Table 4. Risk factors for acute exacerbation of chronic obstructive pulmonary disease by Cox proportional hazards model.
| Variables | Univariate analysis | Multivariate analysis | ||||
|---|---|---|---|---|---|---|
| HR | 95% CI | P value | HR | 95% CI | P value | |
| Age, yr | 1.020 | 1.000–1.040 | 0.023 | 1.020 | 1.001–1.040 | 0.043 |
| BMI, kg/m2 | 0.950 | 0.910–1.000 | 0.061 | 0.963 | 0.913–1.015 | 0.156 |
| SGRQ | 1.010 | 1.010–1.020 | < 0.001 | 1.010 | 1.001–1.019 | 0.038 |
| Hyperuricemia, UA > 7.0 mg/dL | 1.340 | 0.960–1.870 | 0.087 | 1.383 | 0.977–1.959 | 0.068 |
| CrCl, mL/min | 1.000 | 0.990–1.010 | 0.938 | - | - | - |
| NLR | 1.010 | 0.980–1.050 | 0.440 | - | - | - |
| FEV1, % predicted | 0.990 | 0.980–0.990 | 0.001 | 0.988 | 0.979–0.998 | 0.015 |
| DLCO, % predicted | 1.000 | 0.990–1.000 | 0.385 | - | - | - |
| 6MWD, m | 1.000 | 1.000–1.000 | 0.128 | 1.001 | 0.999–1.003 | 0.397 |
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 ration, FEV1 = forced expiratory volume in 1 second, DLCO = diffusing capacity of the lung for carbon monoxide, 6MWD = 6-minute walk distance.