Table 4.
Weighted Linear Regression Model for NNAL (ng/mL) (Natural Log-Transformed, N = 11 004) With Tobacco User Group and Demographic Predictors and Pairwise Comparisons for Tobacco User Group Least Square Means (LSMs)
| Regression results | Tobacco users group LSM differences and ratios | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Predictor | Level | N | Coefficient [95% CI] | Exponentiated coefficient [95% CI] | p | Group A | Group B | A–B [95% CI] (ln) | Ratio A/B [95% CI] | Adjusted pa |
| Tobacco user group | Combustible | 5576 | 4.17 [4.02, 4.31] | 64.5 [55.7, 74.6] | <.0001 | Combustible | Never | 4.17 [3.94, 4.39] | 64.5 [51.5, 80.7] | <.0001 |
| E-Cig | 258 | 1.32 [1.05, 1.58] | 3.73 [2.87, 4.85] | <.0001 | E-Cig | Never | 1.32 [0.913, 1.72] | 3.73 [2.49, 5.58] | <.0001 | |
| Smokeless | 476 | 5.94 [5.69, 6.20] | 382 [296, 491] | <.0001 | Former | Never | 0.727 [0.348, 1.10] | 2.07 [1.42, 3.02] | <.0001 | |
| Poly | 2572 | 4.88 [4.73, 5.02] | 131 [114, 151] | <.0001 | Poly | Never | 4.88 [4.66, 5.10] | 131 [105, 163] | <.0001 | |
| Former | 559 | 0.727 [0.477, 0.976] | 2.07 [1.62, 2.65] | <.0001 | Smokeless | Never | 5.94 [5.56, 6.33] | 382 [259, 562] | <.0001 | |
| Never | 1563 | Ref. | Combustible | Former | 3.44 [3.05, 3.83] | 31.2 [21.1, 46.1] | <.0001 | |||
| Sex | Male | 5953 | Ref. | E-Cig | Former | 0.589 [0.0702, 1.11] | 1.80 [1.07, 3.03] | .0139 | ||
| Female | 5051 | 0.145 [0.0316, 0.258] | 1.16 [1.03, 1.29] | .0126 | Combustible | Smokeless | −1.78 [−2.10, −1.45] | 0.169 [0.122, 0.234] | <.0001 | |
| Age group | 18–24 | 3541 | −0.649 [−0.796, −0.502] | 0.523 [0.452, 0.604] | <.0001 | E-Cig | Smokeless | −4.63 [−5.12, −4.14] | 9.77E−03 [5.98E−03, 0.0160] | <.0001 |
| 25–34 | 2341 | Ref. | Former | Smokeless | −5.22 [−5.73, −4.71] | 5.42E−03 [3.26E−03, 9.01E−03] | <.0001 | |||
| 35–54 | 3352 | 0.315 [0.137, 0.493] | 1.37 [1.15, 1.63] | .0007 | Poly | Smokeless | −1.07 [−1.39, −0.747] | 0.344 [0.250, 0.474] | <.0001 | |
| 55+ | 1770 | 0.143 [−0.0249, 0.310] | 1.15 [0.977, 1.36] | .0944 | Combustible | Poly | −0.711 [−0.856, −0.566] | 0.491 [0.425, 0.568] | <.0001 | |
| Race/ethnicity | HA | 1845 | −0.866 [−1.04, −0.693] | 0.421 [0.354, 0.499] | <.0001 | E-Cig | Poly | −3.56 [−3.95, −3.17] | 0.0284 [0.0193, 0.0418] | <.0001 |
| NHB | 1667 | 0.0494 [−0.136, 0.235] | 1.05 [0.874, 1.26] | .599 | Former | Poly | −4.15 [−4.57, −3.73] | 0.0158 [0.0104, 0.0239] | <.0001 | |
| NHW | 6608 | Ref | Combustible | E-Cig | 2.85 [2.48, 3.22] | 17.3 [11.9, 25.1] | <.0001 | |||
| OTH | 884 | −0.235 [−0.475, 3.57E−03] | 0.790 [0.624, 1.00] | .0535 | ||||||
| Education | <HS/GED | 2717 | 0.225 [0.0650, 0.386] | 1.25 [1.07, 1.47] | .0064 | |||||
| HS | 2735 | Ref. | ||||||||
| <4 y college/associate | 4084 | −0.486 [−0.640, −0.332] | 0.615 [0.529, 0.716] | <.0001 | ||||||
| Bachelors | 1025 | −1.41 [−1.62, −1.21] | 0.244 [0.199, 0.298] | <.0001 | ||||||
| Advanced | 443 | −1.61 [−1.86, −1.36] | 0.199 [0.156, 0.255] | <.0001 | ||||||
| Creatinine, urine (Ln) | Continuous | 0.515 [0.438, 0.592] | 1.67 [1.55, 1.81] | <.0001 |
CI = confidence interval; GED = General Educational Development; HA = Hispanic; HS = high school; LSM = Least Square Mean; NHB = non-Hispanic Black; NHW = non-Hispanic White; NNAL = 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol; OTH = Other Hispanic/Other Race/Multiracial.
Combustible: combustible exclusive user. E-Cig: e-cigarette exclusive user. Smokeless: smokeless exclusive user. Poly: poly user. Former: former user. Never: never user.
aBonferroni corrected for multiple comparisons.