TABLE 2.

Association Between Contraceptive Copayment and Nonadherence to the Contraceptive Pill, Patch, or Ring by Year of Initiation, Kaiser Permanente Northern California, 2011–2014

	2011/2012	2013/2014
	aHR (95% CI)	aHR (95% CI)
Copayment
No ($0)	REF.	REF.
Yes (>$0)	0.98 (0.94, 1.03)	1.09 (1.04, 1.14)
Age (y)
19–24	REF.	REF.
25–29	1.08 (1.05, 1.17)	1.20 (1.15, 1.26)
Race/ethnicity
Non-Hispanic white	REF.	REF.
Non-Hispanic black	1.40 (1.32, 1.48)	1.40 (1.30, 1.50)
Hispanic	1.19 (1.15, 1.24)	1.26 (1.20, 1.33)
Asian	1.13 (1.08, 1.18)	1.13 (1.07, 1.19)
Other/unknown	1.10 (1.03, 1.17)	1.06 (0.98, 1.14)
Low-income census tract
Yes	1.07 (1.02, 1.12)	1.11 (1.04, 1.17)
No	REF.	REF.
Abortion in the past 12 mo
Yes	1.14 (1.05, 1.24)	1.31 (1.17, 1.46)
No	REF.	REF.

aHR indicates adjusted hazard ratio; CI, confidence interval; REF., reference.