Psychosocial risk factors and mortality: a prospective study with special focus on social support, social participation, and locus of control in Norway.

STUDY OBJECTIVE: The objective is to investigate the effect on mortality of psychosocial variables, with special focus on social support, social participation, and locus of control. DESIGN: The study is designed as a prospective study with a 17 year follow up period, using univariate and multivariate proportional hazards regression analysis to estimate the predictive power of psychosocial variables, when controlling for sociodemographic and biological factors. SETTING: The study is based on a population sample randomly drawn from different neighbourhoods of Oslo in 1975/76, for the purpose of surveying health, in particular mental health, in relation to various social and psychosocial variables. The initial data were gathered by structured interviewing, whereas the data about mortality and cause of death, was gathered from the Central Bureau of Statistics. PARTICIPANTS: The initial sample included 1010 persons above the age of 18 years, with no upper age limit. The follow up with respect to mortality covered the whole sample, with the exception of a very few who had left the country. MAIN RESULTS: When controlling for socio-demographic and biological factors, low social participation, and to a lesser extent, few close relationships and external locus of control, were associated with increased mortality. CONCLUSION: The effect of social participation and locus of control may indicate that life style, and individual psychological resources, are at least as important for survival as support from others in stressful life situations.