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

Abstract

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.

Figure 1:

Association between affiliation with a primary care network and health care utilization (emergency department visits or hospital admissions) for Patient Medical Home indicator conditions as the most responsible diagnosis. Comorbidity adjustment was for the Charlson Comorbidity Index score. Note: CAD = coronary artery disease, COPD = chronic obstructive pulmonary disease, DM = diabetes mellitus, HF = heart failure, HTN = hypertension, PMH = Patient Medical Home indicator conditions.