Vertical integration of general practices with acute hospitals in England: rapid impact evaluation

Background: Vertical integration means merging organisations that operate at different stages along the patient pathway. We focus on acute hospitals running primary care medical practices. Evidence is scarce concerning the impact on use of health-care services and patient experience.

Objectives: To assess the impact of vertical integration on use of hospital services, service delivery and patient experience and whether patients with multiple long-term conditions are affected differently from others.

Design: Rapid, mixed methods evaluation with four work packages: (1) review of NHS trust annual reports and other sources to understand the scale of vertical integration across England; (2) development of the statistical analysis; (3) analysis of national survey data on patient experience, and national data on use of hospital services over the 2 years preceding and following vertical integration, comparing vertically integrated practices with a variety of control practices; and (4) focus groups and interviews with staff and patients across three case study sites to explore the impact of vertical integration on patient experience of care.

Results: At 31 March 2021, 26 NHS trusts were in vertically integrated organisations, running 85 general practices across 116 practice sites. The earliest vertical integration between trusts and general practices was in 2015; a mean of 3.3 practices run by each trust (range 1–12). On average, integrated practices have fewer patients, are slightly more likely to be in the most deprived decile of areas, are more likely to hold an alternative provider medical services contract and have worse Quality and Outcomes Framework scores compared with non-integrated practices.

Vertical integration is associated with statistically significant, modest reductions in rates of accident and emergency department attendances: 2% reduction (incidence rate ratio 0.98, 95% confidence interval 0.96 to 0.99; p < 0.0001); outpatient attendances: 1% reduction (incidence rate ratio 0.99, 95% confidence interval 0.99 to 1.00; p = 0.0061), emergency inpatient admissions: 3% reduction (incidence rate ratio 0.97, 95% confidence interval 0.95 to 0.99; p = 0.0062) and emergency readmissions: 5% reduction (incidence rate ratio 0.95, 95% confidence interval 0.91 to 1.00; p = 0.039), with no impact on length of stay, overall inpatient admissions or inpatient admissions for ambulatory care sensitive conditions. The falls in accident and emergency department and outpatient attendance rates are temporary. Focus groups and interviews with staff (N = 22) and interviews with patients (N = 14) showed that with vertical integration, health service improvements are introduced following a period of cultural interchange. Patients with multiple long-term conditions continue to encounter ‘navigation work’ choosing and accessing health-care provision, with diminishing continuity of care.

Limitations: In the quantitative analysis, we could not replicate the counterfactual of what would have happened in those specific locations had practices not merged with trusts. There was imbalance across three case study sites with regard to staff and patients recruited for interview, and the latter were drawn from patient participation groups who may not be representative of local populations.

Conclusions: Vertical integration can lead to modest reductions in use of hospital services and has minor or no impact on patient experience of care. Our analysis does not reveal a case for widespread roll-out of the approach.

Future research: Further quantitative follow-up of the longer-term impact of vertical integration on hospital usage and more extensive interviewing of patients and their carers about patient experiences of navigating care.

Funding: This project was funded by the National Institute for Health and Care Research (NIHR) Health and Social Care Delivery Research programme (BRACE Project no. 16/138/31) and will be published in full in Health and Social Care Delivery Research; Vol. 11, No. 17. See the NIHR Journals Library website for further project information.