Table 4.

Time-dependent Cox regression analysis on cumulative prescription period and dosage of thiopurines among thiopurine users^†.

	HR (95% CI)‡	p value
Cumulative Prescription Period (years)
<2	Reference
2–5	1.16 (0.92–1.46)	0.19
>5	1.64 (1.32–2.04)	<0.001
Cumulative Dosage §
<500 DDD	Reference
500–1500 DDD	1.38 (1.15–1.65)	<0.001
>1500 DDD	1.50 (1.18–1.91)	0.001

^†19 individuals were not included in the analysis since prescription records have unclear treatment duration.

^‡adjusted for age, sex, use of concomitant immunosuppressants.

^§DDD = 150 mg azathioprine.

CI, confidence interval; DDD, daily defined dosage; HR, hazard ratio.