Urban-rural inequalities in IV thrombolysis for acute ischemic stroke: A nationwide study

Abstract

Introduction: Rural residency has been associated with lower reperfusion treatment rates for acute ischemic stroke in many countries. We aimed to explore urban-rural differences in IV thrombolysis rates in a small country with universal health care, and short transport times to stroke units.

Patients and methods: In this nationwide cohort study, adult ischemic stroke patients registered in the Danish Stroke Registry (DSR) between 2015 and 2020 were included. The exposure was defined by residence rurality. Data from the DSR, Statistics Denmark, and the Danish Health Data Authority, were linked on the individual level using the Civil Registration Number. Adjusted treatment rates were calculated by balancing baseline characteristics using inverse probability of treatment weights.

Results: Among the included 56,175 patients, prehospital delays were shortest for patients residing in capital municipalities (median 4.7 h), and longest for large town residents (median 7.1 h). Large town residents were predominantly admitted directly to a comprehensive stroke center (98.5%), whereas 30.9% of capital residents were admitted to a hospital with no reperfusion therapy available (non-RT unit). Treatment rates were similar among all non-rural residents (18.5%-18.7%), but slightly lower among rural residents (17.2% [95% CI 16.5-17.8]). After adjusting for age, sex, immigrant status, and educational attainment, rural residents reached treatment rates comparable to capital and large town residents at 18.5% (95% CI 17.7-19.4).

Discussion and conclusion: While treatment rates varied minimally by urban-rural residency, substantial differences in median prehospital delay and admission to non-RT units underscored marked urban-rural differences in potential obstacles to reperfusion therapies.

Keywords: Healthcare disparities; fibrinolytic agents; ischemic stroke; reperfusion; rural population; thrombolytic therapy; urban population.

Graphical abstract

Figure 1.

Simplified causal diagram illustrating the causal relationship between rurality, IV thrombolysis and relevant covariates. The graph is not exhaustive. *Arriving hospital denotes available reperfusion therapies at the first admitting hospital.

Figure 2.

Study flow chart.

Figure 3.

Treatment rates according to urban-rural stratum. (a) Unadjusted treatment rates, (b) confounder adjusted rates, and (c) fully adjusted rates. Confounder adjustments included age, sex, immigrant status, and educational level. Full adjustments additionally included stroke severity, living alone, assisted living residency, CCI, previous stroke, hypertension, ongoing anticoagulation therapy and prehospital delay. Top: Treatment rates by urban-rural stratum displayed in geographic maps with stroke centers plotted as dots. CSC’s: Both thrombectomy and IV thrombolysis, PSC’s: Only IV thrombolysis, no RT: No reperfusion therapy. Middle: Treatment rates with 95% CI’s are at national level and according to urban-rural stratum. Bottom: Plots displaying treatment rates by urban-rural stratum with 95% CI. National treatment rates are indicated with a red line for comparison. CCI: Charlson Comorbidity Index; CI: confidence interval; CSC: Comprehensive Stroke Center; IVT: intravenous thrombolysis; PSC: Primary Stroke Center; RT: Reperfusion Therapy.

Figure 4.

Treatment rates according to urban-rural stratum among patients with early hospital arrival (<4 h). (a) Unadjusted treatment rates, (b) confounder adjusted rates, and (c) fully adjusted rates. Confounder adjustments included age, sex, immigrant status, and educational level. Full adjustments additionally included stroke severity, living alone, assisted living residency, CCI, previous stroke, hypertension, ongoing anticoagulation therapy and prehospital delay. Top: Treatment rates by urban-rural stratum displayed in geographic maps with stroke centers plotted as dots. CSC’s: Both thrombectomy and IV thrombolysis, PSC’s: Only IV thrombolysis, no RT: No reperfusion therapy. Middle: Treatment rates with 95% CI’s are at national level and according to urban-rural stratum. Bottom: Plots displaying treatment rates by urban-rural stratum with 95% CI. National treatment rates are indicated with a red line for comparison. CCI: Charlson Comorbidity Index; CI: confidence interval; CSC: Comprehensive Stroke Center; IVT: intravenous thrombolysis; PSC: Primary Stroke Center; RT: Reperfusion Therapy.