Author Contributions: Dr DiFranza had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study concept and design: DiFranza, Ockene, and McNeill. Acquisition of data: DiFranza, Hazelton, Friedman, Dussault, and Wood. Analysis and interpretation of data: DiFranza, Savageau, Fletcher, O’Loughlin, Pbert, McNeill, and Wellman. Drafting of the manuscript: DiFranza, Savageau, Fletcher, O’Loughlin, Pbert, and Wellman. Critical revision of the manuscript for important intellectual content: DiFranza, Savageau, Fletcher, O’Loughlin, Pbert, Ockene, McNeill, Hazelton, Friedman, Dussault, Wood, and Wellman. Statistical analysis: Savageau, Fletcher, and O’Loughlin. Obtained funding: DiFranza and Ockene. Administrative, technical, and material support: DiFranza and Savageau. Study supervision: DiFranza and Dussault.