In a study published in BMJ Safety and Quality, we evaluated mortality differences between weekend and weekday emergency stroke admissions in England over time. We aimed to determine whether a reconfiguration of stroke services in Greater London was associated with a change in this mortality difference.
We extracted patient-level data from national routinely collected administrative data (Hospital Episode Statistics or HES) from 1 January 2008 to 31 December 2014. Records include information of all admissions to English National Health Service (NHS) hospital trusts. Each patient record contains information on demographics (such as sex, age and ethnicity), the episode of care (such as trust name, date of admission) and diagnosis.
Our study covers a 30-month period before (January 2008 to June 2010) the reorganisation of stroke service in Greater London, and a 54-month period afterwards (July 2010 to December 2014). All admissions during the same period in the rest of England were used as controls.
Across England, the higher 7-day and 30-day in-hospital mortality risk associated with patients with stroke admitted during weekends compared with weekdays declined during the study period, to the extent that it was no longer statistically significant in the most recent year (2014). In Greater London, an adjusted 28% (RR=1.28, 95% CI 1.09 to 1.47) higher weekend/weekday 7-day mortality ratio in 2008 declined to a non-significant 9% higher risk (RR=1.09, 95% CI 0.91 to 1.32) in 2014. For the rest of England, a 15% (RR=1.15, 95% CI 1.09 to 1.22) higher weekend/weekday 7-day mortality ratio in 2008 declined to a non-significant 3% higher risk (RR=1.03, 95% CI 0.97 to 1.10) in 2014. During the same period, in Greater London an adjusted 12% (RR=1.12, 95% CI 1.00 to 1.26) weekend/weekday 30-day mortality ratio in 2008 slightly increased to 14% (RR=1.14, 95% CI 1.00 to 1.30); however, it was not significant.
While other research has suggested that centralisation of stroke care in London is associated with better outcomes generally, we in addition observe a gradual reduction in the weekend effect for emergency stroke admissions across England between 2008 and 2014. Although we cannot rule out an effect from centralisation, we found no statistical association with the reorganisation of services in London. This is unlikely to be due to changes in casemix or coding, and is consistent with a more general pattern of service improvement across the country with increased specialisation, as well as improved 24/7 delivery of care. While we have not specifically looked at staffing levels, it has not escaped our notice that our observed reductions in the ‘weekend effect’ occurred before any contractual changes for medical staffing in the UK.