THE RELATION OF CHRONIC DISEASES TO ALL-CAUSE MORTALITY RISK - THE 7 COUNTRIES STUDY

The relation of chronic conditions on all-cause mortality in populatio n samples was studied based on observations from the Seven Countries S tudy. The objective of this work was to study the risk of death during a 15-year follow-up of middle-aged men in relation to six chronic dis eases. Fifteen cohorts of men aged 50-69, totalling 8122 subjects, wer e examined around 1970 in seven countries: Finland, The Netherlands, I taly Croatia (former Yugoslavia), Serbia (former Yugoslavia), Greece a nd Japan. Clinical diagnoses findings were made for coronary heart dis ease (CHD), 'other heart diseases' (OTH), peripheral arterial disease (PAD), stroke (STR), chronic obstructive pulmonary disease (COPD), and diabetes mellitus (DIAB). All-cause mortality was assessed in the sub sequent 15 years. Death rates and relative risks were estimated from c rude data, and in proportional hazards models after adjustment for age , systolic blood pressure and serum cholesterol level, cigarette smoki ng and body mass index. Large regional differences were found in the p revalence of the six conditions. Weak relations were found between pop ulation prevalence of each disease and population death rates for that disease. Among cohorts the relative risk of death in 15 years from an y cause, adjusted for other risk factors, showed little variation amon g countries. Pooled relative risks, adjusted by the inverse of varianc e (with 95% CI) were: for CHD, 1.81 (1.60-2.06); for OTH, 1.47 (1.28-1 .69); for PAD, 1.64 (1.39-1.93); for STR, 1.56 (1.23-1.98); for COPD, 1.67 (1.48-1.88); and for DIAB, 1.75 (1.43-2.15). The smallest variabi lity of prognosis among countries was found for CHD, OTH and DIAB; the largest for PAD, STR and COPD. Despite simple clinical diagnostic pro cedures and large differences in prevalence, the relation of establish ed prevalent conditions to subsequent all-cause mortality is relativel y uniform among countries and across these conditions, with a relative risk of dying in 15 years usually ranging between 1.5 and 2.0.