Classification of frailty using the Kihon checklist: A cluster analysis of older adults in urban areas

Aim Frailty is an important predictor of the need for long‐term care and hospitalization. Our aim was to categorize frailty in community‐dwelling older adults. Methods The present study was carried out in 2011–2013, and consisted of 1380 individuals over 65 years of age. Participants completed the Kihon checklist, which is widely used to assess frailty in Japan, and their physical, cognitive and social function was evaluated. Non‐hierarchical cluster analysis was used to statistically categorize frailty. The optimum number of clusters was determined as the point at which the external reference values (instrumental activity of daily living score, grip power, 10‐m walk time, body mass index, portable fall risk index, occlusal force and Mini‐Mental State Examination score) differed. Results According to the Kihon checklist, 369 (26.7%) of the 1380 study participants were considered frail. When the cluster number was increased from two to six, the scores in each subdomain of the Kihon checklist significantly differed. The estimated minimum number of clusters was five, and each of the five cluster groups had distinct characteristics. The numbers of participants in cluster groups 1–5 were 105, 78, 62, 71 and 53, respectively. Conclusions We identified five types of frailty in community‐dwelling older adults in Japan: “experience of falling,” “pre‐frailty,” “oral frailty,” “housebound” and “severe frailty.” Geriatr Gerontol Int 2017; 17: 69–77.