The study aimed to apply the frailty index (FI) to assess frailty status among Chinese centenarians and analyse its associated factors.

The study was a cross-sectional study.

The study included 1043 centenarians (742 females and 301 males) aged ≥100 years from the 2018 wave of the China Longitudinal Healthy Longevity Survey.

All participants were assessed for frailty by the FI. Basic characteristics, including age, height, weight, calf circumference, waist circumference, hip circumference, sex, years of education, financial status, exercise, fall status, coresidence, smoking, alcohol consumption, number of natural teeth, denture use, toothache, and tooth brushing, were collected. Multivariate logistic regression was used to analyse the associations between risk factors and frailty.

The average age of the participants was 102.06±2.55 years (range: 100–117 years). The FI ranged between 0.00 and 0.63. The mean FI for all participants was 0.27±0.13 (median 0.25; interquartile range 0.20–0.35). Participants were divided into quartiles. The number of natural teeth and denture use, coresidence, sex, exercise, and financial status showed significant associations with frailty classes (all P<0.05). Multivariate logistic regression analysis indicated that having ≤20 natural teeth without dentures (OR, 95% CI= 1.89(0.004–1.246), P<0.05), having ≤20 natural teeth with dentures (OR, 95% CI=2.21(0.158,1.432), P=0.015), living alone or in an institution (OR, 95% CI=1.68(0.182–0.849), P=0.002), lacking exercise (OR, 95% CI=2.54(0.616–1.246), P<0.001), having insufficient financial resources (OR, 95% CI=2.9(0.664–1.468), P<0.001), and being female (OR, 95% CI=1.47(0.137,0.634), P=0.002) were independent risk factors for frailty.

Chinese centenarian women are frailer than men. Having fewer natural teeth, living alone or in an institution, lacking exercise, and having insufficient financial resources were the factors associated with frailty among Chinese centenarians. Family conditions and healthy lifestyles may be important for frailty status in centenarians.