Table 1.
Baseline cohort characteristics by NLR group
| Characteristic | Low NLR N=8,794 |
High NLR N=2,393 |
p-value |
|---|---|---|---|
| Age, mean (SD) | 63.2 (10.4) | 63.9 (9.5) | 0.003 |
| Men, No. (%) | 8,609 (97.9) | 2,376 (99.3) | <0.001 |
| Race/ethnicity, No. (%) | 0.005 | ||
| White | 6,068 (69.0) | 1,740 (72.7) | |
| Black | 982 (11.2) | 232 (9.7) | |
| Hispanic | 730 (8.3) | 181 (7.6) | |
| Other | 954 (10.9) | 232 (9.7) | |
| Missing | 60 (0.7) | 8 (0.3) | |
| Year of surgery, No. (%) | <0.001 | ||
| 2000–2005 | 3,199 (36.4) | 932 (39.0) | |
| 2006–2010 | 2,829 (32.2) | 747 (31.2) | |
| 2011–2015 | 2,537 (25.3) | 607 (25.4) | |
| 2016–2020 | 229 (2.6) | 107 (4.5) | |
| Current Smoker, No. (%) | 4,659 (53.0) | 1,285 (53.7) | 0.81 |
| Missing | 3 (0.03) | 1 (0.04) | |
| Alcohol Use*, No. (%) | 1,618 (18.4) | 416 (17.4) | 0.11 |
| Missing | 11 (0.13) | 0 (0.00) | |
| Charlson Comorbidity Index†, No. (%) | <0.001 | ||
| 0–1 | 6,298 (71.6) | 1,611 (67.3) | |
| 2–3 | 1,689 (19.2) | 543 (22.7) | |
| 4–5 | 532 (6.1) | 173 (7.2) | |
| 6+ | 275 (3.1) | 66 (2.8) | |
| ASA Classification, No. (%) | <0.001 | ||
| 1–2 | 1,584 (18.0) | 206 (8.6) | |
| 3 | 6,415 (73.0) | 1,816 (75.9) | |
| 4–5 | 782 (8.9) | 370 (15.5) | |
| Missing | 13 (0.2) | 1 (0.04) | |
| Risk Analysis Index, No. (%) | <0.001 | ||
| ≤26 | 6,573 (74.7) | 1,352 (56.5) | |
| 27–34 | 1,300 (14.8) | 444 (18.6) | |
| ≥35 | 921 (10.5) | 597 (25.0) | |
| Surgical Procedure, No. (%) | <0.001 | ||
| Laryngectomy | 1,274 (14.5) | 561 (23.4) | |
| Neck dissection | 2,372 (27.0) | 758 (31.7) | |
| Oral cavity | 2,577 (29.3) | 503 (21.0) | |
| Parotidectomy | 360 (4.1) | 61 (2.6) | |
| Cutaneous excision | 888 (10.1) | 169 (7.1) | |
| Thyroidectomy | 288 (3.3) | 44 (1.8) | |
| Sinus/Skull base | 285 (3.2) | 57 (2.4) | |
| Reconstruction | 496 (5.6) | 178 (7.4) | |
| Oropharyngectomy | 254 (2.9) | 62 (2.6) | |
| Chemotherapy‡, No. (%) | 109 (1.2) | 75 (3.1) | <0.001 |
| Missing | 26 (0.3) | 13 (0.5) | |
| Body Mass Index (BMI), mean (SD) | 26.3 (5.5) | 24.0 (5.3) | <0.001 |
| Missing, No. (%) | 913 (10.4) | 278 (11.6) | |
| Preoperative Hematocrit (%), mean (SD) | 41.1 (5.0) | 38.0 (5.7) | <0.001 |
| Missing, No. (%) | 245 (2.9) | 31 (1.3) | |
| Preoperative Serum Creatinine (mg/dl), mean (SD) | 1.0 (0.4) | 1.0 (0.6) | 0.35 |
| Missing, No. (%) | 283 (3.2) | 56 (2.3) |
Abbreviations: NLR, neutrophil-to-lymphocyte ratio; ASA, American Society of Anesthesiologists
*
>2 drinks/day in 2 weeks before admission
†
Diagnosed within 1 year prior to surgery
‡
Chemotherapy for malignancy within 30 days prior to surgery