Prognostic significance of the Questionnaire for Medical Checkup of Old-Old for the incidence of functional disability: The Shizuoka Kokuho Database study

AIM: In the Japanese health checkup system for older adults aged ≥75 years, the Questionnaire for Medical Checkup of Old-Old (QMCOO) was adopted after 2020. However, the prognostic significance of this questionnaire for the incidence of functional disability is uncertain. The current study aimed to validate the prognostic significance of the QMCOO, and to develop a simple risk score for functional disability by analyzing health insurance claims data including annual health checkup data. METHODS: This study included 111 282 older adults aged 75-90 years who did not receive long-term care services at baseline. The study period was between the earliest day of participation in the health checkup after April 2020 and September 2022. The participants who were certified as care level 2 and higher during this period were considered as incident cases of functional disability. RESULTS: Within a mean follow-up duration of 1.7 years (191 085 person-years), 4578 functional disability cases were identified. In addition to the basic covariates, among the 15 items in the QMCOO, nine were identified as independent determinants. The probability of developing functional disability that was calculated using the model was associated with older age, male sex, underweight and poor responses to the QMCOO items. According to the weighted score based on the model, the participants was classified as functional disability probability of <1% to >45%. CONCLUSIONS: The nine items in the QMCOO were associated with the incidence of functional disability. The weighted scoring system could be helpful for the use of the QMCOO. Geriatr Gerontol Int 2025; 25: 260-266.