Background: Conventional composite outcomes in heart failure (HF) trials, for example, time to cardiovascular death or first HF hospitalization, have recognized limitations. We propose an alternative outcome, days alive and out of hospital (DAOH), which incorporates mortality and all hospitalizations into a single measure. A refinement, the patient journey, also uses functional status (New York Heart Association [NYHA] class) measured during follow-up. The CHARM program is used to illustrate the methodology.
Methods: CHARM randomized 7,599 patients with symptomatic HF to placebo or candesartan, with median follow-up of 38 months. We related DAOH and percent DAOH (ie, percentage of time spent alive and out of hospital) to treatment using linear regression adjusting for follow-up time.
Results: Mean increase in DAOH for patients on candesartan versus placebo was 24.1 days (95% CI 9.8-38.3 days, P < .001). The corresponding mean increase in percent DAOH was 2.0% (95% CI 0.8%-3.1%, P < .001). These findings were dominated by reduced mortality (23 days) but enhanced by reduced time in hospital (1 day). Percent time spent in hospital because of HF was reduced by 0.10% (95% CI 0.04%-0.14%, P < .001). The patient journey analysis showed that patients in the candesartan group spent more follow-up time in NYHA classes I and II and less in NYHA class IV.
Conclusions: Days alive and out of hospital, especially percent DAOH, provide a valuable tool for summarizing the overall absolute treatment effect on mortality and morbidity. In future HF trials, percent DAOH can provide a useful alternative perspective on the effects of treatment.
Trial registration: ClinicalTrials.gov NCT00634400.
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