Physical activity and mortality of 75-year-old people in three Nordic localities: a five-year follow-up.

The purpose of this 5-year follow-up study was to investigate the relationship between physical activity and mortality in persons aged 75 in three Nordic localities. The study is part of the common NOrdic Research project on Ageing (NORA). The samples consisted of 221 men and 259 women in Glostrup, Denmark, 159 men and 209 women in Göteborg, Sweden, and 119 men and 236 women in Jyväskylä, Finland. Physical activity was measured with a self-report questionnaire, from which a dichotomous explanatory variable was created for the subsequent analysis. Covariates examined in this study were smoking, use of alcohol and the presence of cardiovascular diseases. Baseline measurements were conducted in Glostrup and Jyväskylä in 1989, and a year later in Göteborg. Mortality data was collected from the mortality registry in each country. The follow-up period was 5 years. Fisher's exact test, Cox regression and Kaplan-Meier survival analysis were used in the statistical analysis of the data. The results showed that when physical activity alone was considered, inactivity was associated with an increased mortality risk in all groups except for the men in Jyväskylä. Of the covariates, only smoking and cardiovascular diseases were found to be associated with increased mortality risk and only among the women in Göteborg and Jyväskylä, respectively. When the effect of physical activity on mortality was analyzed together with the covariates, the relationship between physical inactivity and increased mortality risk remained significant in all groups except for the men in Jyväskylä. In addition to this, smoking remained a significant predictor of mortality for women in Göteborg, and the effect of cardiovascular diseases for women in Jyväskylä was nearly significant. The results showed that being physically active predicted survival for persons aged 75 during the follow-up period in all three localities.