is an established effective anti-platelet and anti-inflammatory agent. deaths remained inconclusive partly because of the inadequate numbers of these end points.4 The persistent and well-documented Stroke Belt region of the United States has a 40% to 50% higher stroke mortality Kobe2602 than other areas.5 6 Within the Stroke Belt there is substantial heterogeneity in stroke mortality where a region along the coastal plain of North Carolina South Carolina and Georgia (the “Buckle of Stroke Belt”) possessing a stroke mortality nearly twice the national average.7 8 The increased relative risk in the Stroke Belt is persistent with Kobe2602 recent reports indicating a 43% higher odds of prevalent stroke in the Southeastern US and a racial disparity in stroke is well recorded.9 10 We previously reported data on prevalent aspirin use by race and geographic region of the US and the use of aspirin taken for primary prophylaxis.11 In that paper we postulated that differences between rates of aspirin use might represent one possible contributor to the racial and geographic differences in stroke risk but our cross-sectional analysis showed that aspirin use was more common in the Stroke Belt Rabbit Polyclonal to ADNP. compared to the rest of the country suggesting that differential aspirin use in the Stroke Belt was an unlikely explanation for geographic disparities in stroke. We did observe a higher use of prophylactic aspirin in whites vs blacks. Herein using the same cohort with prospective follow-up we evaluate the association of baseline prophylactic aspirin use with subsequent stroke including assessment of racial sex and geographic differences. METHODS Study Population The Reasons for Geographic and Racial Differences in Stroke (REGARDS) Study is a national population-based longitudinal cohort study with oversampling of African Americans (AAs) and persons living in the Stroke Belt region of the United States. Between January 2003 and October 2007 30 239 individuals were enrolled including race groups (42% AA 58 white) and both sexes (45% men and 55% women). The sample includes 21% of participants from the Stroke Belt Buckle (coastal plain region of North Carolina South Carolina and Georgia) 35 from the Stroke Belt states (remainder of North Carolina South Carolina and Georgia plus Alabama Mississippi Tennessee Arkansas and Louisiana) and the remaining 44% from the other 40 contiguous states (referred to as non-Belt). REGARDS participants were selected from commercially available lists (Genesys). A letter and brochure informed participants of the study and a follow-up phone call introduced the study Kobe2602 and solicited participation. During that call verbal consent was obtained and a 45-minute Kobe2602 questionnaire was administered. The verbal consent included agreement to participate in a subsequent in-person examination. The telephone response rate was 33% and the cooperation rate was 49% (similar to other reported epidemiologic studies).12 Demographic information and medical history including a history of cardiovascular disease and risk factors was obtained by trained interviewers using a computer assisted telephone interview (CATI). Participants were considered to be enrolled in the study if they completed the 45-minute telephone questionnaire and the in-person physical examination. The exam included anthropometric and blood pressure measurements blood samples and an electrocardiogram conducted 3-4 weeks after the telephone interview. Written consent was obtained during the in-person visit. Participants or their proxies were contacted by telephone at 6-month intervals for identification of medical events. Medical records were obtained for suspected strokes and were reviewed by at least 2 physician members of a committee of stroke experts. Stroke events were defined following World Health Organization (WHO) definition and further classified as ischemic or hemorrhagic. Incident stroke was defined as the first occurrence of physician-adjudicated stroke. The study methods were reviewed and approved by all involved Institutional Review Boards. Additional methodological details are provided elsewhere.8 Analysis Methods The primary goal of the analysis was to assess differences in stroke incidence by prophylactic aspirin usage. The primary independent variable was aspirin use. A participant was considered a “regular aspirin user” if they answered affirmatively to the question “Are you.