Table 3.
Lung Cancer Model Univariate and Multivariate Analysis
| Parameter | Univariate Cox Model |
Multivariate Cox Modela |
|||||
|---|---|---|---|---|---|---|---|
| HR | 95% CI | P Value | HR | 95% CI | P Value | ||
| Age | 0.99 | 0.98 | 1.01 | .643 | ... | ... | ... |
| Male sex | 1.05 | 0.71 | 1.57 | .797 | ... | ... | ... |
| ECOG | |||||||
| 0 | 1 | ... | ... | ... | ... | ... | ... |
| 1 | 1.48 | 0.42 | 5.18 | .543 | 1.67 | 0.45-6.14 | .44 |
| 2 | 4.27 | 1.31 | 13.91 | .016 | 3.76 | 1.11-12.66 | .03 |
| 3 | 5.27 | 1.62 | 17.23 | .006 | 3.44 | 0.96-12.24 | .06 |
| 4 | 6.89 | 1.86 | 25.56 | .004 | 4.45 | 1.09-18.11 | .04 |
| CHF present | 1.44 | 0.67 | 3.12 | .349 | ... | ... | ... |
| Ascites present | 2.79 | 0.88 | 8.83 | .082 | ... | ... | ... |
| High clinical suspicion of pneumonia | 1.10 | 0.68 | 1.79 | .689 | ... | ... | ... |
| Chemotherapy within 30 d prior | 0.99 | 0.66 | 1.49 | .983 | ... | ... | ... |
| Radiation within 30 d before tap | 1.09 | 0.63 | 1.89 | .760 | ... | ... | ... |
| Surgery within 30 d before tap | 2.48 | 1.01 | 6.11 | .049 | 2.24 | 0.77-6.53 | .14a |
| Right-sided effusion present | 0.99 | 0.66 | 1.49 | .974 | ... | ... | ... |
| Bilateral effusion present | 2.27 | 1.52 | 3.40 | < .001 | 2.25 | 1.44-3.53 | < .001 |
| Size of the effusion on chest radiograph | |||||||
| Up to apex diaphragm | 1 | ... | ... | ... | ... | ... | ... |
| Up to vascular pedicle | 1.28 | 0.59 | 2.76 | .53 | ... | ... | ... |
| Up to top of cardiac silhouette | 1.53 | 0.69 | 3.38 | .29 | ... | ... | ... |
| Up to top of aortic arch | 1.16 | 0.42 | 3.20 | .78 | ... | ... | ... |
| Higher than aortic arch | 1.48 | 0.57 | 3.82 | .42 | ... | ... | ... |
| Lung or pleural nodularity thickening or mass on study within 30 d before first tap | 1.28 | 0.72 | 2.30 | .403 | ... | ... | ... |
| Malignant pleural fluid on cytologic analysis | 1.61 | 1.04 | 2.51 | .034 | 1.86 | 1.14-3.05 | .01 |
| Tumor type | |||||||
| Adenocarcinoma | 1 | ... | ... | ... | ... | ... | ... |
| Squamous cell carcinoma | 0.79 | 0.41 | 1.55 | .493 | ... | ... | ... |
| Small cell carcinoma | 1.09 | 0.47 | 2.52 | .845 | ... | ... | ... |
| Unspecified non-small cell | 1.44 | 0.86 | 2.41 | .166 | ... | ... | ... |
| Neutrophil to lymphocyte ratio | 1.03 | 1.02 | 1.05 | < .001 | ... | ... | ... |
| Amount of fluid drained | 1.00 | 1.00 | 1.00 | .442 | ... | ... | ... |
| Pleural fluid LDH/100 | 1.01 | 1.00 | 1.02 | .031 | 1.02 | 1.004-1.03 | .01 |
| Pleural fluid protein | .51 | 0.40 | 0.65 | < .001 | 0.57 | 0.43-0.76 | < .001 |
| Pleural fluid cholesterol | 0.99 | 0.98 | 1.00 | .039 | ... | ... | ... |
| Pleural fluid triglycerides, mg/dL | |||||||
| < 26 | 1 | ... | ... | ... | ... | ... | ... |
| 27-105 | 1.08 | 0.72 | 1.64 | .71 | ... | ... | ... |
| > 105 | 1.11 | 0.27 | 4.55 | .89 | ... | ... | ... |
CHF = congestive heart failure; ECOG = Eastern Cooperative Oncology Group; HR = hazard ratio; LDH/100 = pleural fluid lactate dehydrogenase/100.
a
Using backward regression (n = 167), surgery within 30 d: HR, 4.67; 95% CI, 1.21-18.06; P = .03. Thus, surgery qualifies to be in the model. After identification of the risk factors, the model is reapplied with just the risk factors identified. Because variables like neutrophil to lymphocyte ratio are no longer used, more patients have complete data and sample size increases (n = 172), changing the HR slightly.