Long-term predictors of survival for the Seven Countries Study cohort from Crete: from 1960 to 2000

BACKGROUND: In 1960, all male inhabitants of a series of villages in rural Crete, born between 1900 and 1919, were invited to participate in the Seven Countries Study. Analysis of 25-year mortality data from the 16 cohorts of participants indicated that the cohort from Crete had the lowest age-standardised all-cause and coronary heart disease death rates. METHODS: At baseline, 686 Cretan men (98% of those invited) participated in health examinations. Mortality data were collected over 40 years. Time-fixed and updated covariate survival analysis techniques were applied to assess eight cardiovascular disease risk factors as long-term predictors of all-cause and cardiovascular disease mortality. RESULTS: The median survival time was 32 years. All-cause and cardiovascular mortality rates were 26 and 11 per 1000 person-years, respectively. Age (relative risk 1.11, 95% CI 1.09-1.13), diastolic blood pressure (relative risk 1.02, 95% CI 1.01-1.03), and smoking (relative risk 1.37, 95% CI 1.14-1.64) were positively associated and forced expiratory volume (relative risk 0.50, 95% CI 0.36-0.68) was negatively associated with all-cause mortality. Age (relative risk 1.13, 95% CI 1.09-1.16), diastolic blood pressure (relative risk 1.01, 95% CI 1.001-1.03), and forced expiratory volume (relative risk 0.53, 95% CI 0.32-0.89) were independent predictors of cardiovascular mortality. Serum cholesterol concentration and body mass index were not independently associated with death risk. CONCLUSIONS: The Cretan cohort displays favourable 40-year survival. Even so, long-term predictors of the hazard of both all-cause and cardiovascular disease mortality are present.