Stroke risk factors, prevalence worse in rural areas

Despite living in a country with universal healthcare, Canadians residing in rural areas have more vascular risk factors and a higher incidence of stroke, even after adjusting for comorbidities and sociodemographic conditions.

“Rural residence is associated with an increased rate of stroke and mortality, which is attenuated but not eliminated after adjustment for baseline risk factors,” Moira K. Kapral, MD, MSc, with Toronto General Hospital, and colleagues wrote. They published their work Feb. 14 in Circulation: Cardiovascular Quality and Outcomes, using administrative databases from Ontario to capture risk factors along with stroke and all-cause mortality outcomes in nearly 6.3 million individuals.

“This suggests that risk factor modification is a necessary but insufficient target for future interventions in rural areas. Additional research is needed to understand and address other factors, such as variations in care or social determinants of health, that may contribute to rural morbidity and mortality.”

About 6.2 million of the study cohort were in the primary prevention group, while about 75,000 had a documented previous stroke and were classified as the secondary prevention cohort. Among the primary prevention individuals, those living in rural communities—fewer than 10,000 people—were less likely than urban residents to be screened for diabetes (70.9 percent vs. 81.3 percent) or hyperlipidemia (66.2 percent vs. 78.4 percent) and less likely to achieve control of diabetes with a hemoglobin A1c below 7 percent (51.3 percent vs. 54.3 percent).

They were also far likelier to have planned emergency department visits than city-dwellers but averaged fewer visits to family physicians and specialists.

However, in the secondary prevention cohort, the prevalence and treatment of risk factors was similar based on urban/rural status. The authors hypothesized this was because once a stroke has occurred, established cerebrovascular disease may be a stronger predictor of those risk factors than place of residence.

Despite adjusting for sociodemographic and comorbid conditions, Kapral et al. found rural residence was linked to a 6 percent higher risk of stroke in primary prevention and an 11 percent higher risk of repeat stroke in secondary prevention. Living in remote communities was also tied to increased death risks of 9 percent and 7 percent for primary and secondary prevention, respectively.

“The true rural/urban gradient in risk factor prevalence may be even greater than demonstrated in our study because lower screening rates or survey response rates may have led to underestimates of the prevalence of diabetes mellitus, hyperlipidemia, and smoking in rural areas,” the researchers wrote. “These findings support the need for enhanced identification and management of vascular risk factors in rural settings.”

Kapral and colleagues suggested the potential urban/rural disparities observed in their study could be even greater in places such as the U.S. where rural residents are more likely to be uninsured.