Table 2.
Comparison of Claims-Based Frailty Measures for Identifying Frailty and Prevalent Disability in the Health and Retirement Study
| Index | Frailty Category (Percentile Distribution) | Spearman Correlation (Partial Correlationa) | C-statistic (ΔC-statisticb) | ||||
|---|---|---|---|---|---|---|---|
| Robust (≤10th) | Well (11–25th) | Vulnerable (26–75th) | Frail (76–90th) | Very Frail (>90th) | |||
| Frailty phenotype,cn (%) | |||||||
| Davidoff index | 21 (8.0) | 26 (6.8) | 182 (14.5) | 48 (21.1) | 62 (41.3) | NA | 0.73 (0.04) |
| Faurot index | 15 (5.9) | 26 (6.9) | 133 (11.3) | 88 (28.1) | 77 (53.1) | NA | 0.74 (0.06) |
| Segal index | 8 (3.3) | 23 (6.2) | 156 (13.5) | 69 (21.0) | 83 (48.0) | NA | 0.73 (0.05) |
| Kim index | 8 (2.9) | 26 (7.2) | 148 (12.6) | 79 (25.8) | 78 (51.0) | NA | 0.78 (0.09) |
| Frailty index, mean (SD) | |||||||
| Davidoff index | 0.17 (0.10) | 0.15 (0.10) | 0.19 (0.12) | 0.21 (0.14) | 0.33 (0.17) | 0.22 (0.18) | NA |
| Faurot index | 0.13 (0.08) | 0.15 (0.10) | 0.17 (0.11) | 0.26 (0.13) | 0.37 (0.16) | 0.45 (0.32) | NA |
| Segal index | 0.12 (0.10) | 0.14 (0.10) | 0.19 (0.12) | 0.24 (0.14) | 0.31 (0.15) | 0.40 (0.26) | NA |
| Kim index | 0.10 (0.08) | 0.13 (0.09) | 0.18 (0.11) | 0.27 (0.12) | 0.37 (0.15) | 0.59 (0.55) | NA |
| Any ADL dependence, n (%) | |||||||
| Davidoff index | 19 (3.7) | 34 (4.5) | 233 (8.0) | 71 (18.1) | 256 (50.5) | NA | 0.79 (0.09) |
| Faurot index | 12 (2.3) | 26 (3.3) | 168 (6.7) | 128 (17.5) | 279 (55.0) | NA | 0.80 (0.10) |
| Segal index | 18 (3.0) | 36 (4.7) | 229 (9.4) | 136 (17.9) | 194 (38.3) | NA | 0.74 (0.04) |
| Kim index | 12 (2.3) | 83 (6.6) | 128 (6.3) | 132 (17.4) | 258 (50.8) | NA | 0.81 (0.11) |
| Two or more ADL dependencies, n (%) | |||||||
| Davidoff index | 3 (1.0) | 8 (1.7) | 48 (2.9) | 25 (7.2) | 70 (22.6) | NA | 0.79 (0.12) |
| Faurot index | 6 (1.9) | 17 (3.6) | 86 (5.6) | 57 (12.3) | 125 (40.3) | NA | 0.81 (0.14) |
| Segal index | 5 (1.6) | 6 (1.3) | 56 (3.6) | 38 (8.2) | 49 (15.9) | NA | 0.73 (0.06) |
| Kim index | NRd | 6 (1.3) | 34 (2.2) | 34 (7.3) | 80 (25.8) | NA | 0.84 (0.17) |
| Number of ADLs requiring help, mean (SD) | |||||||
| Davidoff index | 0.06 (0.38) | 0.08 (0.42) | 0.17 (0.70) | 0.51 (1.30) | 1.78 (2.19) | 0.30 (0.28) | NA |
| Faurot index | 0.04 (0.33) | 0.06 (0.36) | 0.14 (0.64) | 0.43 (1.16) | 1.87 (2.18) | 0.35 (0.28) | NA |
| Segal index | 0.07 (0.46) | 0.08 (0.45) | 0.23 (0.89) | 0.50 (1.30) | 1.24 (1.95) | 0.27 (0.16) | NA |
| Kim index | 0.06 (0.49) | 0.16 (0.73) | 0.13 (0.61) | 0.45 (1.23) | 1.66 (2.09) | 0.31 (0.27) | NA |
Notes: ADL = activity of daily living; NR = not reported; SD = standard deviation.
aPartial correlation coefficient was estimated after adjusting for age and sex;
bC-statistics for age and sex alone were 0.68 for frailty phenotype, 0.70 for any ADL dependence, and 0.69 for ≥2 ADL dependencies;
cFrailty phenotype was not available in 1,523 individuals due to missing gait speed or grip strength;
dThe cell size fewer than 3 was not reported.