Stroke recurrence rates vary by U.S. region
Research Activities, November 2010, No. 363
Recurrent ischemic stroke is a common event and a major cause of disability and death. A national study of 895,916 Medicare patients with stroke found that 9.4 percent experience another ischemic stroke necessitating rehospitalization within a year. The Southeastern, Atlantic, and Central United States all had higher rates of recurrent stroke, while lower rates were present in the Western and Northeastern regions, according to a new study. Regional variation was present for all racial/ethnic subgroups and persisted after adjustment for individual patient characteristics.
Prior to this study, regional variation for stroke mortality and stroke hospitalization rates had been demonstrated, but little was known about the geographic pattern of recurrent stroke. The researchers looked at county-level data for elderly Medicare fee-for-service beneficiaries between 2000 and 2002. Patients with recurrent stroke were more often male, younger, black, had more illnesses, higher rates of diabetes, and were more likely to have two or more hospitalizations in the prior year. However, risk factors and population demographics do not appear to account for the increased risk of recurrent stroke in the Southeast and other regions.
The reasons why high stroke incidence and recurrence are higher in certain parts of the United States remain unclear. Future research is need to determine if other factors such as genetic variation, environmental factors, health care services, and infectious disease exposure might be associated with regional patterns in stroke outcomes. This study was supported by the Agency for Healthcare Research and Quality (HS16959).
See "Geographic variation in one-year recurrent ischemic stroke rates for elderly Medicare beneficiaries in the U.S.A.," by Norrina B. Allen, Ph.D., M.P.H., Theodore R. Holford, Ph.D., Michael B. Bracken, Ph.D., and others in Neuroepidemiology 34, pp. 123-129.