Discussion

We found that the majority of rural residents in Ontario lived within 60 minutes of driving time from key stroke services, including neuroimaging and thrombolysis. However, geographic access was substantially lower for EVT, and many rural communities in northern Ontario did not have timely road access to any stroke services.

Previous studies evaluating geographic access to stroke services have estimated that over 80% of the US population has access to thrombolysis-capable hospitals within 60 minutes, with similar results seen in Ontario and other Canadian provinces.^{Reference Jewett, Mirian, Connolly, Silver and Sahlas10,Reference Eswaradass, Swartz, Rosen, Hill and Lindsay12,Reference Adeoye, Albright and Carr19} However, these studies assessed the entire population rather than rural communities, where access might be anticipated to be lower. Our finding that over 81% of rural residents lived within 60 minutes of driving time to thrombolysis centers provides evidence of very good rural access to this treatment. This is consistent with previously observed high thrombolysis treatment rates in both rural and urban areas of Ontario, and with elimination of rural/urban disparities in use over time, and may reflect the impact of a well-established regional system of coordinated stroke care in Ontario for this treatment.^{Reference Gonzales, Mullen, Skolarus, Thibault, Udoeyo and Willis20–Reference Kapral, Fang and Silver22}

Most existing systems of stroke care were developed prior to the demonstration of the effectiveness of EVT for acute ischemic stroke and were therefore not designed to ensure equitable access to this treatment.^{Reference Adeoye, Nyström and Yavagal4,Reference Grotta23} Studies from the USA have documented marked geographic variations in access to care, with lower access in states with a large proportion of rural residents.^{Reference Adeoye, Albright and Carr19,Reference Mullen, Branas and Kasner24} Our findings suggest that the majority of rural Ontarians cannot reach existing EVT centers within 60 minutes of driving time, and that the proportion living within 30 minutes of driving time is exceedingly small at 3.3%. Further, EVT is only indicated in patients with large vessel occlusion, which is estimated to be present in only 20% of patients with stroke.^{Reference Malhotra, Gornbein and Saver25} Identifying the presence of large vessel occlusion requires CTA, and the ability of only 51.1% of the population to reach this imaging modality within 30 minutes of driving time limits the ability to systematically screen potential EVT candidates and may result in suboptimal use of treatment and transportation resources. Although EVT can be provided to selected patients up to 24 hours after stroke symptom onset, outcomes are better with early therapy, so timely access is essential.^{Reference Meretoja, Keshtkaran, Tatlisumak, Donnan and Churilov26,Reference Mulder, Jansen and Goldhoorn27} Furthermore, patient selection in the post-6-hour window is based on CT perfusion imaging that is currently not available in most Ontario hospitals.^{Reference Albers, Marks and Lansberg28}

Potential solutions to improve rural EVT access include promoting the use of emergency medical services for acute stroke, as previous research suggests that rural residents with suspected stroke are less likely than those in large urban centers to arrive at hospital by ambulance.^{Reference Koifman, Hall and Li21} For some remote communities, the use of air rather than ground transportation will be necessary, although factors such as availability of aircraft, airports, and fly time from base to community may all affect transit times, and air transportation may be particularly unreliable in northern communities because of poor weather. Other potential solutions include the use of mobile stroke units, prehospital triage, telemedicine for decision support, and flying intervention teams.^{Reference Fassbender, Grotta, Walter, Grunwald, Ragoschke-Schumm and Saver29–Reference Shuaib and Jeerakathil36} Direct transportation to intervention centers may be preferable to interhospital transfers, which can be associated with delays in treatment and worse outcomes.^{Reference Grotta23,Reference Shah, Xian and Sheng37–Reference Allen, Pearn and James39} The designation of additional endovascular centers in underserved areas may be part of the solution, although it may be challenging to maintain a roster of staff and neurocritical care services in such areas, and one Korean study found that outcomes were worse at small-volume compared to large-volume sites.^{Reference Kim, Baek, Heo, Kim, Nam and Kim40} Finally, allowing patients to seek care across provincial boundaries may reduce travel time to stroke care services.^{Reference Jewett, Harroud and Hill11}

Geographic access is important not only for time-sensitive hyperacute stroke interventions, but also for rehabilitation and stroke secondary prevention. Patients whose only access to rehabilitation facilities is many hours of drive from their home communities may opt to forgo inpatient rehabilitation because of the distance from family and other supports, potentially squandering initial gains from acute stroke care. Minor strokes and transient ischemic attacks make up over half of the burden of ischemic cerebrovascular diseases and are harbingers of potentially preventable larger disabling strokes, and long driving times to stroke prevention clinics limit the ability to provide rapid outpatient diagnostic testing and management to reduce the risk of stroke in this group.^{Reference Giles and Rothwell41} Our findings suggest that over one in five rural Ontarians are beyond 60 minutes of driving time of inpatient rehabilitation and stroke prevention clinics, and are consistent with a previous study that found that only 69% of Canadians had access to secondary prevention services that were operational 5 to 7 days a week.^{Reference Jewett, Harroud and Hill11}

Some rural communities are in close proximity to metropolitan areas while others are in remote northern locations. Not surprisingly, we found that geographic access by car was particularly low in northern Ontario, with a substantial proportion of residents living beyond 240 minutes of driving time of key stroke services. Many of these communities will always require air transportation for care for medical emergencies; however, the targeted designation of additional facilities may improve access in such areas. Currently, there is only one endovascular center in northern Ontario, but a second site is now being developed. Other potential strategies to improve access to care in remote areas include the use of telemedicine (including innovative technology that allows procedures to be performed remotely), telerehabilitation, and rural stroke coordinators in strategic locations.^{Reference Cadhilac, Purvis and Kilkenny42–Reference Housley, Garlow and Ducote44}

A number of study limitations merit comment. Our findings are specific to the geography and health system in the province of Ontario. However, we anticipate that these will be applicable to other jurisdictions with hub-and-spoke models of stroke care covering large distances and encompassing both rural and urban areas. Most of the postal codes in our study represented fairly confined geographic areas, with the exception of some postal codes in northern areas where population postal codes could represent larger geographic areas. Although this introduces uncertainty to the estimation of drive times in the north, any potential bias would be minimized by the fact that these postal codes are all located well beyond 60 minutes of driving time to the nearest health care facility, and thus our conclusions are unlikely to be affected by errors in estimated travel time based on postal code representation. Although the Acute Stroke Care Resource Inventory identified all designated stroke prevention clinics, stroke secondary prevention care may have been delivered through other mechanisms, such as cardiology clinics or individual clinicians’ offices. We did not study actual delivery of stroke care, but only geographic access to services. For example, we evaluated geographic access to facilities with the capacity to perform CT; however, not all of these provide daily round-the-clock service, and even those that do may require a technologist to travel from home, thus introducing further delays. Fourth, our analyses focused on driving times based on posted speed limits; however, actual driving speeds will be higher than posted ones for emergency vehicles and lower during difficult weather conditions or heavy traffic.^{Reference Freyssenge, Renard and Schott45} Not all people have access to vehicles, and use of driving time as a surrogate for access may overestimate access to care, especially in subgroups of people with lower car ownership.^{Reference Wong, Grande and Mitra46,Reference Fone, Christie and Lester47} True transit time includes not only driving time but also emergency medical services activation time, response time, on-scene time, and “door-in door-out” times for those seen first at a local hospital and subsequently transferred to a stroke center.^{Reference Carr, Caplan, Pryor and Branas48} For all of these reasons, our findings are likely to overestimate rural communities’ geographic access to stroke services. Fifth, we did not study issues specifically related to Indigenous people, who are more likely than their non-Indigenous counterparts to live in rural areas, and who may face additional barriers to care related to the historic effects of colonization.^{Reference Slater, Green and Shah49,Reference King, Smith and Gracey50} Finally, this study focused solely on rural communities, and thus the findings differ from those of studies of geographic access for all communities in the province.

This study provides evidence of very good overall geographic access to CT and thrombolysis from rural communities across Ontario. However, targeted solutions are needed to improve rural access to other stroke services, particularly EVT, and to improve access in northern Ontario.