WHO-ILAR COPCORD study (stage 1, urban study) in Sanandaj, Iran.

This study aims to conduct an urban Community Oriented Program for Control Of Rheumatic Diseases (COPCORD) study in Sanandaj (Kurdistan, Iran). Sanandaj with a population of 311,446 (2006 census), Caucasian of Kurdish subgroup, was selected as the field. Sanandaj was divided into 100 clusters and subjects were randomly selected from them (50 subjects from each cluster).