The effect of provider affiliation with a primary care network on emergency department visits and hospital admissions.

BACKGROUND: Primary care networks are designed to facilitate access to inter-professional, team-based care. We compared health outcomes associated with primary care networks versus conventional primary care.

METHODS: We obtained data on all adult residents of Alberta who visited a primary care physician during fiscal years 2008 and 2009 and classified them as affiliated with a primary care network or not, based on the physician most involved in their care. The primary outcome was an emergency department visit or nonelective hospital admission for a Patient Medical Home indicator condition (asthma, chronic obstructive pulmonary disease, heart failure, coronary disease, hypertension and diabetes) within 12 months.

RESULTS: Adults receiving care within a primary care network ( n = 1 502 916) were older and had higher comorbidity burdens than those receiving conventional primary care ( n = 1 109 941). Patients in a primary care network were less likely to visit the emergency department for an indicator condition (1.4% v. 1.7%, mean 0.031 v. 0.035 per patient, adjusted risk ratio [RR] 0.98, 95% confidence interval [CI] 0.96-0.99) or for any cause (25.5% v. 30.5%, mean 0.55 v. 0.72 per patient, adjusted RR 0.93, 95% CI 0.93-0.94), but were more likely to be admitted to hospital for an indicator condition (0.6% v. 0.6%, mean 0.018 v. 0.017 per patient, adjusted RR 1.07, 95% CI 1.03-1.11) or all-cause (9.3% v. 9.1%, mean 0.25 v. 0.23 per patient, adjusted RR 1.08, 95% CI 1.07-1.09). Patients in a primary care network had 169 fewer all-cause emergency department visits and 86 fewer days in hospital (owing to shorter lengths of stay) per 1000 patient-years.

INTERPRETATION: Care within a primary care network was associated with fewer emergency department visits and fewer hospital days.