A Cox proportional hazard regression analysis was carried out that evaluated age-specific death risk among 21,890 twins born in Sweden during 1886 through 1925 and followed during 1962 through 1980. Cotwin's survival was used as the primary covariable, and auxiliary covariables were smoking, marital status and, among men, police registration for alcohol abuse. In each age, sex and zygosity group, except the oldest DZ males, cotwin's mortality had a significant, independent, positive relationship to the mortality risk of the individual. The auxiliary covariables, except marital status among females, had significant, independent, positive relationships to mortality among the youngest twins of both zygosity groups and in the middle age group of MZ twins. In the oldest age group, the death of MZ cotwins was the only variable significantly related to the individual's mortality. Heritability estimates for the age-specific probability or death risk, developed by different methods for different analysis groups, range between 0.4 and 0.6. They have reasonable internal consistency, are not much affected by the covariates, and are in agreement with other studies that did not control covariates.
The purpose of this study was to investigate the influence of physical activity and other factors on the mood of former elite male athletes and controls of middle and old age. The subjects were 664 former athletes and 500 controls who answered questionnaires in 1985 and 1995. The dependent variables depressive and anxiety symptoms were assessed by the shortened anxiety and depression scales of the BSI-53. Logistic regression was used for longitudinal as well as cross-sectional analyses to estimate odds ratios for symptoms of depression and anxiety in relation to leisure physical activity adjusted for age in 1995, sports group, personality characteristics, alcohol use, smoking, marital status, life events and socio-economic status. In the longitudinal analysis, low levels of physical activity as well as neuroticism, dissatisfaction, marital status, life events and social class in 1985 increased the risk of depression in 1995. Also physical activity has a protective effect against depressiveness; an increase of one MET-unit (hour/day) statistically significantly decreased the risk of depressiveness by 8 %. In the longitudinal analysis, physical activity had no significant association with anxiety. Cross-sectional analysis for depressive symptoms in 1995, but not for anxiety found associations with sports group and physical activity as well as alcohol use and marital status. Very high physical activity has a significant protective effect against depression.
In this paper a study of the distribution of mortality rates by social class and marital status for men and women in three age groups (25--44, 45--64 and 65--84) is presented. Natural and violent causes of death are analysed separately. The death certificates of Finnish citizens for the years 1969, 1970 and 1971 (totalling 137780) were analysed and mortality rates standarized using as reference population the data from the 1970 census. It is shown that certain combinations of social class and marital status can be considered as significant risk factors for mortality in the Finnish population.
The effect of social factors on the male/female difference in mortality in Finland was studied by comparing age-adjusted mortality of males and females by social class and marital status. 44,548 death certificates (years 1969-1971) and 1970 census data for 25-64-years olds were analysed. The gender difference was 2.8-fold: 5.3-fold for violent causes and 2.3-fold for natural causes. The greatest gender difference from violent causes was found in accidental poisonings (18.7-fold) and drownings (12.8-fold), and from natural causes in mental disorders (mainly alcoholism; 5.7-fold) and in ischemic heart disease (4.5-fold). The gender difference was most prominent in unskilled workers, divorced and widowed and less prominent in married and upper professionals. The great variation of gender difference of mortality by social class and marital status seems to indicate that mortality difference between males and females is associated to external factors rather than biological differences between men and women. This conclusion is also supported by the progressive increase of gender difference of mortality from 1.4 to 2.8 during the last 80 years in working-aged Finns.