[Depression and the risk of long-term care insurance certification: the Tsurugaya project].

OBJECTIVE: The purpose of this study was to examine the relationship between depressive status and subsequent certification of long-term care insurance use, and to investigate sex differences in this relationship in an elderly Japanese population. METHODS: The Tsurugaya Project was a comprehensive geriatric assessment conducted for community-dwelling elderly persons aged 70 years or older in the Tsurugaya area, Sendai, Japan (N = 2,925). Of those who participated (N = 958), the 841 who gave informed consent and were not qualified for certification of long-term care insurance use at the baseline survey were analyzed. Depression was asessed using the 30-item Geriatric Depression Scale (GDS). We classified the subjects into three categories: normal (GDS less than 10), mild depression (GDS between 10 and 13), and moderate to severe depression (GDS more than 13 and/or taking antidepressive medication). The hazard ratio of incident certification of long-term care insurance use by depressive status was calculated using the Cox proportional hazards model. RESULTS: During 4 years of follow-up, a total of 151 subjects were certificated for long-term care insurance and 46 subjects died. Particularly in men, the depressive status was related to subsequent incident certification of long-term care insurance use. In men, the age-adjusted hazard ratios (HRs) were 1.77 (95% confidence interval (CI): 0.91-3.48) for mild depression, and 2.26 (1.11-4.64) for moderate to severe depression (P for trend = 0.023). The relationship between depressive status and subsequent certification of long-term care insurance use in men was significant even after adjustment for age, comorbid conditions, social factors and lifestyle (multivariate-adjusted HR: 1.31 (95% CI: 0.65-2.65); mild depression 2.19 (1.06-4.54); moderate to severe depression: P for trend= 0.034). In women, there was no significant association between depressive status and certification of long-term care insurance use. In both sexes, there was no significant association between depressive status and death. CONCLUSION: The relationship between depressive status and subsequent certification of long-term care insurance use was significant only in men. In men, the relationship was significant even after adjustment for age, comorbid conditions, social factors and lifestyle. These results suggest a sex difference in the relationship between depressive status and subsequent certification of long-term care insurance use in elderly Japanese.