Table 3. Risk factors for mortality by Cox proportional hazards model.
| Variables | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P value | HR | 95% CI | P value | |
| Age, yr | 1.120 | 1.070–1.180 | < 0.001 | 1.098 | 1.035–1.164 | 0.002 |
| BMI, kg/m2 | 0.750 | 0.680–0.820 | < 0.001 | 0.796 | 0.701–0.903 | < 0.001 |
| SGRQ | 1.030 | 1.010–1.040 | < 0.001 | 0.983 | 0.960–1.007 | 0.156 |
| Hyperuricemia, UA > 7.0 mg/dL | 0.580 | 0.250–1.370 | 0.213 | - | - | - |
| CrCl, mL/min | 0.940 | 0.920–0.970 | < 0.001 | 0.989 | 0.959–1.020 | 0.494 |
| NLR | 1.050 | 1.000–1.090 | 0.031 | 1.024 | 0.970–1.082 | 0.389 |
| FEV1, % predicted | 0.960 | 0.940–0.980 | < 0.001 | 0.986 | 0.960–1.012 | 0.288 |
| DLCO, % predicted | 0.970 | 0.960–0.980 | < 0.001 | 0.980 | 0.965–0.995 | 0.010 |
| 6MWD, m | 0.990 | 0.990–0.990 | < 0.001 | 0.996 | 0.992–1.001 | 0.092 |
Cox proportional hazard analysis was used to identify independent risk factors for mortality.
HR = hazard ratio, CI = confidence interval, BMI = body mass index, SGRQ = St. George's Respiratory Questionnaire, UA = uric acid, CrCl = creatinine clearance estimate by the Cockcroft-Gault Equation, NLR = neutrophil–lymphocyte ratio, FEV1 = forced expiratory volume in 1 second, DLCO = diffusing capacity of the lung for carbon monoxide, 6MWD = 6-minute walk distance.