Impact of vertical integration on patients' use of hospital services in England.

BACKGROUND:Debate surrounding the organisation and sustainability of primary care in England highlights the desirability of a more integrated approach to patient care across all settings. One such approach is 'vertical integration', where a provider of specialist care, such as a hospital, also runs general practices. AIM:To quantify the impact of vertical integration on hospital use in England. DESIGN & SETTING:Analysis of activity data for NHS hospitals in England between April 2013 and March 2020. METHOD:Analysis of NHS England data on hospital activity: Accident and Emergency Department (A&E) attendances; outpatient attendances; total inpatient admissions; inpatient admissions for ambulatory care sensitive conditions; emergency admissions; emergency readmissions; length of stay. We compare rates of hospital use by patients of vertically integrated practices and controls, before and after the former were vertically integrated. RESULTS:In the two years after a GP practice changes, for the population registered at that practice, compared with controls, vertical integration is associated modest reductions in rates of A&E attendances (2% reduction [incidence rate ratio (95% CI) of 0.98 (0.96-0.99), P<0.0001]), outpatient attendances (1% reduction [0.99 (0.99-1.00), P=0.0061]), emergency inpatient admissions (3% reduction [0.97 (0.95-0.99), P=0.0062]) and emergency readmissions within 30 days (5% reduction [0.95 (0.91-1.00), P=0.039]), with no impact on length of stay, overall inpatient admissions or inpatient admissions for ambulatory care sensitive conditions. CONCLUSION:Vertical integration is associated with modest reductions in use of some hospital services and no change in others.