All smokers’ behavior is not the same. We and others has identified five trajectories of smoking behavior over time among youth and young adults based on demographic characteristics (graph above). Now Dorie Apollonio, Lauren Dutra and I have expanded this work to include the effects of changing tobacco control policies — smokefree laws and taxes — over time on these trajectories. just published “Associations between smoking trajectories, smoke-free laws and cigarette taxes in a longitudinal sample of youth and young adults” in PLOS One.
We anticipated that smoke-free laws would reduce the risk of tobacco initiation and use across all smoking trajectories and that tax increases would reduce the risk of initiation among never smokers but not reduce use among current established smokers.
What we found was that as the probability of being covered by comprehensive smoke-free law increased, predicted days of use in a month decreased for people on 4 or the 5 trajectories. The effect was most substantial for quitters and never smokers and was also associated with reduced days of smoking in a month for late escalators and early established smokers . Experimenters were the exception, in all trajectories other than experimenters, where coverage by comprehensive smoke-free laws was associated with more days of smoking.
As tax rates increased, risk of initiation and days of smoking per month decreased in less established users. The effects were most substantial for experimenters, never smokers and quitters. In contrast, days of use increased for both late escalators and early established smokers.
These results also suggest that further interventions are needed to increase the efficacy of tax increases for early established smokers and late escalators. Methods to increase tobacco price increases beyond tax increases, such as minimum floor prices or banning coupons and price promotions, may be more effective deterrents for established smokers and late escalators.
It is possible to compare the magnitude of the impacts of these to policies by computing the tax equivalent of a smoke-free law. The largest effect was on quitters, where the smoke-free law was equivalent to a tax well over $1,000, reflecting the fact that the estimated effect of taxes after quitting was so small. The next largest comparative effect was among never smokers, where a smoke-free law was equivalent to a $11.06 tax. The tax-equivalent effects of smoke-laws were more modest among late escalators ($0.85) and early established smokers ($0.52). The equivalent tax effect of smoke-free laws on experimenters was much smaller ($0.08).
These findings suggest that, contrary to the mantra that “tax increases are the most effective tobacco control policy,” for most people smoke-free laws have bigger effects that tax increases in the range that are typically enacted. The one major exception to this is among experimenters, where tax increases seem to be the more potent intervention.
Of course, given the different sensitivities of different types of smokers to the two policies, a comprehensive approach that combines strong smokefree-laws with substantial tax increases would be the most effective intervention.
Here is the abstract:
Cigarette smoking patterns vary within the population, with some individuals remaining never smokers, some remaining occasional users, and others progressing to daily use or quitting. There is little research on how population-level tobacco control policy interventions affect individuals within different smoking trajectories. We identified associations between tobacco control policy interventions and changes across different smoking trajectories among adolescents and young adults. Using 15 annual waves of data drawn from the National Longitudinal Survey of Youth 1997 (NLSY97), we applied a group-based trajectory model to identify associations between days smoked per month, comprehensive smoke-free laws, cigarette tax rates, and known socio-demographic risk factors for membership in different smoking trajectories. Comprehensive smoke-free laws were associated with reduced risk of initiation and reductions in days smoked per month for all trajectories other than occasional users. Higher tax rates were associated with reduced risk of initiation and days smoked for all trajectories other than established users. Overall, population-based tobacco control policies, particularly comprehensive smoke-free laws, were associated with reduced smoking. Tobacco taxes primarily reduced risk of initiation and use among never smokers, experimenters, and quitters, consistent with previous research suggesting that tobacco manufacturers lower prices after tax increases to reduce the cost of continued smoking for established users. These results provide support for expanding smoke-free laws and establishing a minimum tobacco floor price, which could improve public health by reducing the risk of initiation as well as use among occasional and established smokers.
The full citation is: Apollonio DE, Dutra LM, Glantz SA. Associations between smoking trajectories, smoke-free laws and cigarette taxes in a longitudinal sample of youth and young adults. PLoS ONE 16(2): e0246321. https://doi.org/10.1371/journal.pone.0246321. It is available here.