Hannah Roeder, MD, MPH
Eriksson M, Åsberg S, Sunnerhagen KS, von Euler M, on behalf of the Riksstroke Collaboration. Sex Differences in Stroke Care and Outcome 2005–2018: Observations From the Swedish Stroke Register. Stroke. 2021.
In this article, Eriksson et al. investigate whether stroke incidence, care, outcome, and sex differences changed between the years 2005 and 2018 in Sweden. Using data from the Swedish Stroke Register, a national registry including all Swedish hospitals admitting acute stroke patients, the authors highlight improvements in stroke care and narrowing sex gaps.
Sweden had a decreasing incidence of stroke over the 14-year period despite an aging and growing population. The authors propose that primary prevention and behavioral changes, such as less tobacco use, in the population contributed.
The use of reperfusion therapy grew exponentially from 2.3% to 15.1% of all stroke patients, which likely owes to changes in stroke knowledge and recommendations over the time frame. Several groundbreaking stroke trials, published between 2005 and 2018, expanded the indications for thrombolysis and supported the efficacy of mechanical thrombectomy. Additionally, the difference in reperfusion rates between men and women that were present in 2005 had resolved by 2018. However, women remained less likely to receive thrombolysis within the Swedish national guideline of 30 minutes from hospital arrival (18.4% versus 20.5%), which was not explained by women being more likely to live alone, according to the authors. A major unanswered question is why inequity in time to thrombolysis persists; potential explanations, such as differences in stroke symptoms, hesitancy to receive thrombolysis, or difficulty obtaining intravascular access, should be studied to help expedite time to treatment in women.
Regarding secondary prevention, among patients with atrial fibrillation and stroke, men had a higher likelihood of being treated with anticoagulation initially. By the end of the study period, anticoagulation treatment vastly increased among both sexes, paralleling growing evidence for the benefit of anticoagulation for secondary stroke prevention in atrial fibrillation. The age-adjusted rate of anticoagulant treatment for women had surpassed that of men (31.2% in 2005 to 78.6% in 2018 in men versus 26.7% to 81.9% in women). Similarly, the use of statins more than doubled during the study period, likely due to the publication of trials demonstrating the benefit of secondary prevention with lipid-lowering medications, with women narrowing but not closing the gap in statin therapy (36.9% in 2005 to 83.7% in 2018 in men versus 32.3% to 81.2% in women).
The main strength of this study is use of nationwide data in a longitudinal manner to examine temporal trends to study sex differences in stroke care. However, the study is constrained by the data that is present in the national registry and the accuracy of the database. Another limitation is the low external validity, as trends in the relatively homogenous population of Sweden may not be generalizable to other populations. Whether the temporal trends and narrowing of sex-based inequities are present across socioeconomic levels, ethnicities, and urban/rural areas is unknown. Sex differences in thrombolytic therapy in the United States identified from analysis of the Nationwide Inpatient Sample from 1999 to 2004 (when thrombolytic therapy was infrequently used) may be vastly different today.1 Future research should investigate whether similar strides in stroke care equity have been made in other countries. Overall, the findings are promising to suggest that sex disparities in stroke care may be improving, but more investigation is required to discover why some inequities may persist and how to address them.
- Schumacher, H.C., Bateman, B.T., Boden-Albala, B., Berman, M.F., Mohr, J.P., Sacco, R.L. and Pile-Spellman, J. Use of thrombolysis in acute ischemic stroke: analysis of the Nationwide Inpatient Sample 1999 to 2004. Annals of emergency medicine. 2007;50(2):99-107.