ATRIAL FIBRILATION OPPORTUNISTIC SCREENING AND STROKE (AFOSS).

People: The absolute prevalence of undiagnosed atrial fibrillation in individuals over 60 years of age is 2.2%, equivalent to 20.1% of the overall prevalence of AF and there is not sufficient evidence regarding the procedures that may be most effective for achieving an early diagnosis of AF and reducing the associated stroke risks. Intervention: Characterize the ideal population for searching unknown atrial fibrillation and develop an understanding of actions that could be taken today to improve the diagnosis and management of AF. C: Compare two large populations with and without opportunistic screening of AF about stroke incidence. Outcome: MAIN OBJECTIVES 1. Compare two large populations with and without opportunistic screening of AF. 2. Relate the incidence of stroke episode with the AF diagnosis 3. Characterize the ideal population for searching unknown atrial fibrillation by making a multivariate predictor model. 4. Develop an understanding of actions that could be taken today to improve the diagnosis and management of AF. 5. Evaluate whether intervention results in improved outcomes