)	.15	1.0 (0.9-1.0)	.08
Race/ethnicity
Non-Hispanic white	1.00 [Reference]		1.00 [Reference]
Non-Hispanic black	0.7 (0.7-0.8)	<.001	0.7 (0.7-0.8)	<.001
Hispanic	0.8 (0.8-0.9)	<.001	0.8 (0.7-0.9)	<.001
Asian	1.0 (0.9-1.2)	.35	1.1 (1.0-1.2)	.21
Non-Hispanic other/unknown	0.9 (0.8-1.0)	.037	0.9 (0.8-1.0)	.02
Neighborhood deprivation index quartilec
1	1.00 [Reference]		1.00 [Reference]
2	0.9 (0.8-0.9)	<.001	0.9 (0.8-1.0)	.005
3	0.8 (0.7-0.8)	<.001	0.9 (0.8-0.9)	<.001
4	0.7 (0.6-0.7)	<.001	0.8 (0.7-0.8)	<.001
Insurance type
Private	1.00 [Reference]		1.00 [Reference]
Medicare	0.7 (0.7-0.8)	<.001	0.8 (0.8-0.9)	<.001
Medicaid	0.6 (0.6-0.7)	<.001	0.7 (0.6-0.8)	<.001
Annual maximum out-of-pocket health care costs >$3000 (reference: ≤$3000)	0.8 (0.8-0.9)	<.001	0.9 (0.8-0.9)	<.001
No. of alcoholic drinks per week
0	1.00 [Reference]		1.00 [Reference]
1-7	0.9 (0.8-0.9)	<.001	0.8 (0.8-0.9)	<.001
8-14	0.8 (0.7-0.9)	<.001	0.8 (0.6-0.9)	<.001
≥15	0.6 (0.5-0.7)	<.001	0.6 (0.5-0.8)	<.001
Drug abuse diagnosis	0.7 (0.7-0.8)	<.001	0.8 (0.7-0.8)	<.001
Smoking	0.7 (0.7-0.7)	<.001	0.8 (0.7-0.9)	<.001
HCV genotype 1	1.5 (1.4-1.6)	<.001	1.5 (1.4-1.6)	<.001
Advanced liver fibrosis	1.3 (1.2-1.4)	<.001	1.3 (1.3-1.4)	<.001
Never treated for HCV	0.5 (0.5-0.5)	<.001	0.7 (0.6-0.7)	<.001
HIV infection	1.4 (1.2-1.6)	<.001	1.2 (1.1-1.4)	.007
Hepatitis B virus infection	1.0 (0.9-1.1)	.48	0.9 (0.8-1.0)	.07

Abbreviations: HCV, hepatitis C virus; RR, rate ratio.

^a Adjusted RRs were obtained from a Poisson model including age, sex, race/ethnicity, neighborhood deprivation index, HCV genotype, time-updated liver fibrosis, previous HCV treatment, alcohol use, drug abuse diagnosis, smoking, HIV infection, and hepatitis B virus infection.

^b P values were obtained from Pearson's χ² test, with P < .05 considered significant.

^c The neighborhood deprivation index is a measure of socioeconomic status that incorporates census tract–level measures of education, income and poverty, employment, housing, and occupation.²⁰ The highest quartile (4) indicates the greatest neighborhood deprivation and the lowest quartile (1) indicates the lowest neighborhood deprivation.