Table 2.
Bivariate descriptive statistics in the lung adenocarcinoma study (N = 390).
| Covariate | Never smokers N = 61 | Current smokers N = 91 | Former ≤ 15 years N = 135 | Former > 15 years N = 103 | P-value |
|---|---|---|---|---|---|
| Sex N(%) | 0.0027 | ||||
| Male | 17 (27.9) | 52 (57.1) | 56 (41.5) | 51 (49.5) | |
| Age Mean(IQR) | 65.6 (14) | 61.4 (13) | 63.9 (12) | 70.5 (10) | 3.27 × 10−10 |
| Smoking pack years Mean(IQR) | — | 52.1 (28.0) | 42.8 (26.5) | 32.5 (24.25) | 4.02 × 10−5 |
| Missing (%) | — | 16 (17.6) | 17 (12.6) | 19 (18.4) | |
| Race N(%) | 0.66 | ||||
| White | 52 (85.2) | 73 (80.2) | 108 (80.0) | 88 (85.4) | |
| Black | 3 (4.9) | 11 (12.1) | 13 (9.6) | 8 (7.8) | |
| Asian | 2 (3.3) | 2 (2.2) | 2 (1.5) | 0 (0.0) | |
| Unknown | 4 (6.6) | 5 (5.5) | 12 (8.9) | 7 (6.8) | |
| Cancer stage N(%) | 0.58 | ||||
| I | 30 (49.2) | 49 (53.8) | 75 (55.6) | 62 (60.2) | |
| II | 17 (27.9) | 27 (29.7) | 27 (20.0) | 22 (21.4) | |
| III | 9 (14.8) | 11 (12.1) | 26 (19.3) | 16 (15.5) | |
| IV | 5 (8.2) | 4 (4.4) | 7 (5.2) | 3 (2.9) |
We report mean (IQR) for continuous covariates and frequency (percent) for categorical covariates and test for differences among the smoking categories, using Fisher’s test for categorical variables and ANOVA for continuous variables.