Method for Estimating Non-study Cigarette Use among Switchers to Low Nicotine Content Cigarettes in Ambulatory Clinical Studies

study. In addition, based on the observed levels of urinary cotinine, a biomarker of exposure (BOE) to nicotine, the authors showed that study participants substantially under-reported the prevalence of non-study cigarette use During week 6 of the study alone, 39% of participants assigned to cigarettes with 0.4 mg/g nicotine (about 98% lower than CNC) self-reported smoking non-study cigarettes, whereas urinary cotinine assessment showed that 76-78% of them were non-compliant The difference between the expected and observed levels of urinary total nicotine equivalents (nicotine plus its major metabolites, TNE) also provides an indication on the degree of under-reporting of the magnitude of non-study cigarette use (i.e., number of cigarettes smoked per day [CPD]). The urinary TNE levels for the study group assigned the 0.4 mg/g VLN cigarettes were expected to be 0.5 nmol/mg creatinine if the participants were compliant by exclusively smoking the assigned study cigarettes However, the actual TNE level was reported to be 30 times higher at 15 nmol/mg creatinine The most plausible explanation is that