Impact and sustainability of centralising acute stroke services in English metropolitan areas: retrospective analysis of hospital episode statistics and stroke national audit data

Abstract

Objectives: To investigate whether further centralisation of acute stroke services in Greater Manchester in 2015 was associated with changes in outcomes and whether the effects of centralisation of acute stroke services in London in 2010 were sustained.

Design: Retrospective analyses of patient level data from the Hospital Episode Statistics (HES) database linked to mortality data from the Office for National Statistics, and the Sentinel Stroke National Audit Programme (SSNAP).

Setting: Acute stroke services in Greater Manchester and London, England.

Participants: 509 182 stroke patients in HES living in urban areas admitted between January 2008 and March 2016; 218 120 stroke patients in SSNAP between April 2013 and March 2016.

Interventions: Hub and spoke models for acute stroke care.

Main outcome measures: Mortality at 90 days after hospital admission; length of acute hospital stay; treatment in a hyperacute stroke unit; 19 evidence based clinical interventions.

Results: In Greater Manchester, borderline evidence suggested that risk adjusted mortality at 90 days declined overall; a significant decline in mortality was seen among patients treated at a hyperacute stroke unit (difference-in-differences -1.8% (95% confidence interval -3.4 to -0.2)), indicating 69 fewer deaths per year. A significant decline was seen in risk adjusted length of acute hospital stay overall (-1.5 (-2.5 to -0.4) days; P<0.01), indicating 6750 fewer bed days a year. The number of patients treated in a hyperacute stroke unit increased from 39% in 2010-12 to 86% in 2015/16. In London, the 90 day mortality rate was sustained (P>0.05), length of hospital stay declined (P<0.01), and more than 90% of patients were treated in a hyperacute stroke unit. Achievement of evidence based clinical interventions generally remained constant or improved in both areas.

Conclusions: Centralised models of acute stroke care, in which all stroke patients receive hyperacute care, can reduce mortality and length of acute hospital stay and improve provision of evidence based clinical interventions. Effects can be sustained over time.

Fig 1

Simplified pre-centralisation and post-centralisation models in London and Greater Manchester. First panel: before 2010 centralisations in London and Greater Manchester. Second panel: after 2010 centralisation in London. Third panel: after 2010 centralisation in Greater Manchester until 2015. Fourth panel: after 2015 centralisation in Greater Manchester. CSC=comprehensive stroke centre; DSC=district stroke centre; HASU=hyperacute stroke unit; PSC=primary stroke centre.

Fig 2

Adjusted trends in mortality at 90 days in London. Note that y axis does not start at zero. Vertical line indicates when centralisation in London was fully operational (July 2010), although centralisation began to be implemented in October 2009. P value (under null hypothesis that regression coefficient for every month after centralisation (which occurred in July 2010) is same as regression coefficient for July 2010) is 0.09

Fig 3

Adjusted trends in length of hospital stay in London. Vertical line indicates when centralisation in London was fully operational (July 2010), although centralisation began to be implemented in October 2009. P value (under null hypothesis that regression coefficient for every month after centralisation (which occurred in July 2010) is same as regression coefficient for July 2010) is <0.01)