Table 1.

Baseline Characteristics of the Study Participants by Frailty Status Transitions From Baseline to the Second Resurvey

	Baseline Robust		Baseline Prefrail
	Remained	Worsening	Remained or Regression	Worsening
N (%)	9 756 (39.3)	7 916 (31.9)	6 297 (25.4)	844 (3.4)
Sociodemographic factors
Age, year (SD)	47.8 (9.1)	52.6 (10.0)	54.6 (10.0)	59.1 (8.5)
Women, %	61.0	61.3	62.4	67.8
Urban area, %	43.3	44.6	40.1	50.5
Middle school and higher, %	49.2	45.8	46.7	46.0
Lifestyle factors
Male participants: daily smokinga, %	64.5	70.2	69.1	70.6
Female participants: daily smoking, %	2.8	2.2	2.6	3.6
Male participants: heavy alcohol drinkingb, %	22.0	25.4	25.3	23.6
Female participants: heavy alcohol drinking, %	2.2	1.9	2.3	2.5
Eating fruit and vegetables daily, %	18.8	16.1	16.3	14.5
Physical activity, MET-h/d	21.9	21.7	20.7	20.6
BMI < 18.5 kg/m2, %	3.8	3.7	4.2	3.2
BMI ≥ 24.0 kg/m2, %	40.5	47.0	46.3	52.4
WHR ≥ 0.90 (men) or 0.85 (women), %	52.1	58.8	58.4	63.3
Medical history, %
Hypertension	21.3	31.7	53.3	56.0
Heart disease	0.6	1.1	5.6	8.6
Stroke or transient ischemic attack	0.2	0.3	2.2	2.3
Emphysema or bronchitis	0.4	0.9	5.3	11.6
Tuberculosis	0.2	0.7	2.3	2.4
Asthma	0.1	0.2	0.9	3.5
Peptic ulcer	2.0	2.3	8.9	8.1
Gallstone diseases	2.2	4.2	11.6	13.0
Rheumatoid arthritis	0.8	1.1	5.0	6.2
Fracture	3.8	4.8	13.9	14.4
Neurasthenia	0.2	0.4	3.2	4.8
Diabetes	1.0	2.8	10.0	14.8
Cancer	0.2	0.1	0.8	1.8
Chronic kidney disease	0.5	0.8	2.6	2.3

Notes: BMI = body mass index; MET = metabolic equivalent task; WHR = waist-to-hip ratio. Baseline characteristics were adjusted for age, sex, and 10 study area, except for these 3 variables.

^aThose who stopped smoking due to illness were classified as daily smoking.

^bHeavy alcohol drinking refers to current drinking ≥30 g/d of pure alcohol in men or ≥15 g/d in women or ex-drinkers.