Table 3.
Univariate and multivariate Cox proportional hazards regression analysis of survival in IIM-ILD patients.
| Before propensity score matching | After propensity score matching | |||||
|---|---|---|---|---|---|---|
| Factors | P-value | HR value | 95% Cl | P-value | HR value | 95% Cl |
| Age (y) | 0.111 | 1.023 | 0.995~1.052 | 0.059 | 1.031 | 0.999~1.064 |
| Sex (male/female) | 0.872 | 0.950 | 0.505~1.785 | 0.819 | 0.921 | 0.455~1.863 |
| Clinical manifestations or comorbidities | ||||||
| Dysphagia | 0.091 | 1.846 | 0.907~3.756 | 0.054 | 2.278 | 0.987~5.257 |
| Dysarthria | 0.613 | 1.305 | 0.465~3.666 | 0.504 | 0.507 | 0.069~3.714 |
| Respiratory muscle involvement | 0.240 | 2.022 | 0.624~6.554 | 0.610 | 1.679 | 0.229~12.294 |
| Cardiac involvement | 0.166 | 2.076 | 0.739~5.830 | 0.077 | 2.576 | 0.903~7.346 |
| Gastrointestinal hemorrhage | 0.165 | 1.940 | 0.760~4.950 | 0.395 | 1.575 | 0.553~4.489 |
| Pulmonary bacterial infection | 0.005 | 2.435 | 1.311~4.525 | 0.025 | 2.225 | 1.107~4.473 |
| Pulmonary fungal infection | 0.674 | 1.357 | 0.328~5.626 | 0.190 | 2.601 | 0.622~10.878 |
| Carcinoma | 0.868 | 1.071 | 0.476~2.412 | 0.837 | 0.905 | 0.350~2.338 |
| UIP pattern | 0.239 | 1.629 | 0.723~3.671 | 0.417 | 1.441 | 0.596~3.483 |
| Pneumomediastinum | 0.868 | 1.128 | 0.272~4.675 | 0.385 | 0.046 | 0.000~47.796 |
| RP-ILD | <0.001 | 3.930 | 2.108~7.327 | <0.001 | 3.927 | 1.964~7.851 |
| Disease activity | ||||||
| MYOACT score | <0.001 | 1.261 | 1.156~1.375 | <0.001 | 1.226 | 1.114~1.348 |
| Lung function testing | ||||||
| FVC% (%) | 0.228 | 0.990 | 0.973~1.006 | 0.561 | 0.995 | 0.976~1.013 |
| TLC (L) | 0.103 | 0.773 | 0.568~1.054 | 0.346 | 0.850 | 0.606~1.192 |
| FEV1% (%) | 0.134 | 0.988 | 0.972~1.004 | 0.327 | 0.991 | 0.973~1.009 |
| FEV1/FVC | 0.814 | 1.415 | 0.079~25.465 | 0.882 | 0.740 | 0.014~39.720 |
| DLCO% (%) | 0.006 | 0.977 | 0.960~0.993 | 0.042 | 0.979 | 0.960~0.999 |
| Myositis-specific antibodies and myositis-associated antibodies | ||||||
| Anti-MDA5 | <0.001 | 4.318 | 2.324~8.023 | <0.001 | 4.734 | 2.372~9.451 |
| Anti-PL-7 | 0.481 | 0.690 | 0.246~1.935 | 0.518 | 0.676 | 0.206~2.217 |
| Anti-PL-12 | 0.696 | 0,673 | 0.093~4.902 | 0.917 | 0.899 | 0.123~6.586 |
| Anti-EJ | 0.718 | 1.242 | 0.383~4.026 | 0.985 | 1.014 | 0.242~4.240 |
| Anti-Ro-52 | 0.374 | 1.320 | 0.716~2.436 | 0.326 | 1.415 | 0.707~2.831 |
| Anti-Jo-1 | 0.455 | 0.719 | 0.303~1.709 | 0.575 | 0.777 | 0.321~1.879 |
| Anti-OJ | 0.862 | 1.192 | 0.163~8.696 | 0.890 | 1.152 | 0.157~8.453 |
| Anti-TIF1γ | 0.813 | 0.883 | 0.315~2.479 | 0.644 | 0.756 | 0.230~2.479 |
| Anti-Ku | 0.977 | 1.021 | 0.246~4.229 | 0.547 | 1.553 | 0.371~6.494 |
| Anti-SRP | 0.357 | 0.046 | 0.000~31.881 | 0.406 | 0.046 | 0.000~64.547 |
| Anti-NXP2 | 0.167 | 0.247 | 0.034~1.794 | 0.342 | 0.381 | 0.052~2.791 |
| Anti-PM-Scl75 | 0.817 | 1.130 | 0.402~3.175 | 0.331 | 1.681 | 0.590~4.791 |
| Anti-PM-Scl100 | 0.838 | 1.234 | 0.166~9.179 | 0.257 | 3.175 | 0.431~23.391 |
| Anti-Mi-2α | 0.748 | 0.792 | 0.191~3.281 | 0.404 | 0.046 | 0.000~62.827 |
| Anti-Mi-2β | 0.942 | 0.949 | 0.229~3.933 | 0.467 | 0.047 | 0.000~178.915 |
| Anti-SAE1 | 0.551 | 0.546 | 0.075~3.988 | 0.637 | 0.619 | 0.084~4.556 |
| Comorbidities/harmful hobbies | ||||||
| Smoking | 0.717 | 0.841 | 0.330~2.145 | 0.716 | 0.824 | 0.289~2.344 |
| Alcohol abuse | 0.867 | 1.065 | 0.508~2.232 | 0.778 | 1.127 | 0.489~2.598 |
| Hypertension | 0.576 | 0.781 | 0.329~1.855 | 0.791 | 0.888 | 0.368~2.144 |
| Diabetes | 0.540 | 0.763 | 0.321~1.812 | 0.457 | 0.697 | 0.269~1.804 |
| Hepatitis | 0.816 | 1.096 | 0.507~2.370 | 0.830 | 0.908 | 0.375~2.197 |
| Allergic history | 0.053 | 0.246 | 0.059~1.017 | 0.143 | 0.040 | 0.001~2.968 |
| Therapies | ||||||
| Steroid monotherapy | 0.065 | 1.001 | 1.000~1.003 | 0.141 | 1.001 | 1.000~1.002 |
| Steroid + DMARDs | 0.623 | 0.859 | 0.469~1.574 | 0.163 | 0.618 | 0.314~1.216 |
| Steroid + IVIG | 0.390 | 1.429 | 0.633~3.225 | 0.088 | 2.070 | 0.898~4.775 |
| Steroid + DMARDs + IVIG | 0.288 | 1.600 | 0.672~3.808 | 0.166 | 1.962 | 0.755~5.094 |
| Maximum dosage of steroid | 0.059 | 1.002 | 1.000~1.003 | 0.134 | 1.001 | 1.000~1.003 |
| Nintedanib | 0.023 | 0.301 | 0.107~0.845 | 0.023 | 0.299 | 0.105~0.849 |
| IIM subtypes | ||||||
| DM | 0.744 | 0.901 | 0.483~1.681 | 0.503 | 0.792 | 0.400~1.568 |
| PM | 0.638 | 0.838 | 0.401~1.752 | 0.662 | 0.830 | 0.361~1.910 |
| ADM | 0.257 | 1.602 | 0.709~3.617 | 0.122 | 1.934 | 0.838~4.465 |
| Multivariate analysis | ||||||
| MYOACT score | <0.001 | 1.214 | 1.110~1.328 | 0.001 | 1.174 | 1.068~1.291 |
| Anti-MDA5 | <0.001 | 3.300 | 1.714~6.357 | <0.001 | 4.170 | 2.011~8.649 |
| Nintedanib | 0.013 | 0.268 | 0.096~0.754 | 0.013 | 0.264 | 0.093~0.753 |
IIM-ILD, Idiopathic-inflammatory-myopathy-related interstitial lung disease; y, years; m, months; UIP pattern, Usual interstitial pneumonia pattern; RP-ILD, Rapidly progressive interstitial lung disease; MYOACT, Myositis Disease Activity Assessment Visual Analog Scales; FVC%, Percent-predicted forced vital capacity; TLC, Total lung capacity; L, Liter; FEV1%, Percent-predicted forced expiratory volume in 1 s; FEV1/FVC, Ratio of FEV1 over FVC; DLCO%, Percent-predicted diffusing capacity of the lung for carbon monoxide; DMARDs, Disease-modifying anti-rheumatic drugs; IVIG, Intravenous immunoglobulin; IIM, Idiopathic inflammatory myopathy; DM, dermatomyositis; PM, Polymyositis; ADM, Amyopathic dermatomyositis.
aCalculated by prednisolone.