[The influence of types of living alone on 2-year health changes according to elderly adults' marital status: Based on the Comprehensive Regional Studies for Preventing Isolation of the Elderly Who Live in Metropolitan Area (CAPITAL Study)].

Objectives　The aim of this research is to classify elderly adults who live alone by their marital status type and to clarify how those types affect their higher-level functional capacity and mental health with a 2-year follow-up survey.Methods　This research is based on the results from a survey in 2013. The base-line scores were from 757 participants who completed a survey by mail, carried out in B area of A ward, Tokyo, within the jurisdiction of community general support centers, with people who were not at nursing care levels 4 or 5 and who were not residents of welfare facilities. This study analyzed data for 517 of 527 participants, who answered all questions in the 2015 survey and indicated their marital status. This research categorized the respondents into 4 types of marital status: separation, divorce, bereavement, and unmarried groups. This study adopted the Tokyo Metropolitan Institute of Gerontology Index of Competence (TMIG-IC) as the index of higher-level functional capacity, and the WHO-Five Well-Being Index (WHO-5-J) as the mental health index. In the analysis of the causes of 2-year variations in TMIG-IC total scores and WHO-5-J scores, the dependent variable was each variation. This study used an analysis of covariance in which the fixed factors were types of living alone, sex, annual income, and having children who lived separately in the 2013 survey, and the covariance comprised the base-line scores for the dependent variables, age, and chronic diseases in the 2013 survey.Results　With regards to the variation in TMIG-IC total scores, main effects of the types of living alone were observed. The adjusted variation of covariance decreased most in the separation group (-0.95). For the variation in WHO-5-J scores, main effects of the types of living alone were indicated. In the divorce group, the adjusted variation of covariance was significantly higher than for the unmarried group (2.33 vs. -0.55).Conclusion　The results revealed that the types of marital status: separated, divorced, bereaved, and unmarried, affect changes in the higher-level functional capacity and mental health status of elderly adults living alone, 2 years later. Thus, although previously regarded as a single category, types of marital status should be considered in the analysis of elderly adults who live alone.