Summary: Between 2000 and 2015, the incidence of ischaemic stroke fell and outcomes improved markedly: one-year death after ischaemic stroke dropped by about 24% and the risk of disability fell by about 23%, changes the researchers attribute to advances in acute care and secondary prevention.
Source: National Institute for Health Research
Thousands more patients are surviving strokes and experiencing less long-term disability, according to an analysis of south London data led by researchers from Guy’s and St Thomas’.
This study, published in PLOS Medicine, examined people who experienced first-ever ischaemic strokes (strokes caused by a clot) in Lambeth and Southwark between 2000 and 2015, using the population-based South London Stroke Register. The analysis found substantial reductions in mortality and disability over the 15-year period, which the authors link to improvements in stroke care, diagnostic imaging and the use of acute treatments and medications.
After adjusting for changes in the underlying population, the researchers found that the one-year mortality following an ischaemic stroke fell from 32.6% in 2000 to 20.15% in 2015 — a relative reduction of about 24%. The proportion of survivors living with significant disability one year after stroke fell from 34.7% to 26.7% over the same period, a reduction of approximately 23%.
Scaling these improvements to the estimated 52,000 ischaemic strokes that occur annually across the UK, the team estimated roughly 6,300 additional people now survive beyond one year each year and about 3,200 fewer people each year live with stroke-related disability than would have been expected in 2000.
Stroke remains a major health issue in the UK, and ischaemic stroke — caused by interruption of blood flow to part of the brain — is a leading contributor to death and disability. In 2016 almost 38,000 people in the UK died from stroke, making it one of the top causes of mortality nationwide.
The South London Stroke Register, which has collected detailed, anonymised stroke data from the local population since 1995, provided the basis for this analysis. The research focused on 3,128 patients with first-ever ischaemic stroke recorded between 2000 and 2015. Previous work using the same register showed that overall stroke incidence in the area declined by 43% during the study interval.
Reductions in death and disability were seen across sexes and among both black and white patients. The study reports particularly strong improvements in cardio-embolic strokes and in patients aged 55 and over, with annual average reductions in mortality of about 2.4% and in three-month functional dependence of about 1.7% across the study period.
Dr Yanzhong Wang, Reader in Medical Statistics at King’s College London and a co-author of the study, commented that the findings are encouraging: improved survival and reduced disability indicate that stroke care and prevention are becoming more effective. The research team highlighted several likely contributors to the observed improvements: higher rates of hospital admission for stroke, more widespread use of CT and MRI scans for rapid diagnosis, and increased use of thrombolytic drugs and anticoagulant medications in the acute phase of ischaemic stroke. They also note the possibility that strokes are on average less severe than in earlier years, perhaps reflecting broader improvements in public health and risk factor management.
The authors thanked the many patients who contributed data to the South London Stroke Register, which relies on multiple data sources including anonymised emergency department records and information gathered by trained clinicians and field workers. The study received support from the NIHR Collaboration for Leadership in Applied Health Research and Care South London at King’s College Hospital NHS Foundation Trust and from the NIHR Biomedical Research Centre at Guy’s and St Thomas’ NHS Foundation Trust and King’s College London.
Study details and findings
The research used the South London Stroke Register population (about 357,308 people in 2011; 50.4% male; 56% white and 25% black) to identify all first-ever ischaemic strokes from 2000 to 2015. Ischaemic strokes were further classified by underlying mechanism: large-artery atherosclerosis (LAA), cardio-embolism (CE), small-vessel occlusion (SVO), other determined causes (OTH), and undetermined (UND). The investigators applied proportional-hazards survival models adjusted for demographics, prestroke risk factors, clinical case mix and processes of care to quantify temporal trends in survival. They also examined 30-day and one-year case-fatality rates and three-month functional dependence using the Barthel Index.
Among the 3,128 registered patients the median age was 70.7 years; 50.9% were male; ethnic composition was 66.2% white, 25.5% black and 8.3% other. From 2000–2003 to 2012–2015 the adjusted overall mortality decreased by 24% (hazard ratio per year 0.976). Thirty-day and one-year case-fatality rates fell by about 38% and 37% respectively, and the risk of functional dependence at three months decreased by 23% across the study period. The authors note limitations including small numbers in some subgroups (for example LAA), which may limit the power to detect trends within those categories.
Conclusions
This population-based analysis demonstrates meaningful declines in both mortality and short-term disability following ischaemic stroke between 2000 and 2015. The improvements are consistent with better acute stroke care, greater access to diagnostic imaging, and wider use of thrombolytic and anticoagulant therapies, along with potential reductions in stroke severity. Continued investment in stroke prevention, rapid diagnosis and evidence-based acute treatments remains essential to sustain and extend these positive trends.
Source:
National Institute for Health Research
Media Contacts:
Anna Perman – National Institute for Health Research
Image Source:
The image is in the public domain.
Original Research: Open access
“Long-term trends in death and dependence after ischaemic strokes: A retrospective cohort study using the South London Stroke Register (SLSR)”. Hatem A. Wafa, Charles D. A. Wolfe, Ajay Bhalla, Yanzhong Wang. PLOS Medicine. DOI: 10.1371/journal.pmed.1003048.