Table 3.
Multivariable Cox Regression Model of Factors Associated with IMN Breakage Among Patients in the Database from 2016 to 2019
| Parameters | Hazard Ratio | 95% Hazard Ratio Confidence Limits | p-value | |
|---|---|---|---|---|
| Age 18–50 (vs 75+) | 0.720 | 0.129 | 4.018 | 0.7082 |
| Age 50–64 (vs 75+) | 2.972 | 1.216 | 7.264 | 0.0169* |
| Age 65–74 (vs 75+) | 1.305 | 0.44 | 3.871 | 0.6319 |
| Employee (vs spouse/other) | 0.490 | 0.246 | 0.976 | 0.0424* |
| Comprehensive (vs PPO) | 0.628 | 0.235 | 1.678 | 0.3539 |
| HMO (vs PPO) | 0.895 | 0.325 | 2.464 | 0.8295 |
| Other (vs PPO) | 0.357 | 0.104 | 1.224 | 0.1014 |
| North Central (vs South) | 2.060 | 0.926 | 4.582 | 0.0763 |
| Northeast (vs South) | 1.054 | 0.399 | 2.786 | 0.9158 |
| West (vs South) | 0.986 | 0.311 | 3.121 | 0.9803 |
| Index year 2016 (vs 2019) | 0.522 | 0.162 | 1.68 | 0.2758 |
| Index year 2017 (vs 2019) | 0.791 | 0.260 | 2.403 | 0.6795 |
| Index year 2018 (vs 2019) | 1.034 | 0.351 | 3.047 | 0.9516 |
| Elx. Gr. 01 congestive heart failure | 1.917 | 0.465 | 7.898 | 0.3677 |
| Elx. Gr. 02 cardiac arrhythmia | 1.265 | 0.502 | 3.187 | 0.6186 |
| Elx. Gr. 03 valvular disease | 1.516 | 0.506 | 4.544 | 0.4574 |
| Elx. Gr. 04 pulmonary circulation disorders | 1.621 | 0.330 | 7.963 | 0.5519 |
| Elx. Gr. 05 peripheral vascular disorders | 1.226 | 0.334 | 4.501 | 0.7592 |
| Elx. Gr. 06 hypertension uncomplicated | 1.973 | 0.813 | 4.788 | 0.1328 |
| Elx. Gr. 07 hypertension complicated | 0.724 | 0.161 | 3.255 | 0.6736 |
| Elx. Gr. 08 paralysis | 6.136 | 0.419 | 89.888 | 0.1853 |
| Elx. Gr. 09 other neurological disorders | 0.342 | 0.072 | 1.619 | 0.1762 |
| Elx. Gr. 10 chronic pulmonary disease | 0.535 | 0.147 | 1.953 | 0.3438 |
| Elx. Gr. 11 diabetes uncomplicated | 0.329 | 0.089 | 1.220 | 0.0965 |
| Elx. Gr. 12 diabetes complicated | 2.793 | 0.666 | 11.703 | 0.1601 |
| Elx. Gr. 13 hypothyroidism | 1.778 | 0.806 | 3.922 | 0.1541 |
| Elx. Gr. 14 renal failure | 2.187 | 0.319 | 15.009 | 0.4260 |
| Elx. Gr. 16 peptic ulcer disease excluding bleeding | 9.242 | 1.018 | 83.932 | 0.0482* |
| Elx. Gr. 20 solid tumor without metastasis | 1.753 | 0.241 | 12.760 | 0.5794 |
| Elx. Gr. 21 rheumatoid arthritis/collagen | 2.238 | 0.676 | 7.415 | 0.1874 |
| Elx. Gr. 23 obesity | 2.303 | 0.850 | 6.235 | 0.1008 |
| Elx. Gr. 24 weight loss | 1.193 | 0.250 | 5.688 | 0.8247 |
| Elx. Gr. 25 fluid and electrolyte disorders | 1.125 | 0.369 | 3.430 | 0.8358 |
| Elx. Gr. 27 deficiency anemia | 0.649 | 0.140 | 3.015 | 0.5815 |
| Elx. Gr. 28 alcohol abuse | 3.394 | 0.845 | 13.637 | 0.0851 |
| Elx. Gr. 29 drug abuse | 2.423 | 0.468 | 12.54 | 0.2913 |
| Elx. Gr. 30 psychoses | 1.927 | 0.192 | 19.367 | 0.5776 |
| Elx. Gr. 31 depression | 1.273 | 0.517 | 3.135 | 0.5994 |
| FCI category 0 (vs 4+) | 0.810 | 0.185 | 3.557 | 0.7803 |
| FCI category 1 (vs 4+) | 0.589 | 0.171 | 2.033 | 0.4026 |
| FCI category 2 (vs 4+) | 0.536 | 0.175 | 1.644 | 0.2757 |
| FCI category 3 (vs 4+) | 0.490 | 0.150 | 1.598 | 0.2372 |
| Charlson Comorbidity Index | 0.705 | 0.363 | 1.370 | 0.3024 |
| New injury severity scores | 1.038 | 0.977 | 1.103 | 0.2236 |
| Osteoporosis (vs not) | 1.000 | 0.448 | 2.235 | 0.9996 |
| Subtrochanteric (vs not) | 2.451 | 1.243 | 4.833 | 0.0097* |
| Pathological fracture (vs not) | 2.922 | 1.143 | 7.468 | 0.0251* |
| Open fracture (vs not) | 0.829 | 0.101 | 6.780 | 0.8613 |
Note: *Statistical significance at the p<0.05 level.
Abbreviations: Elx., Elixhauser Comorbidity Index; FCI, Functional Comorbidity Index; Gr, grade; HMO, health maintenance organization; IMN, intramedullary nail; PPO, preferred provider organization.