Table 3. Cancer risk associated with digoxin use in heart failure patients in Taiwan.

Variable	HF Patient with Digoxin			HF Patient with Non-Digoxin			Hazard ratio and 95% CI
	Cases	PY	Incidence	Cases	PY	Incidence	CHRa	AHRb
Age (years)
<45	5	689.4	0.73	26	3408.8	0.76	Ref.	Ref.
45–64	46	3170	1.45	147	10973.8	1.34	1.83(1.25–2.67)*	1.69(1.16–2.48)*
≥65	148	6593.9	2.24	307	13790	2.23	3.13(2.17–4.50)**	2.61(1.80–3.80)**
Gender
Female	110	5585.6	1.97	230	16078	1.43	Ref.	Ref.
Male	89	4867.7	1.83	250	12094.6	2.07	1.29(1.11–1.50)**	1.27(1.09–1.48)*
Incomes (US$)
≥1281(≥ NT$ 40,000)	6	443.6	1.35	23	1582.8	1.45	Ref.	Ref.
640–1280 (NT$ 20,000–39,999)	11	865.4	1.27	46	3380.9	1.36	0.94(0.60–1.47)	0.87(0.56–1.37)
<640 (< NT$ 20,000)	182	9144.3	1.99	411	23208.9	1.77	1.32(0.91–1.91)	1.00(0.68–1.48)
Region
Northern	77	3831	2.01	211	11659.6	1.81	Ref.	Ref.
Center	65	3432.6	1.89	115	7718.5	1.49	0.86(0.72–1.04)	0.81(0.67–0.99)*
South	49	2752.5	1.78	143	7803.4	1.83	0.98(0.82–1.17)	0.91(0.75–1.10)
East	8	437.2	1.83	11	991.1	1.11	0.71(0.45–1.14)	0.71(0.45–1.14)
Urbanization
Urban	100	5109	1.96	243	14668.1	1.66	Ref.	Ref.
Suburban	71	3957	1.79	179	10320	1.73	1.01(0.86–1.19)	0.96(0.81–1.14)
Rural	28	1387.3	2.02	58	3184.5	1.82	1.09(0.86–1.38)	1.08(0.85–1.37)
CCI
<3	36	3063	1.18	105	10470.7	1.00	Ref.	Ref.
≥3	163	7390.3	2.21	375	17701.9	2.12	2.13(1.77–2.57)**	1.86(1.54–2.25)**
All	199	10453.3	1.90	480	28172.6	1.70	1.16(0.98–1.37)	1.04(0.88–1.23)

PY, person-years at risk per 100 person-years, HF, Heart Failure

a. CHR: Crude hazard ratio was calculated by using stratified Cox proportional hazards regression

b. AHR (adjusted hazard ratio): Controlling the variables of age, gender, income, region, urbanization, cci, *: p<0.05 **: p<0.001