Objective: To determine if the standard compliance check protocol is a valid measure of the experience of underage smokers when purchasing tobacco in unfamiliar communities.
Setting: 160 tobacco outlets in eight Massachusetts communities where underage tobacco sales laws are vigorously enforced.
Procedure: Completed purchase rates were compared between underage smokers who behaved normally and inexperienced non-smoking youths who were not allowed to lie or present proof of age (ID).
Results: The "smoker protocol" increased the likelihood of a sale nearly sixfold over that for the non-smokers (odds ratio (OR) 5.7, 95% confidence interval (CI) 1.5 to 22). When the youths presented an ID with an underage birth date, the odds of a completed sale increased dramatically (OR 27, 95% CI 3.4 to 212). Clerks judged to be under 21 years of age were seven times more likely to make an illegal sale (OR 7.6, 95% CI 2.4 to 24.0).
Conclusions: Commonly used compliance check protocols are too artificial to reflect accurately the experience of underage smokers. The validity of compliance checks might be improved by having youths present ID, and by employing either tobacco users, or non-tobacco users who are sufficiently experienced to mimic the self confidence exhibited by tobacco users in this situation. Consideration should be given to prohibiting the sale of tobacco by individuals under 21 years of age.