The potential impact of a low-nitrosamine smokeless tobacco product on cigarette smoking in the United States: estimates of a panel of experts.

OBJECTIVE To predict the impact on tobacco use in the US of a "harm reduction" policy that requires that the smokeless tobacco product meet low nitrosamine standards, but could be marketed with a warning label consistent with the evidence of relative health risks. METHODS Low nitrosamine smokeless tobacco (LN-SLT) and cigarette use are predicted by a panel of experts using a modified Delphi approach. We specify a thought experiment to isolate the changes that would occur after the new LN-SLT policy was implemented. RESULTS The panel predicted that the new policy would accelerate a decrease in smoking prevalence from 1.3 to 3.1 percentage points over 5 years compared to the current SLT product policy, with greater effects on males than females. Introduction of the new product was also predicted to result in modest additional use of SLT overall, with the greatest increases among males who initiated tobacco use under the new policy. CONCLUSION An overall consensus was reached that the introduction of a new LN-SLT product under strict regulations would increase SLT use, but reduce overall smoking prevalence. This reduction would likely yield substantial health benefits, but uncertainties surround the role of marketing and other tobacco control policies.