# Geospatial optimization of Air-Mobile Stroke Unit deployment in Norway: expanding the frontiers of neurocritical care

## TL;DR

This study uses geospatial modeling to find the best locations for Air-Mobile Stroke Units in Norway to improve stroke care in rural areas.

## Contribution

The study introduces a novel approach combining geospatial analysis and optimization to strategically deploy Air-Mobile Stroke Units.

## Key findings

- An Air-MSU in Dombås covers 87.5% of stroke patients, increasing treatment availability to 94.8%.
- Harstad is optimal for rural patients, raising eligibility for treatment to 97.2%.
- Geospatial modeling supports strategic planning for prehospital stroke services.

## Abstract

Rural and remote communities face disadvantages in acute stroke care. An Air-Mobile Stroke Unit (Air-MSU), adapting traditional MSUs for aircraft, could enable timely prehospital assessment in underserved regions. This modeling study aimed to identify the optimal Air-MSU base in Norway to maximize patient coverage, using increased geographic reach within 4.5 h as a proxy for clinical efficacy and improved outcomes.

All Helicopter Emergency Medical Services (HEMS) bases in Norway were evaluated as candidate sites using 2022 Norwegian Stroke Registry data at the postal-code level. Postal codes within a 15-min drive of a hospital were excluded to reflect realistic ground-ambulance coverage. Additional analyses focused on rural patients located more than 150 min from a hospital, assumed ineligible for hyperacute treatment within 4.5 h of onset. A Maximum Covering Location Problem (MCLP) model identified the HEMS base that maximized patient coverage within a 150-min response window.

Positioning the Air-MSU at Dombås in Central Norway covered 87.5% of stroke patients, increasing nationwide hyperacute treatment availability from 91.8 to 94.8%. For rural patients, the optimal base was Harstad in Northern Norway, covering 14.7% of all stroke patients but increasing the total proportion eligible for treatment within 4.5 h to 97.2%.

Locating an Air-MSU in Harstad would most effectively improve access to hyperacute stroke care in rural and remote Norway. Geospatial modeling combined with mathematical optimization supports strategic planning of future prehospital stroke services.