Table 2.
Hazard ratios for frailty status and all-cause mortality calculated using multivariate Cox proportional hazards analysis.
| n | Event | PY | Event/1000 PY | Model 1a | Model 2b | ||||
|---|---|---|---|---|---|---|---|---|---|
| Rate | 95%CI | HR | 95%CI | HR | 95%CI | ||||
| FSI × KCL | |||||||||
| Non-frailty | 5960 | 346 | 30,677 | 11.3 | (10.2 to 12.5) | 1.00 | (Ref) | 1.00 | (Ref) |
| Physical frailty | 223 | 14 | 1146 | 12.2 | (7.2 to 20.6) | 1.05 | (0.62 to 1.80) | 0.99 | (0.58 to 1.70) |
| Comprehensive frailty | 2211 | 367 | 10,792 | 34.0 | (30.7 to 37.7) | 2.02 | (1.74 to 2.36) | 1.91 | (1.63 to 2.23) |
| Combinations | 1882 | 530 | 8368 | 63.3 | (58.2 to 69.0) | 3.16 | (2.72 to 3.66) | 2.85 | (2.44 to 3.22) |
| Interaction | |||||||||
| RERIc | 28.4 | (22.1 to 34.7) | 1.08 | (0.45 to 1.71) | 0.95 | (0.33 to 1.57) | |||
| RERI (%) | 54.6 | 50.0 | 51.3 | ||||||
| FSI | |||||||||
| Non-frailty | 8171 | 713 | 41,469 | 17.2 | (16.0 to 18.5) | 1.00 | (Ref) | 1.00 | (Ref) |
| Physical frailty | 2105 | 544 | 9514 | 57.2 | (52.6 to 62.2) | 2.07 | (1.84 to 2.34) | 1.89 | (1.67 to 2.13) |
| KCL | |||||||||
| Non-frailty | 6183 | 360 | 31,823 | 11.3 | (10.2 to 12.5) | 1.00 | (Ref) | 1.00 | (Ref) |
| Comprehensive frailty | 4093 | 897 | 19,161 | 46.8 | (43.8 to 50.0) | 2.51 | (2.20 to 2.86) | 2.30 | (2.00 to 2.63) |
CI confidence interval, FSI frailty screening index, HR hazard ratio, KCL kihon checklist, RERI relative excess risk due to interaction, PY person-years.
aModel 1: Adjusted for age, sex, and population density.
bModel 2: In addition to the factors listed in Model 1, adjusted for family structure, economic status, educational attainment, smoking status, alcohol consumption status, sleep time, medication use, and number of chronic diseases.
cWe estimated that p < 0.05 when the 95% CI of the RERI exceeded 0, and p ≥ 0.05 when the 95% CI of the RERI did not exceed 0.