Table 3.

Effects of Digoxin on Heart Failure Hospitalization

Patient Subgroups	Absolute Risk % (Events/Total)	Crude HR (97.5% CI)	p Value	Adjusted* HR (97.5% CI)	p Value
< 65 Years (n = 2658)
Placebo (n = 1852)	32%	1	Reference	1	Reference
SDC 0.5–0.9 ng/mL (n = 510)	20%	0.56 (0.45–0.69)	<.0001	0.54 (0.43–0.66)	<.0001
SDC ≥ 1 ng/mL (n = 296)	29%	0.88 (0.70–1.11)	.275	0.70 (0.56–0.88)	.002
≥ 65 Years (n = 2890)
Placebo (n = 2009)	35%	1	Reference	1	Reference
SDC 0.5–0.9 ng/mL (n = 472)	27%	0.66 (0.54–0.79)	<.0001	0.71 (0.58–0.86)	<.0001
SDC ≥ 1 ng/mL (n = 409)	33%	0.75 (0.62–0.91)	.004	0.66 (0.54–0.81)	<.0001

Note: HR = hazard ratio; CI = confidence interval; SDC = serum digoxin concentration.

^*Adjusted for the same covariates as in Table 2.