Associations of ikigai as a positive psychological factor with all-cause mortality and cause-specific mortality among middle-aged and elderly Japanese people: findings from the Japan Collaborative Cohort Study.J Psychosom Res. 2009 Jul; 67(1):67-75.JP
To determine whether presence of ikigai as a positive psychological factor is associated with decreased risks for all-cause and cause-specific mortality among middle-aged and elderly Japanese men and women.
From 1988 to 1990, a total of 30,155 men and 43,117 women aged 40 to 79 years completed a lifestyle questionnaire including a question about ikigai. Mortality follow-up was available for a mean of 12.5 years and was classified as having occurred in the first 5 years or the subsequent follow-up period. Associations between ikigai and all-cause and cause-specific mortality were assessed using a Cox's regression model. Multivariate hazard ratios (HRs) were adjusted for age, body mass index, drinking and smoking status, physical activity, sleep duration, education, occupation, marital status, perceived mental stress, and medical history.
During the follow-up period, 10,021 deaths were recorded. Men and women with ikigai had decreased risks of mortality from all causes in the long-term follow-up period; multivariate HRs (95% confidence intervals, CIs) were 0.85 (0.80-0.90) for men and 0.93 (0.86-1.00) for women. The risk of cardiovascular mortality was reduced in men with ikigai; the multivariate HR (95% CI) was 0.86 (0.76-0.97). Furthermore, men and women with ikigai had a decreased risk for mortality from external causes; multivariate HRs (95% CIs) were 0.74 (0.59-0.93) for men and 0.67 (0.51-0.88) for women.
The findings suggest that a positive psychological factor such as ikigai is associated with longevity among Japanese people.