A comparison of trends in stroke care and outcomes between in-hospital and community-onset stroke - The South London Stroke Register.

Background: Stroke care and outcomes have improved significantly over the past decades. It is unclear if patients who had a stroke in hospital (in-hospital stroke, IHS) experienced similar improvements to those who were admitted with stroke (community-onset stroke, COS).

Methods: Data from the South London Stroke Register were analysed to estimate trends in processes of care and outcomes across three cohorts (1995-2001, 2002-2008, 2009-2015). Kaplan-Meier survival curves were calculated for each cohort. Associations between patient location at stroke onset, processes of care, and outcomes were investigated using multiple logistic regression and Cox proportional hazards models.

Results: Of 5,119 patients admitted to hospital and registered between 1995 and 2015, 552(10.8%) had IHS. Brain imaging rates increased from 92.4%(COS) and 78.3%(IHS) in 1995-2001 to 100% for COS and IHS in 2009-2015. Rates of stroke unit admission rose but remained lower for IHS (1995-2001: 32.2%(COS) vs. 12.4%(IHS), 2002-2008: 77.1%(COS) vs. 50.0%(IHS), 2009-2015: 86.3%(COS) vs. 65.4%(IHS)). After adjusting for patient characteristics and case-mix, IHS was independently associated with lower rates of stroke unit admission in each cohort (1995-2001: OR 0.49, 95%CI 0.29-0.82, 2002-2008: 0.29, 0.18-0.45, 2009-2015: 0.22, 0.11-0.43). In 2009-2015, thrombolysis rates were lower for ischaemic IHS (17.8%(COS) vs. 13.8%(IHS)). Despite a decline, in-hospital mortality remained significantly higher after IHS in 2009-2015 (13.7%(COS) vs. 26.7%(IHS)). Five-year mortality rates declined for COS from 58.9%(1995-2001) to 35.2%(2009-2015) and for IHS from 80.8%(1995-2001) to 51.1%(2009-2015). In multivariable analysis, IHS was associated with higher mortality over five years post-stroke in each cohort (1995-2001: HR 1.27, 95%CI 1.03-1.57, 2002-2008: 1.24, 0.99-1.55, 2009-2016: 1.39, 0.95-2.04).

Conclusions: Despite significant improvements for IHS patients similar to those for COS patients, rates of stroke unit admission and thrombolysis remain lower, and short- and long-term outcomes poorer after IHS. Factors preventing IHS patients from entering evidence-based stroke-specific hospital pathways in a timely fashion need further investigation.