Towards an optimal composition of general practitioners and nurse practitioners in out-of-hours primary care teams: a quasi-experimental study

OBJECTIVES: To gain insights into the ability of general practitioners (GPs) and nurse practitioners (NPs) to meet patient demands in out-of-hours primary care by comparing the outcomes of teams with different ratios of practitioners. DESIGN: Quasi-experimental study. SETTING: A GP cooperative (GPC) in the Netherlands. INTERVENTION: Team 2 (1 NP, 3 GPs) and team 3 (2 NPs, 2 GPs) were compared with team 1 (4 GPs). Each team covered 35 weekend days. PARTICIPANTS: All 9503 patients who were scheduled for a consultation at the GPC through a nurse triage system. OUTCOME MEASURES: The primary outcome was the total number of consultations per provider for weekend cover between 10:00 and 18:00 hours. Secondary outcomes concerned the numbers of patients outside the NPs' scope of practice, patient safety, resource use, direct healthcare costs and GPs' performance. RESULTS: The mean number of consultations per shift was lower in teams with NPs (team 1: 93.9, team 3: 87.1; p<0.001). The mean proportion of patients outside NPs' scope of practice per hour was 9.0% (SD 6.7), and the highest value in any hour was 40%. The proportion of patients who did not receive treatment within the targeted time period was higher in teams with NPs (team 2, 5.2%; team 3, 8.3%) compared with GPs only (team 1 3.5%) (p<0.01). Team 3 referred more patients to the emergency department (14.7%) compared with team 1 (12.0%; p=0.028). In teams with NPs, GPs more often treated urgent patients (team 1: 13.2%, team 2: 16.3%, team 3: 21.4%; p<0.01) and patients with digestive complaints (team 1: 11.1%, team 2: 11.8%, team 3: 16.7%; p