A Lifestyle Behavior Score Predicting Cardiovascular and Other Causes of Death in a Cohort of Middle-Aged Men Followed up Until Extinction

Objective: To create and test in a population study a behavior score, using as far as possible, procedures based on the a posteriori approach. Material and Methods: Data from the Italian Rural Areas (IRAs) of the Seven Countries Study of Cardiovascular Diseases (SCS), comprising 1712 middle-aged men enrolled in 1960 and their entry levels of smoking habits, physical fitness and dietary habits, were entered into a Principal Components Analysis, producing an individual overall behavior (factor) score. The end-points were the 62-year follow-up, approaching cohort extinction, mortality for all-cause death and five cause-specific conditions, which formed the dependent variables of a series of Cox models, whose outcome was expressed by hazard ratios for one class increase in the score, and comparing tertile 1 versus tertile 3 of the score, without and with the addition of age, systolic blood pressure, serum cholesterol and high socio-economic status as possible confounders. Results: Fatal coronary heart disease (CHD), heart diseases of uncertain etiology (HDUE), stroke, cancer (CAN), chronic bronchitis (CB) and all-cause mortality (ALL) were predicted in a significant way in the four approaches, with a relevant reduction in death rates expressed by hazard ratios ranging from 0.42 to 0.83. Moreover, the influence of the three basic behavior scores showed that CHD was the most strongly associated with them. Age at death for all-cause mortality, on the other hand, was directly related with the full and the three types of behavior score. Conclusions. A behavior score based on three common lifestyle habits created by an a posteriori approach proved to be significantly associated with various causes of death in a male population group followed-up until extinction.