Objectives Develop a method that yields high rates of sensitivity and specificity for determination of counterfeit cigarette packs for three popular brands: Newport, Marlboro (‘Red’) and Marlboro Gold.

Methods Using systematic keyword searches, we identified industry documents from the University of California, San Francisco's Legacy Tobacco Documents Library that describe the use of ultraviolet (UV) irradiation and close examination of printing quality to distinguish between counterfeit and genuine cigarette packs. Guided by these documents, we identified six markers for counterfeit cigarettes across three popular brands using counterfeit cigarette packs (N=68) seized by law enforcement agencies in the USA. We assessed the diagnostic test accuracy of these markers and tested it against genuine packs (N=22) using receiver operating characteristic curves analysis.

Results We find that counterfeit cigarette packs fluoresce to long-wave UV irradiation and display poor printing quality. The optimal cut-off value varies among the three brands. For example, counterfeit Newport and Marlboro packaging can be reliably classified with two of six characteristics, while Marlboro Gold requires four.

Conclusions Researchers who conduct littered pack and pack swap studies are urged to include this method to assess the share of counterfeit cigarettes, and compare the result against tobacco industry figures.