The Catalonia Study
The Catalonia Study consists of two cohorts sampled from representative surveys from the central area of Catalonia and part of the metropolitan area of Barcelona, Spain. The first stage drew a random sample of individuals from nine municipalities with probability proportional to population size. In the second stage, a random sample of men and women from the Municipal population registries were used as the sampling frame, from each municipal population register, a random sample stratified by sex and ten-year age groups, 25-64 years, of fixed number was selected. Baseline examinations were carried out in 1986-1988 for cohort 1 (Round 1) of N=2,571, response rate was 74%. Cohort 2 (Round 1) was collected in 1990-1992 (N=2,936), response rate was 67%. Participants were mainly from the Industrial and services economy (17, 18, 19). All subjects gave informed consent. The project was approved by the Institute of Health Studies steering committee. Follow up until 1997 for Cohort 1 and until 1999 for Cohort 2 was achieved through follow up questionnaires and record linkage with MONICA registers, national mortality index register and hospital discharge registers.