Disparities in imaging utilization for acute ischemic stroke based on patient insurance status

Previous studies have shown socioeconomic disparities in imaging utilization for both acute and chronic diseases. We studied a nationwide database to determine whether insurance-based disparities exist in the utilization of imaging for acute ischemic stroke.

Inpatients with a primary diagnosis of acute ischemic stroke from November 2005 through December 2011 were identified from the Perspective database. Patients were stratified into four groups according to insurance status as follows: uninsured, Medicaid, Medicare, and private insurance. Utilization rates of head CT, perfusion CT, head MRI, noninvasive head angiography (including head CT angiography [CTA] and head MR angiography [MRA]), noninvasive neck angiography (including neck CTA and neck MRA), carotid ultrasound, and echocardiography were compared using a chi-square test. A multivariable logistic regression model adjusting for potential confounding variables was fit to determine the association between insurance status and imaging utilization.

A total of 210,212 patients were included in this study: 10,396 patients (5.0%) were uninsured, 14,243 patients (6.8%) had Medicaid, 153,209 patients (72.9%) had Medicare, and 32,364 patients (15.4%) had private insurance. Even after we had controlled for confounding variables, significant disparities existed in imaging utilization. Compared with patients with private insurance, uninsured patients had significantly lower odds of noninvasive head angiography (odds ratio [OR] = 0.78, 95% CI = 0.74-0.81, p < 0.0001), neck angiography (OR = 0.79, 95% CI = 0.76-0.83, p < 0.0001), and head MRI (OR = 0.77, 95% CI = 0.74-0.81, p < 0.0001). The same was true for Medicaid and Medicare patients.

Disparities exist in the utilization of noninvasive head and neck imaging, MRI, and echocardiography for patients with acute ischemic stroke based on patient insurance status. More research is needed to understand these disparities.