Table 3. Cause-specific hazard ratio of cervical cancer from age 61 to age 80 comparing women screened and unscreened at age 61–65, by screening history at age 51–60, based on Cox regression model.

Screening history at age 51–60	Unadjusted model			Adjusted for birth cohort and education
	HR (95% CI)a	P value	P value for PH testb	HR (95% CI)a	P value	P value for PH testb
Adequately screened, normal	0.92 (0.71–1.20)	0.53	0.27	0.90 (0.69–1.17)	0.42	0.34
Inadequately screened, normal	0.87 (0.60–1.28)	0.49	0.48	0.82 (0.56–1.22)	0.33	0.33
Unscreened	0.38 (0.22–0.66)	<0.01	0.62	0.42 (0.24–0.72)	<0.01	0.28
Low-grade abnormality	0.40 (0.24–0.70)	<0.01	0.41	0.43 (0.25–0.74)	<0.01	0.59
High-grade abnormality	0.58 (0.36–0.94)	0.03	0.23	0.59 (0.36–0.96)	0.04	0.15

^aHazard ratio and 95% confidence interval of cervical cancer among women screened at age 61–65 in relation to women unscreened at age 61–65.

^bProportional hazard testing based on Schoenfeld residual test.