Racial differences in the use of helicopters for emergent transfer of stroke patients

Vaughan-Sarrazin MS, Leira E. Racial differences in the use of helicopters for emergent transfer of stroke patients. Paper presented at: American Heart Association / American Stroke Association International Stroke Conference; 2015 Feb 10; Nashville, TN.

Background: The use of helicopters for emergency hospital to hospital transfers provides clinical benefit for patients with time-sensitive medical conditions by shortening delivery time to definitive care while providing specialized medical expertise and equipment to patients during transport. Racial differences in the use of helicopters for hospital to hospital transfers have not been investigated. Objective: Investigate racial differences in the use of air transportation for elderly Medicare beneficiaries presenting to emergency departments (ED) for stroke. Methods: Using Medicare claims from 2010-2011 for elderly Medicare beneficiaries with a previous diagnoses of atrial fibrillation, we identified 37,648 patients admitted to acute care hospitals with a primary diagnosis of stroke who also had an ED visit on the same day as the hospital admission. Patient demographics and comorbidity were determined from claims incurred during the 12 months prior to the stroke admission. Rural ED location was determined using Rural-Urban Commuting Area (RUCA) codes applied to the ED zipcode, and the hospital to hospital transfer distance was determined by the distance between ED and admitting hospital zipcodes. Statistical analyses compared rates of helicopter use unadjusted and adjusted for patient demographics, comorbidity, urban location, hemorrhage diagnosis, and census region. Results: Overall 10% of the hospital admissions were for cerebral hemorrhage and 90% for ischemic stroke. White patients comprised 79% of the total, with the remainder black (11%), Hispanic (6%), and other non-white race (4%). Compared to white patients, black, Hispanic and other non-white patients were more likely to reside in urban areas (87%, 92%, 93% vs 81%), and more likely to be dually enrolled in Medicaid (72%, 79%, 73% vs 29%). Comorbidity scores were higher for black and Hispanic compared to other nonwhite and white patients (3.15 and 3.13 vs 2.83 and 2.87), while mean age was lower for black and Hispanic patients compared to other nonwhite or white (63%, 68%, 715, 71% greater than age 75, respectively). Overall, 1.5%, 1.0%, 0.6%, 2.1% of black, Hispanic, other non-white race, and white patients were transported between care sites by helicopter. Helicopter use was higher for patients with cerebral hemorrhage versus ischemic stroke (14.1% vs. 2.1%). In risk adjusted analysis, black, Hispanic, and other non-white patients were only 0.56, 0.41, and 0.31 times as likely as white patients to be transported by helicopter (p < .01). This pattern was similar in urban areas, where black, Hispanic, other nonwhite patients were 0.55, 0.3, and 0.28 times as likely as whites to be transported by helicopter (p < .01). In rural areas, the relative likelihoods were 0.73, 0.57, 0.80 and were not statistically significant. In analysis that stratified patients by census region, significant racial differences in helicopter use were found in the South (Odds Ratio [OR] = 0.60, 0.26, 0.63 for black, Hispanic and other non-white compared to white patients), and Midwest (OR = 0.36, 0.26, 0.01), but not in the West or Northeast. Conclusions: Significant racial differences exist in the use of emergency air transportation. The use of evidence based clinical practice guidelines for air medical transport may reduce racial differences.