Table 1.
Baseline characteristics by smoking exposure
| Smoking Status by Urine NNAL | ||||
|---|---|---|---|---|
| Characteristic | Nonsmoker 0 pg/ml (N=143) | Passive smoker >0, <47.3 pg/ml (N=101) | Active smoker >=47.3 pg/ml (N=137) | P-value |
| Age (years), mean ± SD | 59 ± 18 | 47 ± 16a | 48 ± 13b | <0.001 |
| Male gender, n (%) | 70 (49) | 59 (58) | 84 (61) | 0.1 |
| Race, n (%) | 0.004 | |||
| White | 112 (78) | 65 (64) | 113 (82) | |
| African American | 17 (12) | 27 (27) | 19 (14) | |
| Asian | 6 (4) | 2 (2) | 0 (0) | |
| Other | 8 (6) | 7 (7) | 5 (4) | |
| Hispanic Ethnicity, n (%) | 12 (8) | 14 (14) | 14 (10) | 0.39 |
| Primary etiology of lung injury, n (%) | 0.18 | |||
| Trauma | 6 (4) | 9 (9) | 11 (8) | |
| Sepsis | 44 (31) | 24 (24) | 23 (17) | |
| Multiple transfusion | 3 (2) | 4 (4) | 1 (1) | |
| Aspiration | 21 (15) | 16 (16) | 30 (22) | |
| Pneumonia | 62 (43) | 42 (42) | 63 (46) | |
| Other | 7 (5) | 6 (6) | 9 (7) | |
| Alcohol use, n (%)c | <0.001 | |||
| Abstinence | 89 (62) | 46 (46) | 38 (28) | |
| Low-risk | 36 (25) | 27 (27) | 28 (20) | |
| Mild to moderate alcohol misuse | 2 (1) | 7 (7) | 12 (9) | |
| Severe alcohol misuse | 2 (1) | 11 (11) | 31 (23) | |
| Unknown history | 14 (10) | 10 (10) | 28 (20) | |
| Smoking history | <0.001 | |||
| Non-smoker | 94 (65) | 45 (45) | 13 (9) | |
| Former Smoker | 35 (24) | 24 (24) | 16 (12) | |
| Active Smoker | 1 (1) | 23 (23) | 90 (66) | |
| Unknown history | 14 (10) | 9 (9) | 18 (13) | |
| Pack-years, median [IQR] | 0 [0, 5] | 0 [0, 17] | 30 [9, 45]* | 0.0001 |
| Time in hospital prior to urine collection (days), median [IQR) | 1 [0, 3] | 2 [0, 4] | 1 [0, 3] | 0.10 |
| Comorbidities, n (%) | ||||
| Immune suppression | 20 (14) | 8 (8) | 3 (2)* | 0.001 |
| Diabetes | 49 (34) | 28 (28) | 26 (19)* | 0.02 |
| Prior myocardial infarction | 15 (10) | 5 (5) | 4 (3)* | 0.03 |
| Hypertension | 79 (55) | 43 (43)† | 33 (24)* | <0.001 |
| Congestive heart failure | 11 (8) | 8 (8) | 2 (1)* | 0.02 |
| Chronic pulmonary disease | 13 (9) | 2 (2)† | 14 (10) | 0.03 |
| Prior stroke with sequelae | 10 (7) | 3 (3) | 0 (0)* | 0.002 |
| Dementia | 9 (6) | 2 (2) | 2 (1) | 0.09 |
| AIDS | 2 (1) | 3 (3) | 2 (2) | 0.62 |
| Hepatic failure | 0 (0) | 2 (2) | 0 (0) | 0.07 |
| Malignancy | 3 (2) | 1 (1) | 0 (0) | 0.23 |
| APACHE III score, mean ± SD | 97 ± 29 | 91 ± 28 | 85 ± 26* | 0.001 |
| Vasopressor use at baseline, n (%) | 84 (59) | 50 (50) | 56 (41)* | 0.01 |
| Septic shock at enrollment, n (%) | 72 (50) | 36 (36)† | 42 (31)* | 0.002 |
a
Passive vs nonsmoker p≤0.05;
b
Active smoker vs nonsmoker p≤0.05
c
As defined by Alcohol Use Disorders Identification Test (AUDIT) scores (Online Supplement, Table S1)
Definition of abbreviations: APACHE III = Acute Physiology and Chronic Health Evaluation III