Compact City Design May Improve Stroke Care, Outcomes Regardless of Urbanization

Stroke care provision and outcomes may be improved with or without large-scale urbanization using a compact city design at the community level, according to study findings published in the Journal of the American Heart Association.

More than 50% of the world’s population live in urban areas—a proportion that may reach 70% by mid-century—placing a priority on efficient regional urban planning.

Investigators in Japan explored the impact of zip-code area-level compact city design on stroke outcomes. Walkability, measured by the walkability index (WI), is an urban planning model promoting intensified urban form (destination accessibility, diversity, higher levels of density) embodied by the compact city concept.

The investigators used nationwide data from the J-ASPECT study (2017-2022) and ICD-10 codes to conduct a retrospective cohort study examining the association between WI and medical costs, in-hospital mortality, and functional independence at discharge in patients with stroke. Briefly, J-ASPECT, initiated in 2010, is a nationwide survey of acute stroke clinical practices using data from the health insurance claims database in Japan. All 113,156 zip code areas in Japan were included in the calculation of the WI (average of road connectivity, population density, and variation in walkable facilities). Patients with emergency admission or admission within 3 days of stroke onset were included, whereas those with admission for diagnostic purposes, elective surgery, or rehabilitation were among those excluded.

Zip code area-level compact city design was associated with decreased in-hospital mortality and increased functional independence.

More than half-a-million patients (N=555,296; median age, 75 [IQR range, 66-83]; 42.5% women) were included in the analysis. All patients (from 818 hospitals) were categorized into quartile groups by WI. Compared with the lowest WI group, the highest group had fewer women and younger patients, as well as higher prevalence of smoking and dyslipidemia, although a lower prevalence of hypertension. Patients in the highest WI group had better socioeconomic status, lived closer (shorter road-distance) to the hospital, and were more likely to receive surgical treatment and be managed in the care unit.

Higher WI was significantly associated with decreased in-hospital mortality (odds ratio [OR], 0.94; 95% CI, 0.92-0.96) and increased functional independence (OR, 1.03; 95% CI, 1.02-1.04). Primarily mediated by management in stroke or intensive care units, the highest WI group was associated with decreased mortality (proportion mediated, 0.46; 95% CI, 0.35-0.63). Primarily mediated by short road-distance to the hospital, the highest WI group was associated with increased functional independence (proportion mediated, 0.30; 95% CI, 0.21-0.44).

Study limitations include limited generalizability, the retrospective design, the included WI factors do not capture the full impact of city design that could influence stroke outcomes, and possible selection bias.

“Zip code area-level compact city design was associated with decreased in-hospital mortality and increased functional independence,” the investigators concluded. “Compact city design at community level, even without large-scale urbanization, may contribute to improving stroke care provision and outcomes in increasingly urbanized societies.”

This article originally appeared on The Cardiology Advisor