Validity of Total Kihon Checklist Score for Predicting the Incidence of 3-Year Dependency and Mortality in a Community-Dwelling Older Population

Objectives

To validate the ability of the total Kihon checklist (t-KCL) score to predict the incidence of dependency or death within 3 years in a community-dwelling older population.

Design

Population-based longitudinal observational study.

Setting

Town of Higashi-ura, Japan.

Participants

A total of 5542 independent seniors who were residents in the town of Higashi-ura.

Measurements

The KCL questionnaire was sent to independent older residents. Based on our previous report, those with a t-KCL score of 0-3 were classified as robust, 4-7 as pre-frail, and 8 + as frail. The incidence of dependency or death was observed over 3 years. Dependency was defined as a new certification for long-term care insurance (LTCI) service need. Information regarding LTCI certification or death was obtained from the municipal government.

Results

Of 8091 independent older adults, 5542 seniors completed the KCL questionnaire. Based on the t-KCL score, they were classified into 3 groups: 2962 (53.4%) as robust, 1625 (29.3%) as pre-frail, and 955 (17.2%) as frail. Over the 3 years, 510 seniors (9.2%) had new LTCI certifications and 170 (3.1%) died. Cox regression analysis adjusted for age and sex showed that the classification of frailty status by t-KCL score was significantly associated with the incidence of dependency both in the pre-frail and the frail hazard ratios (HRs): 2.027 and 4.768; 95% confidence intervals (CIs): 1.575-2.608 and 3.733-6.089, respectively]. On the other hand, the ability to predict death was significant, but only in the frail group (HR: 2.830; 95% CI: 1.952-4.104).

Conclusion

The classification of frailty status by t-KCL score could be a significant tool to predict the incidences of dependency and mortality in older adults.