Costs and outcomes of noncardioembolic ischemic stroke in a managed care population

Nicole M Engel-Nitz1, Stephen D Sander2, Carolyn Harley3, Gabriel Gomez Rey1, Hemal Shah21Health Economic and Outcomes Research, i3 Innovus, Eden Prairie, MN, USA; 2Health Economic and Outcomes Research, Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA; 3Health Economic and Outcomes Research, i3 Innovus, Palo Alto, CA, USAPurpose: To evaluate the clinical outcomes and incremental health care costs of ischemic stroke in a US managed care population.Patients and methods: A retrospective cohort analysis was done on patients (aged 18+ years) hospitalized with noncardioembolic ischemic stroke from January 1, 2002, through ­December 31, 2003, identified from commercial health plan administrative claims. New or recurrent stroke was based on history in the previous 12 months, with index date defined as first date of ­indication of stroke. A control group without stroke or transient ischemic attack (TIA) was matched (1:3) on age, sex, and geographic region, with an index date defined as the first ­medical claim during the patient identification period. Patients with atrial fibrillation or mitral value abnormalities were excluded. Ischemic stroke and control cohorts were compared on 4-year clinical outcomes and 1-year costs.Results: Of 2180 ischemic stroke patients, 1808 (82.9%) had new stroke and 372 (17.1%) had a recurrent stroke. Stroke patients had higher unadjusted rates of additional stroke, TIA, and fatal outcomes compared with the 6540 matched controls. Recurrent stroke patients had higher rates of adverse clinical outcomes compared with new stroke patients; costs attributed to recurrent stroke were also higher. Stroke patients were 2.4 times more likely to be hospitalized in follow-up compared with controls (hazard ratio [HR] 2.4, 95% confidence interval [CI]: 2.2, 2.6). Occurrence of stroke following discharge was 21 times more likely among patients with index stroke compared with controls (HR 21.0, 95% CI: 16.1, 27.3). Stroke was also predictive of death (HR 1.8, 95% CI: 1.3, 2.5). Controlling for covariates, stroke patients had significantly higher costs compared with control patients in the year following the index event.Conclusion: Noncardioembolic ischemic stroke patients had significantly poorer outcomes and higher costs compared with controls. Recurrent stroke appears to contribute substantially to these higher rates of adverse outcomes and costs.Keywords: burden of illness, stroke⁄cerebrovascular accident, cardiovascular disease, claims analysis, costs of care, health care outcomes