Functional outcomes after ischemic stroke have improved over the past few decades, while no significant changes have been observed in patients with hemorrhagic stroke, according to study results published in JAMA Neurology.
Long-term changes in age at onset, incidence and mortality of stroke have been observed in several populations. For example, according to the researchers, the age-adjusted incidence and mortality from stroke in Japan has declined over the past half century. However, there has been a slowdown in recent decades. Researchers believe that recent changes in demographics and therapeutic technologies may play a role in neurological severity and functional outcomes in stroke patients.
The aim of the current study was to determine the impact of changes in demographic characteristics and therapeutic technologies on stroke severity and functional outcomes in acute stroke patients by gender.
Researchers used the Japan Stroke Data Bank, a 20-year-old nationwide hospital-based registry of hospitalized patients with acute stroke or transient ischemic attack from 130 academic or regional stroke centers across Japan from January 2000 to December 2019. A total of 135,266 patients (39.8% women ; mean age 74 years) with ischemic stroke, 36,014 patients (42.7% women; mean age 70 years) with intracerebral hemorrhage and 11,800 patients (67.2% women; mean age 64 years) with subarachnoid hemorrhage were identified.
The National Institutes of Health Stroke Scale was used to assess initial severity of ischemic stroke or intracerebral hemorrhage and the World Federation of Neurological Surgeons was used to assess the severity of subarachnoid hemorrhage. Functional outcomes were determined using the modified Rankin scale (mRS).
Across all 3 stroke types, initial stroke severity, as determined by the National Institutes of Health Stroke Scale or the World Federation of Neurological Surgeons Scores, decreased over the 20-year period. In addition, median age at onset increased and unfavorable outcomes (mRS from 5 to 6) and in-hospital deaths decreased in both males and females.
In patients with ischemic stroke, favorable outcomes increased over time after age adjustment, but then stagnated or even declined in men. However, after multivariable adjustment, including reperfusion therapy, the improvement in functional outcome was no longer significant.
In patients with intracerebral hemorrhage, favorable outcomes (mRS from 0 to 2) decreased over time in both males and females, but unfavorable outcomes and deaths only decreased in females. In patients with subarachnoid hemorrhage, no change in the proportion of patients with favorable outcomes was reported, while the rate of unfavorable outcomes and deaths decreased in both males and females.
The study had several limitations, including potential bias as high-volume stroke centers were more likely to participate in the study and results may not generalize to low-volume hospitals, exclusion of more than 6000 patients due to unavailable data on stroke types or demographics, no long-term results and no available data on the impact of the COVID-19 pandemic on the results.
“[S]Stroke has become milder regardless of gender or stroke type over the past 20 years, although the age at onset of stroke in the National Stroke Registry in Japan has increased. Short-term functional outcomes at hospital discharge gradually improved in patients with IS [ischemic stroke], presumably due in part to the development of acute reperfusion therapy. In contrast, the outcomes of patients with hemorrhagic stroke did not improve significantly over the same period,” the researchers concluded.
disclosure: Some study authors declared their affiliation with biotech, pharmaceutical, and/or device companies. For a full list of authors’ disclosures, see the original reference.
Toyoda K, Yoshimura S, Nakai M et al. Twenty-year change in severity and outcome of ischemic and hemorrhagic stroke. JAMA Neurol. Published online December 6, 2021. doi:10.1001/jamaneurol.2021.4346