Aims: Studies of heart failure (HF) incidence and prevalence frequently rely on hospitalization to identify patients. Our objective was to describe the incidence, prevalence, or outcomes for HF patients diagnosed in the outpatient or emergency department (ED) setting.
Methods and results: In a population-based study of 82,323 HF patients in a single-payer health-care system in Alberta, Canada from 1999 to 2007, we examined trends over time and clinical outcomes. Heart failure patients were first diagnosed in a general outpatient clinic (45.7%), a specialty outpatient clinic (4.0%), the ED (13.7%), or in hospital (36.6%). From years 2000 to 2006, the age-standardized incidence (per 100 000 population) decreased from 538 to 403, whereas the overall prevalence increased from 1585 to 2510. One-year mortality was significantly different among patients first diagnosed in a general outpatient clinic (6.6%), a specialty outpatient clinic (7.5%), ED (19.1%), and hospital (29.8%). Patients initially diagnosed at the time of hospitalization had the fewest median days alive and out of hospital [347, inter-quartile range (IQR): 136-363] over the next year compared with patients in the ED (354, IQR 313-365), specialty outpatient clinic (365, IQR 355-365), and general outpatient clinics (365, IQR: 359-365, P < 0.0001). Patients in the ED had the highest rate of subsequent ED visits, and all-cause, cardiovascular, or HF hospitalization.
Conclusions: Over time, more patients were diagnosed as outpatients compared with a hospital setting. The trends observed in incidence, prevalence, and outcomes for patients with HF differ substantially depending on the location of initial diagnosis. Additionally, efforts to study patients with HF in the ED should be a priority.