Kokubu Keiko, Horiguchi Minako, Mori Toru
NPO Japan Dementia Prevention Research Institute.
Takasaki University of Health and Welfare.
Nihon Koshu Eisei Zasshi. 2020;67(5):319-326. doi: 10.11236/jph.67.5_319.
Objectives This study aimed to observe the life prognosis of persons with dementia during the first five years after registering for long-term care insurance, and to determine the factors affecting their prognosis.Methods A total of 556 persons, aged 65 years or older newly registered for long-term care insurance in a city in Japan, were observed. The life prognosis of the registered persons was determined using standardized mortality ratio (SMR) with the general population as a standard, and relevant factors were observed in terms of dependence indices of dementia and disability.Results The mean age of persons newly registered for long-term care insurance was 81.6 years and 63% of them were females. Mortality during the first 4.5 years after registration was 16.7% p.a., with males and those of older age having higher rates. The SMR was 1.80 for all individuals, with males and those of younger age having a higher SMR. The SMR increased with the severity of the disability (higher classes on the disability dependence index) at the time of the registration, while no significant trend was seen in SMR with the dementia dependence index. Multivariate analysis revealed that mortality was dependent on sex (male>female), age (older>younger), disability dependence indices (higher classes>lower classes), and current place of residence (home>facility), while there were no significant trends found in mortality with degree of severity on the dementia dependence indices. The adjusted odds ratios of dying from respective factors were as follow: from sex (male/female, with male as a standard) 0.35 (95% confidence interval 0.24-0.51), from age group (65-74 years/75-84/85+, stepwise with 65-74 years as a standard) 1.84 (1.39-2.47), from disability dependence index (normal/I/Ⅱa/Ⅱb..., stepwise with "normal" as standard) 1.38 (1.21-1.58), and from place of residence (home/facility, with home as a standard) 0.64 (0.42-0.99). When limited to only the elderly with dementia dependence indices of Ⅱa-Ⅳ, the analysis showed similar results.Conclusion Elderly persons registered for long-term care insurance had higher mortality rates than the general population that was dependent on the disability dependence index, but not on the dementia dependent index. Further studies are therefore necessary to elucidate the factors relevant to the study's finding.
目的 本研究旨在观察痴呆症患者在登记长期护理保险后的头五年内的生命预后，并确定影响其预后的因素。
方法 观察了日本某市新登记长期护理保险的556名65岁及以上的人员。以普通人群为标准，使用标准化死亡率（SMR）确定登记人员的生命预后，并从痴呆症和残疾的依赖指数方面观察相关因素。
结果 新登记长期护理保险的人员平均年龄为81.6岁，其中63%为女性。登记后前4.5年的死亡率为每年16.7%，男性和年龄较大者的死亡率较高。所有个体的SMR为1.80，男性和年龄较小者的SMR较高。登记时SMR随残疾严重程度（残疾依赖指数等级较高）增加，而SMR与痴呆症依赖指数无明显趋势。多因素分析显示，死亡率取决于性别（男性>女性）、年龄（年龄较大>年龄较小）、残疾依赖指数（等级较高>等级较低）和当前居住地点（家中>机构），而死亡率与痴呆症依赖指数的严重程度无明显趋势。各因素导致死亡的调整比值比如下：性别（男性/女性，以男性为标准）0.35（95%置信区间0.24 - 0.51），年龄组（65 - 74岁/75 - 84岁/85岁及以上，以65 - 74岁为标准逐步）1.84（1.39 - 2.47），残疾依赖指数（正常/I/Ⅱa/Ⅱb……，以“正常”为标准逐步）1.38（1.21 - 1.58），居住地点（家中/机构，以家中为标准）0.64（0.42 - 0.99）。当仅限于痴呆症依赖指数为Ⅱa - Ⅳ的老年人时，分析显示结果相似。
结论 登记长期护理保险的老年人死亡率高于普通人群，其死亡率取决于残疾依赖指数，而非痴呆症依赖指数。因此，有必要进一步研究以阐明与本研究结果相关的因素。
