Objectives: The aim of this study was to develop a Fried Frailty Phenotype Questionnaire (FFPQ) and a Japanese FRAIL (fatigue, resistance, ambulation, illnesses, and loss of weight) scale (FRAIL-J) and to evaluate the reliability and validity of both questionnaires in Japanese community-dwelling older adults.
Design: Cross-sectional analysis of Itoshima Frail Study (IFS).
Setting: The IFS is an ongoing community-based prospective study in Itoshima (Japan).