The ID effect on youth access to cigarettes

To estimate the effect on cigarette sales rates when minors present identification (ID).

Controlled experiment in which minors attempting to purchase cigarettes either carried a valid photo ID (documenting they were minors) or carried no ID, and were instructed to show the ID or admit having no ID if the clerk requested proof of age.

Census of retail stores in six urban and suburban Colorado counties.

Retail cigarette clerks, uninformed of the study.

Relative risk (RR) of cigarette sale to a minor when ID was requested and presented versus requested but not presented.

When clerks requested ID, sales were more than six times as frequent if minors presented ID than if they did not (12.2% v 2.0%, RR 6.2, p < 0.0001). The relative risk remained substantially unchanged under adjustment for demographic and circumstantial covariates.

Presentation of photo ID in compliance checks increases illegal cigarette sales to minors. The impact may vary among states or locales and depends strongly on how often clerks request proof of age. Clerk training and responsible cigarette sales practices should include age calculations from photo ID. Programmes relying on investigative purchase attempts to estimate actual rates of cigarette sales to minors should ascertain and replicate local ID presenting behaviours that minors typically use during genuine attempts to buy cigarettes.