Table 2.
General Cancer Cox Model Using Interaction Terms
| Interaction Term | HR | 95% CI | P Value |
|---|---|---|---|
| ECOG performance status | |||
| 0 | Reference | ... | ... |
| 1 | 2.35 | 0.92-6.01 | .075 |
| 2 | 4.42 | 1.78-10.95 | .001 |
| 3 | 4.27 | 1.70-10.71 | .002 |
| 4 | 5.78 | 2.19-15.23 | < .001 |
| Malignant pleural fluid cytologic findings | 1.91 | 1.44-2.55 | < .001 |
| Interaction between cancer type and NLR | |||
| Lung cancer × NLR | 1.01 | 0.99-1.03 | .284 |
| Hematologic malignancy × NLR | 1.00 | 0.99-1.01 | .616 |
| Breast cancer × NLR | 1.05 | 1.02-1.08 | .001 |
| Interaction between cancer type and bilateral effusion | |||
| Lung cancer and unilateral effusion | 1.00 (Reference) | ... | ... |
| Lung cancer and bilateral effusion | 2.28 | 1.48-3.53 | < .001 |
| Hematologic malignancies and unilateral effusion | 1.55 | 0.41-5.91 | .522 |
| Hematologic malignancies and bilateral effusion | 0.87 | 0.25-2.98 | .819 |
| Breast cancer and unilateral effusion | 1.04 | 0.19-5.64 | .964 |
| Breast cancer and bilateral effusion | 0.66 | 0.14-3.15 | .603 |
| Interaction between cancer type and pleural fluid LDH/100 | |||
| Lung cancer × LDH/100 | 1.02 | 1.00-1.03 | .016 |
| Hematologic malignancies × LDH/100 | 1.00 | 0.99-1.00 | .826 |
| Breast cancer × LDH/100 | 1.01 | 1.00-1.02 | .078 |
| Interaction between cancer type and pleural fluid protein | |||
| Lung cancer × pleural fluid protein | 0.61 | 0.47-0.79 | < .001 |
| Hematologic malignancies × pleural fluid protein | 0.66 | 0.51-0.84 | .001 |
| Breast cancer × pleural fluid protein | 0.64 | 0.46-0.88 | .007 |
ECOG = Eastern Cooperative Oncology Group; HR = hazard ratio; LDH/100 = pleural fluid lactate dehydrogenase/100; NLR = blood neutrophil to lymphocyte ratio.