Prevalence of atrial fibrillation in Thai elderly.

Atrial fibrillation (AF) is an important health problem due to its association with serious complications. Stroke is one of the most serious complications and is the leading cause of death and disabilities in this population. AF increases the risk of embolic stroke five times compared to general population. The prevalence of AF varies from 0.5%15% depending on studied populations such as age, gender, as well as geographic. Aging is an important factor for the AF pathophysiology, and the prevalence of AF increases with age. The prevalence of AF in elderly aged more than 65 years was 7.2%, while the incidence of AF in octogenarians has been reported of 20.7/1000 population per year. 10]  Age is the strong predictor of stroke in patients with non-valvular AF. Therefore, it has been recommended that elderly patients with non-valvular AF (age > 65 years) should receive long-term oral anticoagulation. As a result, systematic or opportunistic screening increased AF detection as well as opportunity to start thromboembolic prophylaxis. However, the cost effectiveness for screening depends on the prevalence of AF. In Thailand, the prevalence of AF has been surveyed in a large scale study during 1998–1999 with a prevalence of 3.6 per thousand in population of 30 years or older. Nevertheless, the prevalence of AF in elderly Thai population is unknown. Therefore, this survey was conducted to determine the prevalence of AF in elderly Thai population. Maerim is one of the largest district of Chiang Mai which is the metropolitan city situated in the northern part of Thailand. The city has a land area of 443.6 km with a population of 84,433. Among these, 10,805 subjects were 65 years or older. There are 14 primary health care centers and one tertiary health care center in Maerim. This study is a