Table 1.
Final Cohort Characteristics and Univariate Analysis
| Covariate | Entire Group (N = 562) | Alive (n = 224) | Dead (n = 296) | Lost to Follow-up (n = 42) | Univariate Analysis |
||
|---|---|---|---|---|---|---|---|
| Hazard Ratio | 95% CI | P Value | |||||
| Sex | 1.03 | 0.82-1.30 | .802 | ||||
| Female | 325 (57.83) | 128 (57.14) | 172 (58.11) | 25 (59.52) | |||
| Male | 237 (42.17) | 96 (42.86) | 124 (41.89) | 17 (40.48) | |||
| Age, y | 1.00 | 0.99-1.01 | .461 | ||||
| Median (IQR) | 62 (53-70) | 61 (51.5-69) | 63 (54-70) | 63.5 (52-72) | |||
| Mean (SD) | 60.7 (13.73) | 59.8 (13.6) | 61.1 (13.7) | 62.3 (14.6) | |||
| ECOG performance status | < .001 | ||||||
| 0 | 31 (5.92) | 20 (9.62) | 5 (1.81) | 6 (15.38) | Reference | ... | ... |
| 1 | 113 (21.56) | 65 (31.25) | 41 (14.8) | 7 (17.95) | 2.52 | 0.99-6.38 | .051 |
| 2 | 183 (34.92) | 55 (26.44) | 113 (40.79) | 15 (38.46) | 5.52 | 2.25-13.53 | < .001 |
| 3 | 152 (29.01) | 57 (27.4) | 86 (31.05) | 9 (23.08) | 5.86 | 2.38-14.44 | < .001 |
| 4 | 45 (8.59) | 11 (5.29) | 32 (11.55) | 2 (5.13) | 8.83 | 3.44-22.69 | < .001 |
| Cancer type | .674 | ||||||
| Lung | 182 (32.38) | 71 (31.7) | 96 (32.43) | 15 (35.71) | Reference | ... | ... |
| Breast | 138 (24.56) | 59 (26.34) | 71 (23.99) | 8 (19.05) | 0.97 | 0.71-1.31 | .821 |
| Hematologic | 242 (43.06) | 94 (41.96) | 129 (43.58) | 19 (45.24) | 0.94 | 0.73-1.23 | .672 |
| CHF present | |||||||
| No | 511 (90.93) | 208 (92.86) | 266 (89.86) | 37 (88.10) | Reference | ... | ... |
| Yes | 51 (9.07) | 16 (7.14) | 30 (10.14) | 5 (11.90) | 1.33 | 0.91-1.94 | .142 |
| Ascites present | |||||||
| No | 521 (92.7) | 217 (96.88) | 266 (89.86) | 38 (90.48) | Reference | ... | ... |
| Yes | 41 (7.3) | 7 (3.13) | 30 (10.14) | 4 (9.52) | 1.91 | 1.31-2.79 | .001 |
| High clinical suspicion of pneumonia | |||||||
| No | 348 (61.92) | 154 (68.75) | 168 (56.76) | 26 (61.9) | Reference | ... | ... |
| Yes | 214 (38.08) | 70 (31.25) | 128 (43.24) | 16 (38.1) | 1.36 | 1.08-1.71 | .009 |
| Chemotherapy within 30 d before tap | |||||||
| No | 260 (46.26) | 110 (49.11) | 129 (43.58) | 21 (50) | Reference | ... | ... |
| Yes | 302 (53.74) | 114 (50.89) | 167 (56.42) | 21 (50) | 1.08 | 0.86-1.36 | .504 |
| Radiation within 30 d before tap | |||||||
| No | 506 (90.04) | 208 (92.86) | 261 (88.18) | 37 (88.10) | Reference | ... | ... |
| Yes | 56 (9.96) | 16 (7.14) | 35 (11.82) | 5 (11.90) | 1.45 | 1.02-2.06 | .040 |
| Surgery within 30 d before first thoracentesis | |||||||
| No | 553 (98.4) | 223 (99.55) | 288 (97.30) | 42 | Reference | ... | ... |
| Yes | 9 (1.6) | 1 (0.45) | 8 (2.70) | 0 | 2.40 | 1.19-4.86 | .014 |
| Side of pleural effusion of interest | |||||||
| Right | 308 (54.8) | 122 (54.46) | 166 (56.08) | 20 (47.62) | Reference | ... | ... |
| Left | 254 (45.2) | 102 (45.54) | 130 (43.92) | 22 (52.38) | 0.95 | 0.76-1.20 | .679 |
| Bilateral effusion present | |||||||
| No | 259 (46.09) | 108 (48.21) | 133 (44.93) | 18 (42.86) | Reference | ... | ... |
| Yes | 303 (53.91) | 116 (51.79) | 163 (55.07) | 24 (57.14) | 1.12 | 0.89-1.40 | .350 |
| Size of effusion on most recent chest radiographs within 2 w before first thoracentesis | .302 | ||||||
| Up to apex diaphragm | 63 (12.23) | 28 (13.21) | 26 (9.77) | 9 (24.32) | Reference | ... | ... |
| Up to vascular pedicle | 228 (44.27) | 87 (41.04) | 120 (45.11) | 21 (56.76) | 1.14 | 0.75-1.72 | .542 |
| Up to top of cardiac silhouette | 155 (30.1) | 68 (32.08) | 84 (31.58) | 3 (8.11) | 1.23 | 0.80-1.88 | .350 |
| Up to top of aortic arch | 36 (6.99) | 14 (6.6) | 19 (7.14) | 3 (8.11) | 1.26 | 0.70-2.26 | .434 |
| Higher than aortic arch | 33 (6.41) | 15 (7.08) | 17 (6.39) | 1 (2.70) | 1.24 | 0.68-2.27 | .477 |
| Lung or pleural nodularity thickening or mass > 1 cm during study within 30 d before first tap? | |||||||
| No | 260 (46.26) | 111 (49.55) | 132 (44.59) | 17 (40.48) | Reference | ... | ... |
| Yes | 302 (53.74) | 113 (50.45) | 164 (55.41) | 25 (59.52) | 1.14 | 0.91-1.43 | .267 |
| Malignant pleural fluid cytologic examination | |||||||
| No | 251 (44.74) | 110 (49.33) | 114 (38.51) | 27 (44.74) | Reference | ... | ... |
| Yes | 310 (55.26) | 113 (50.67) | 182 (61.49) | 15 (35.71) | 1.53 | 1.21-1.94 | < .001 |
| Neutrophil to lymphocyte ratio, K/μL | 6.11 (2.94-12.54) | 5.19 (2.80-9.74) | 7.52 (3.51-15.04) | 4.77 (2.74-9.08) | 1.01 | 1.00-1.01 | .009 |
| Amount of pleural fluid drained, mL | 1,000 (700-1,300) | 1,000 (750-1,300) | 1,000 (725-1,300) | 775 (550-1,250) | 1.00 | 1.00-1.00 | .454 |
| Pleural fluid LDH/100, U/L | 5.89 (3.27-11.92) | 4.65 (3.05-9.36) | 7.51 (3.95-14.83) | 3.91 (2.74-9.02) | 1.00 | 1.00-1.00 | .136 |
| Pleural fluid protein, g/dL | 3.4 (2.6-4.1) | 3.8 (2.9-4.4) | 3.2 (2.4-3.8) | 3.4 (2.7-4) | 0.69 | 0.61-0.78 | < .001 |
| Pleural fluid cholesterol, mg/dL | 59 (50-78.5) | 65 (50-84) | 53 (50-73) | 52.5 (50-76) | 0.99 | 0.98-0.99 | < .001 |
| Pleural fluid triglycerides, mg/dL | 26 (26-39) | 26 (26-39) | 27.5 (26-38) | 26 (26-31) | 1.00 | 1.00-1.00 | .042 |
Data are presented as No. (%) or median (interquartile range), unless otherwise indicated. CHF = congestive heart failure; ECOG = Eastern Cooperative Oncology Group; HR = hazard ratio; IQR = interquartile range; LDH/100 = pleural fluid lactate dehydrogenase/100.