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Positive impact of Tobacco 21 policies grossly underestimated

December 20, 2024
by Megan Kernis

Yale study estimates raising the age for tobacco sales to 21 could avert more than 525,000 deaths, more than double prior estimates

In 2020, the federal minimum age for buying tobacco products was officially raised from 18 to 21 as an increasing number of states and localities across the country sought to raise the age for tobacco purchases to protect the health of young adults.

One of the driving factors behind the change was a 2015 report from the National Academy of Medicine (NAM) that found that a federal Tobacco 21 (T21) law could prevent as many as 249,000 deaths through the year 2100.

A new study led by Yale researchers with the Cancer Intervention and Surveillance Modeling Network (CISNET) Lung Working Group has now determined that the NAM report grossly underestimated the number of averted deaths. The findings significantly amplify the potential impact of the T21 law and provide important new information for future state and local policy discussions surrounding tobacco regulation and public health.

The modeling study estimates that comprehensive enforcement of local, state, and federal T21 laws could result in up to 526,000 premature smoking-attributable deaths being averted across the United States and 13.3 million life-years gained through 2100. The findings more than double the estimate provided in the NAM report.

The Yale study was published in JAMA Health Forum on December 20, the fifth anniversary of the signing of the U.S. T21 law.

The researchers said NAM’s lower projection was likely due to the fact that the report based its estimate on U.S. data that was available when only 30 municipalities had adopted policies increasing the age for tobacco sales. The NAM report also failed to account for each state’s smoking and mortality rates, population size, and policy implementation timeline – factors that influence policy outcomes.

The CISNET modeling study, by comparison, incorporated comprehensive state data on smoking patterns, mortality, and T21 policy implementation at the local, state, and federal levels. These detailed data, in addition to rigorous evidence on the effects of T21 policies, were used as inputs for simulation models developed for each of the 50 states and the District of Columbia. Because it takes decades before changes in smoking behavior translate into disease and deaths, simulation models were used to understand the potential long-term effects of smoking prevention policies.

Among the 50 states, New York and Massachusetts were top ranked in relative mortality reductions for their early and widespread adoption of T21 policies at the local level, the study found. Hawaii, as the first state to implement T21, also had higher relative mortality reductions compared to states that were slower to implement the law.

“We felt it was important to quantify the benefits of Tobacco 21 policies and to give credit where it’s due,” said Dr. Jamie Tam, PhD, assistant professor of public health (health policy) at the Yale School of Public Health and the study’s lead author. “Local communities and states that pushed for Tobacco 21 policies early on reap those benefits down the road. Our models use real-world policy data to reflect that.”

The simulation findings varied widely by state and reflect geographic disparities, where less healthy states like Ohio—which have higher mortality and lower life expectancy—have more to gain from T21 policies than healthier states like California which already have relatively low smoking rates. Eight states currently do not have their own state T21 laws, and instead rely solely on enforcement of the federal law.

To help inform states and localities considering changes in the regulation of tobacco sales, the CISNET team designed a policy simulation model called the Tobacco Control Policy (TCP) tool. The free interactive website allows users to compare smoking and mortality outcomes under a baseline scenario with those under a specific policy scenario. A previous version of the TCP tool used T21 policy effects from the NAM report, while the new version is now based on real-world T21 policy data and state-specific simulations.

Other collaborators on the study included Alyssa Crippen, PhD, Abigail Friedman, PhD, and Theodore R. Holford, PhD, all from the Yale School of Public Health, as well as experts from British Columbia Cancer Research Institute, University of Michigan, Georgetown University, and the Preventing Tobacco Addiction Foundation/Tobacco 21.