Table 1.
Baseline Characteristics of the Study Population
| Characteristics | The Level of NPAR | P value | ||
|---|---|---|---|---|
| <22.56 (n=980) | 22.56–27.64 (n=980) | >27.64 (n=982) | ||
| NPAR, dl/g | 18.55 ± 4.19 | 25.03 ± 1.40 | 33.82 ± 6.40 | <0.001 |
| Clinical parameters | ||||
| Age, years | 72.13 ± 13.95 | 72.99 ± 13.52 | 73.11 ± 14.13 | 0.237 |
| Gender, n(%) | 0.420 | |||
| Male | 520 (53.06) | 497 (50.71) | 494 (50.31) | |
| Female | 460 (46.94) | 483 (49.29) | 488 (49.69) | |
| Ethnicity, n(%) | <0.001 | |||
| White | 687 (70.10) | 712 (72.65) | 724 (73.73) | |
| Black | 153 (15.61) | 107 (10.92) | 88 (8.96) | |
| Other | 140 (14.29) | 161 (16.43) | 170 (17.31) | |
| Vital signs | ||||
| SBP, mmHg | 118.54 ± 18.36 | 117.26 ± 17.13 | 113.45 ± 16.82 | <0.001 |
| DBP, mmHg | 60.11 ± 11.80 | 58.02 ± 10.17 | 55.95 ± 10.38 | <0.001 |
| MAP, mmHg | 77.31 ± 11.89 | 75.65 ± 10.49 | 73.38 ± 11.01 | <0.001 |
| Heart rate, beats/minute | 83.32 ± 16.61 | 84.45 ± 16.19 | 87.92 ± 16.11 | <0.001 |
| RR, times/minute | 19.79 ± 3.92 | 20.16 ± 4.07 | 20.34 ± 4.16 | 0.009 |
| Temperature, °C | 36.75 ± 0.65 | 36.78 ± 0.67 | 36.74 ± 0.70 | 0.461 |
| SpO2, % | 96.89 ± 2.07 | 96.77 ± 2.63 | 96.99 ± 2.83 | 0.170 |
| Comorbidities, n(%) | ||||
| CHF | 942 (96.12) | 944 (96.33) | 956 (97.35) | 0.273 |
| Cardiac arrhythmias | 526 (53.67) | 571 (58.27) | 559 (56.92) | 0.109 |
| Infected | 412 (42.04) | 547 (55.82) | 691 (70.37) | <0.001 |
| Valvular disease | 245 (25.00) | 246 (25.10) | 195 (19.86) | 0.007 |
| Pulmonary circulation | 134 (13.67) | 137 (13.98) | 109 (11.10) | 0.113 |
| Chronic pulmonary | 324 (33.06) | 354 (36.12) | 306 (31.16) | 0.063 |
| Hypertension | 636 (64.90) | 634 (64.69) | 528 (53.77) | <0.001 |
| Renal failure | 330 (33.67) | 341 (34.80) | 325 (33.10) | 0.721 |
| Laboratory parameters | ||||
| Albumin, g/dl | 3.73 ± 0.48 | 3.31 ± 0.34 | 2.62 ± 0.41 | <0.001 |
| Serum creatinine, mg/dl | 2.14 ± 2.11 | 2.10 ± 1.91 | 2.10 ± 1.75 | 0.838 |
| Glucose, mg/dl | 160.28 ± 93.25 | 168.67 ± 96.08 | 155.49 ± 98.02 | 0.009 |
| Serum urea nitrogen, mg/dl | 38.63 ± 27.12 | 40.65 ± 27.80 | 44.10 ± 29.20 | <0.001 |
| Hematocrit, % | 35.18 ± 6.73 | 33.29 ± 6.57 | 31.49 ± 5.71 | <0.001 |
| Hemoglobin, g/dl | 11.66 ± 2.28 | 10.98 ± 2.23 | 10.30 ± 1.94 | <0.001 |
| WBC, 109/l | 11.90 ± 13.77 | 13.10 ± 7.37 | 15.25 ± 8.63 | <0.001 |
| Neutrophil percentage, % | 69.53 ± 17.54 | 82.78 ± 8.00 | 86.53 ± 6.97 | <0.001 |
| Platelet, 109/l | 234.15 ± 119.42 | 251.99 ± 118.31 | 266.00 ± 140.54 | <0.001 |
| RDW, fl | 15.50 ± 2.18 | 15.65 ± 2.18 | 16.26 ± 2.30 | <0.001 |
| Sodium, mmol/l | 137.87 ± 5.28 | 138.04 ± 5.44 | 138.36 ± 5.90 | 0.135 |
| Potassium, mmol/l | 4.42 ± 0.88 | 4.38 ± 0.78 | 4.29 ± 0.78 | 0.002 |
| Bicarbonate, mmol/l | 24.68 ± 5.83 | 24.20 ± 5.89 | 23.60 ± 5.90 | <0.001 |
| Anion gap, mmol/l | 16.92 ± 4.63 | 16.52 ± 4.50 | 15.78 ± 4.45 | <0.001 |
| APTT, second | 38.58 ± 25.17 | 38.91 ± 24.87 | 40.37 ± 25.11 | 0.256 |
| INR | 1.76 ± 1.46 | 1.92 ± 1.94 | 1.87 ± 1.74 | 0.126 |
| PT, second | 17.52 ± 9.58 | 18.74 ± 13.45 | 19.03 ± 15.55 | 0.029 |
| Scoring systems | ||||
| SAPSII | 40.07 ± 12.80 | 40.88 ± 11.57 | 45.41 ± 14.03 | <0.001 |
| APSIII | 49.55 ± 18.08 | 50.97 ± 16.63 | 59.91 ± 20.80 | <0.001 |
| In-hospital management, n(%) | ||||
| Vasopressin use | 336 (34.29) | 368 (37.55) | 470 (47.86) | <0.001 |
| RRT | 71 (7.24) | 69 (7.04) | 89 (9.06) | 0.184 |
| Mechanical ventilation | 382 (38.98) | 424 (43.27) | 486 (49.49) | <0.001 |
| Primary outcome, n(%) | ||||
| 30-day mortality | 137 (13.98) | 170 (17.35) | 291 (29.63) | <0.001 |
| Secondary outcomes | ||||
| In-hospital mortality, n(%) | 115 (11.73) | 126 (12.86) | 228 (23.22) | <0.001 |
| 90-day mortality, n(%) | 212 (21.63) | 263 (26.84) | 404 (41.14) | <0.001 |
| 365-day mortality, n(%) | 347 (35.41) | 408 (41.63) | 566 (57.64) | <0.001 |
| Hospital LOS, day | 10.79 ± 10.92 | 11.53 ± 9.30 | 14.66 ± 12.68 | <0.001 |
Note: The data came from patients in MIMIC III database.
Abbreviations: NPAR, ratio of neutrophil to albumin; SBP, systolic blood pressure; DBP, diastolic blood pressure; MAP, mean arterial pressure; RR, respiratory rate; SpO2, pulse oximetry-derived oxygen saturation; CHF, congestive heart failure; WBC, white blood cell count; RDW, red blood cell distribution width; APTT, activated partial thromboplastin time; INR, international normalized ratio; PT, prothrombin time; SAPSII, simple acute physiology score II; APSIII, acute physiology score III; RRT, renal replacement treatment; LOS, length of stay.