How generalisable to community samples are clinical trial results for treatment of nicotine dependence: a comparison of common eligibility criteria with respondents of a large representative general population survey.

OBJECTIVE: To examine the generalisability of findings from clinical trials of individuals with nicotine dependence to a large general population sample.
METHODS: Eligibility criteria were drawn from typical criteria of clinical trials for nicotine dependence. The National Epidemiological Survey on Alcohol and Related Conditions (NESARC), a large national sample of the US population, was used to assess how many potentially eligible people would fulfil the eligibility criteria. NESARC interviewed more than 43,000 adults aged 18 years and older. We applied a standard set of eligibility criteria representative of smoking cessation clinical trials to all the 4962 adults with nicotine dependence in the past 12 months, and then to a subgroup of participants motivated to quit (n=4121).
RESULTS: We found that approximately six out of 10 participants (65.89%) with nicotine dependence were excluded by at least one criterion. In the subgroup of nicotine-dependent participants motivated to quit, more than half (58.60%) were excluded by at least one criterion. For the overall sample, smoking 10 cigarettes per day or less and lack of motivation to quit were the two criteria leading to exclusion for the greatest percentage of individuals (32.02% and 17.60%, respectively). For the sample motivated to quit, smoking 10 cigarettes or fewer per day and current depression led most frequently to exclusion (33.79% and 15.71%, respectively).
CONCLUSIONS: Further studies and interventions should explore the efficacy of tobacco treatment interventions in a larger segment of the population, notably in the subpopulations of people with nicotine dependence who smoke fewer than 10 cigarettes per day or who have comorbid depression.