The Lifetime Mortality Implications of Vaping and Smoking Initiated During Adolescence.

INTRODUCTION: Whether, and if so how much, adolescent vaping increases the risk of future premature mortality is unknown. METHODS: This microsimulation model and Monte Carlo analysis evaluated plausible lifetime vaping- and smoking-associated mortality outcomes with vaping and smoking initiated during adolescence for the 4.1 million U.S. 12-year-olds in 2016. Outcomes with e-cigarettes available throughout life were compared with a counterfactual in which e-cigarettes never existed. The analysis considered three ways vaping could impact mortality: (i) vaping during adolescence followed by smoking continuing into adulthood; (ii) vaping continuing into adulthood without smoking; and (iii) vaping increasing adult smoking cessation for cohort members who began smoking in adolescence. Parameters included vaping's mortality risk (5%-30% that of smoking), the smoking cessation increase attributable to vaping (0%-30%), the vaping cessation rate (1-4 times the smoking cessation rate), and years of vaping after vaping-induced smoking cessation (5-20). Data were collected in 2024 and analyzed in 2024-2025. RESULTS: E-cigarette availability was associated with the average cohort member's vaping-associated lifetime probability of premature mortality ranging from an increase of 0.44 percentage points to a decrease of 0.06 percentage points, corresponding, respectively, to a loss of ≤31.3 days of life expectancy to a gain of ≤2.7 days. In two illustrative model setups, individuals who smoked at age 20 years had a lifetime probability of premature mortality of 7-8%. Those who vaped but did not smoke had a probability of 0.15-0.84%. CONCLUSIONS: If youth vaping affects lifetime premature mortality, the increase or decrease is projected to be very small.