The prevalence of symptomatic knee and distal interphalangeal joint osteoarthritis in the urban population of Antalya, Turkey.

The aim of this cross-sectional study was to estimate the prevalence and risk factors of symptomatic knee and distal interphalangeal (DIP) joint osteoarthritis (OA) in the elderly (> or =50 years of age) urban population of Antalya, Turkey. According to the 1997 national census, Antalya's population was 508,840. By random cluster sampling, 655 individuals aged 50 years or more were interviewed face-to-face and subjected to structured interviews regarding knee pain, worsening pain on exertion, and the gelling phenomenon. They were also asked about performing namaz (a fundamental act of worship in Islam performed five times a day), smoking, type of residence, type of toilet, work style, and duration of walking per day. They were also questioned about swelling in DIP joints. In the case of suspicion of knee OA, the individuals were invited to the hospital for further evaluation by physical examination and direct roentgenogram. The diagnosis of knee OA was based on clinical or clinical and radiographic findings. The prevalence of symptomatic knee OA was determined as 14.8% in the population aged 50 years or over. Advanced age, female sex, namaz, and type of residence were found to be associated with knee OA. The rate of symptomatic knee OA was significantly lower in smokers and those walking more than 2 h per day. Female sex was also strongly associated with OA DIP joints. OA of DIP joints was found significantly associated with symptomatic knee OA. The latter is a major health problem in the elderly population, especially in about one fourth of women aged 50 years or over. These data suggest that advanced age, female sex, and type of residence are risk factors.