Table 1.

Differences in average biomarker values across smoker groups

DS (n = 222)ITS (n = 224)ITS vs. DSCITS (n = 131)NITS (n = 67)CITS vs. NITS
BiomarkerMean (SE) [median]Mean (SE) [median]PMean (SE) [median]Mean (SE) [median]P
CPD (weighted past 3 days)14.67 (0.42) [14.71]3.42 (0.23) [2.29]<0.00013.74 (0.31) [2.71]2.25 (0.29) [1.43]<0.001
Cotinine (ng/mL)1395.50 (69.43) [1298.87]478.12 (43.90) [219.71]<0.001562.81 (61.06) [340.74]314.26 (66.44) [118.48]<0.01
 Statistically adjusted for CPDa968.35 (74.65)890.66 (73.02)0.53526.81 (49.21)446.22 (66.53)0.34
 Cotinine/CPD104.01 (5.33) [87.48]202.30 (43.46) [78.90]<0.05b180.69 (23.25) [83.96]270.85 (134.20) [67.88]0.73b
NMR5.09 (0.31) [3.70]5.10 (0.28) [3.98]0.255.17 (0.42) [3.90]4.89 (0.34) [4.24]0.74
CO (ppm)21.06 (0.74) [20.33]7.19 (0.47) [4.11]<0.0018.04 (0.65) [6.00]5.31 (0.65) [3.25]<0.01
 Statistically adjusted for CPDa13.70 (0.86)13.92 (0.83)0.557.54 (0.50)7.10 (0.69)0.18

NOTE: All descriptive statistics and t tests are weighted by race.

  • aControlling for linear and quadratic CPD.

  • bStatistical tests conducted on square-root–transformed values.