Mortality following ischaemic stroke

Stroke is a leading cause of death, accounting for 7% of deaths across the OECD in 2019 (see indicators “Main causes of mortality” and “Mortality from circulatory diseases” in Chapter 3). A stroke occurs when the blood supply to a part of the brain is interrupted, leading to necrosis (cell death) of the affected part. Of the two types of stroke, about 85% are ischaemic (caused by clotting) and 15% are haemorrhagic (caused by bleeding). The COVID-19 pandemic has so far had a varying impact on access to and quality of care for stroke patients across OECD countries.

Figure 6.17 shows the case fatality rates within 30 days of hospital admission for ischaemic stroke where the death occurred in the same hospital as the initial admission (unlinked data). Figure 6.18 shows the case fatality rate where deaths are recorded regardless of where they occurred, including in another hospital or outside the hospital where the stroke was first recorded (linked data). The indicator using linked data is more robust because it captures fatalities more comprehensively than the same-hospital indicator, but it requires a unique patient identifier and the capacity to link data, which are not available in all countries.

Across OECD countries, 7.7% of patients in 2019 died within 30 days of hospital admission for ischaemic stroke using unlinked data (Figure 6.17). The case fatality rates were highest in Mexico, Latvia, Lithuania and Poland – all with mortality rates over 11%. Rates were lower than 4% in Costa Rica, Japan, Korea, Norway and Iceland. Low rates in Japan are due in part to efforts dedicated to improving the treatment of stroke patients in hospitals, through systematic blood pressure monitoring, major material investment in hospitals and establishment of specialised stroke units (OECD, 2015[28]).

Across the 26 countries that reported linked data, 11.8% of patients died within 30 days of being admitted to hospital for stroke (Figure 6.18). This figure is higher than the same-hospital indicator as deaths are recorded regardless of where they occurred after hospital admissions (i.e. either in the hospital where the patient was initially admitted, after transfer to another hospital or after being discharged).

Treatment for ischaemic stroke has advanced dramatically over recent decades, with systems and processes now in place in many OECD countries to identify suspected ischaemic stroke patients and to deliver acute reperfusion therapy quickly. Between 2009 and 2019, case fatality rates for ischaemic stroke decreased substantially across OECD countries: from 9.8% to 7.7% for unlinked data rates and from 13.7% to 11.8% for linked data rates (Figure 6.17 and Figure 6.18). Countries can further improve quality of stroke care through timely transportation of patients, evidence-based medical interventions and access to high-quality specialised facilities such as stroke units (OECD, 2015[28]). Timely care is particularly important, and advances in technology are leading to new models of care to deliver reperfusion therapy in an even more speedy and efficient manner, whether through pre-hospital triage via telephone or administering the therapy in the ambulance.

Between 2019 and 2020, case fatality rates increased in Lithuania and Portugal, while the rates were stable in countries such as Canada, Iceland, Latvia, the Slovak Republic and England (United Kingdom) (Figure 6.17 and Figure 6.18). However, the number of people admitted to hospital due to ischaemic stroke decreased in these countries – particularly in Portugal, where the extent of reduction was also large for AMI (see indicator “Mortality following acute myocardial infarction”). Reductions in hospital admissions due to stroke and the number of procedures for stroke were also reported in France, Italy, Germany, Spain and the United States. These reductions may have occurred because at least some people who had strokes did not seek hospital care immediately due to a fear of becoming infected with COVID-19, or because pre-hospital triage did not function as well and ambulance systems may not have been able to transfer all patients promptly due to surges in demand. The number of ischaemic stroke patients who died after hospital admission decreased in most countries that provided 2020 data. The decrease was significant in Portugal, suggesting that at least some stroke patients may have died at home or in long-term care institutions before arriving at hospital.

In order to tackle resource constraints during the COVID-19 crisis, countries such as France, Germany and Italy reorganised pathways for acute stroke care, and stroke care was sometimes concentrated in a few hospitals (Bersano et al., 2020[29]). Supplementary data such as ambulance callouts, ambulance response times and door-to-needle time from emergency room arrival to initiation of thrombolysis are needed to assess the impact of COVID-19 on acute care for stroke patients and to support health systems in providing high-quality acute care during public health emergencies. Granular data such as hospital admissions and case fatality rates by stroke severity could further inform ways to promote effective provision and management of acute care, particularly to patients with the greatest needs.

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