Table 3.

Change in total cotinine and total NNAL from before to after the smoking ban (n = 24)

BiomarkerMedian percent decrease after the banGeometric mean of before/after (95% CI)Median difference (before minus after)P (before minus after)
Total cotinine ng/mL*83.3%12.3 (5.7-26.6)11.0<0.001
Total cotinine ng/mg creatinine78.6%9.3 (5.1-16.9)6.9<0.001
Total NNAL pmol/mL*76.6%21.4 (6.2-73.7)0.039<0.001
Total NNAL pmol/mg creatinine56.5%19.8 (5.4-72.8)0.0180.001

Abbreviation: CI, confidence interval.

  • *Unadjusted for creatinine.

  • Adjusted for creatinine; total cotinine LOD, 1.0 ng per mg creatinine; total NNAL LOD, 0.0025 pmol per mg creatinine.