Table 1 List of variables in the Clinical Frailty-Deficit Count (CF-DC) index

Lifestyle-related variables

Low education level (≤ 6 y), living alone, residence on the 2nd floor and above without elevator, no one can help you when you are in need, lack of social activities, smoking, alcohol intake, no regular exercise

Health status- and healthcare-related variables

Hypertension, diabetes mellitus, hyperlipidemia, cerebrovascular disease, cardiovascular disease, chronic lung disease, liver disease, renal and urinary disorder, cancer, sleep disorder, neurodegenerative disorder, thyroid disease, gastrointestinal disease, hematological disease, bone and joint disease, osteoporosis, spondylopathy, rheumatic disease, gout, visiting ≥ 4 different specialists, polypharmacy (≥ 8 drugs), fall in the past year, not positively accepting medical healthcare, unable to take care of yourself, unable to make medical decisions by yourself, systolic blood pressure > 140 mmHg, diastolic blood pressure > 90 mmHg, pulse rate > 96/min, oxygen saturation < 95%

Nutrition- and sarcopenia-related variables

Have nutritional problems, weight loss > 3 kg within the last year, missing teeth, BMI < 18.5 or > 24 kg/m2, appendicular skeletal muscle index < 7.0 or < 5.7 in men and women, handgrip strength < 28 or < 18 kg in men and women, walking speed < 1 m/s, 5 times sit-to-stand test > 12 s, Time Up and Go Test < 10 s, Time Up and Go Test < 0.3 m/s

Cognition-, mood-, and spirituality-related variables

Poor memory, difficulty in learning, difficulty in communication, poor judgment, forget correct date, feel unhappy, loss of interest, feel that your life is empty, have a fear of death, feel hopeless, cannot accept the physiological change of body due to aging, cannot accept the change of life after retirement, with no religion, did not sign DNR

Functional status-related variables

Hearing impairment, visual impairment, cannot dress by yourself, cannot eat by yourself, cannot get up from bed, stand and sit on the chair by yourself, cannot go to the toilet by yourself, cannot take bath by yourself, cannot buy personal item by yourself, cannot do housework at home, cannot manage money, cannot make phone calls/ ride bus on your own, difficulty in walking ≥ 100 m, difficulty in climbing ≥ 10 stairs, decreased mobility and need the assistance of a cane, poor balance, fatigue, low physical activities, fell everything you did was an effort or could not get going