To examine rural-urban differences in the relationships of sociodemographic, social network, and lifestyle factors to mortality in middle-aged men , we used the data from a community based prospective cohort study, the Komo-Ise study. The subjects were all men aged 40-69 years living in Komochi Village, the rural group (n=2,295), or the downtown district of Isesaki City, the urban group (n=3,334), as of 1993. They completed a self-administered questionnaire in 1993 and were followed for all-cause deaths until 2000. The Cox proportional hazards model was used to compute relative risks (RRs) with 95% confidence intervals (CIs). Low educated men and men without a spouse in the rural group had an increased risk of mortality (RR=4.4; 95%Cl: 1.1-18.2, RR=2.4; 95%Cl: 1.2-4.5). Men who did not enjoy good fellowship with their neighbors in the rural group had a decreased risk of mortality (RR=0.58; 95%Cl: 0.35-0.97). Mortality risks were significantly higher in urban men not participating in hobbies, club activities or community groups (RR=1.6; 95%Cl: 1.1-2.4). These variables remained significant risk factors, even after controlling for all sociodemographic, social network, lifestyle, and health status variables. Educational level, marital status and relation to neighborhoods showed significant rural-urban differences.J Epidemiol, 2002;12:93-104 rural-urban differences, sociodemographic factors, lifestyle, social networks, mortality
INTRODUCTIONThe dramatic shift in the major causes of disability and death from infectious to chronic diseases has made theories of disease etiology shift from a single factor to multiple factors including behavioral and environmental as well as biologic and genetic factors. Among these factors, many epidemiologists have focused on health behavior or lifestyle factors, such as smoking habit, overweight, alcohol consumption, physical inactivity and so on, for the past several decades 1-4). A number of prospective studies based on randomly selected cohort groups have indicated these to be the major determinants of premature and preventable disease and/or death 1-4). In addition to health behavior and lifestyle factors, poor social networks and social support have been recognized as independent risk factors for mortality 5-7), since Cassel8) hypothesized that psychosocial effects in the environment increased a person's resistance to risk factors.Among the earlier large investigations of the relationship between health and human ties, was the study performed in Alameda County, California. Berkman et al. 5) examined four social network sources: 1) marriage; 2) contacts with close friends and relatives; 3) church membership, and 4) informal and formal group associations. Their findings revealed social and community ties to be associated with mortality risk and each of the four sources to be a predicted risk factor for mortality independently from the other three. However, the Tecumseh Community Health Study 9) and the Evans County Cardiovascular Epidemiologic Study 10) results were not consiste...