Impact of vertical integration on patients' use of hospital services in England: an analysis of activity data

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.

To quantify the impact of vertical integration on hospital use in England.

Analysis of activity data for NHS hospitals in England between April 2013 and February 2020.

Analysis of NHS England data on hospital activity, which looked at the following seven outcome measures: accident and emergency (A&E) department attendances; outpatient attendances; total inpatient admissions; inpatient admissions for ambulatory care sensitive conditions; emergency admissions; emergency readmissions; and length of stay. Rates of hospital use by patients of vertically integrated practices and controls were compared, before and after the former were vertically integrated.

In the 2 years after a GP practice changes, for the population registered at that practice, compared with controls, vertical integration is associated with modest reductions in rates of A&E attendances (2% reduction [incidence rate ratio {IRR} 0.98, 95% confidence interval {CI} = 0.96 to 0.99, P<0.0001]), outpatient attendances (1% reduction [IRR 0.99, 95% CI = 0.99 to 1.00, P = 0.0061]), emergency inpatient admissions (3% reduction [IRR 0.97, 95% CI = 0.95 to 0.99, P = 0.0062]), and emergency readmissions within 30 days (5% reduction [IRR 0.95, 95% CI = 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.

Vertical integration is associated with modest reductions in use of some hospital services and no change in others.