The effect of cigarette and e-cigarette taxes on prescriptions for smoking cessation medications

Objective To test the effect of cigarette and e-cigarette taxes on prescriptions for smoking cessation medications. Data Source Symphony Health, IDV all-payer prescription claims data for the United States over the period 2009-2017. Prescription fills for smoking cessation products were provided at the patient's age, patient's sex, brand/generic, payment type, year, and quarter levels. Study Design We study the effect of state-level cigarette and e-cigarette tax rates on prescriptions for smoking cessation medications using two-way fixed effect modified difference-in-differences regressions. We also use a multiperiod difference-in-differences estimator robust to bias from dynamic and heterogeneous treatment effects with a staggered policy rollout. Data Collection/Extraction Methods We use fills for Chantix, Zyban, and their generics, as well as Food and Drug Administration-approved nicotine replacement therapies that are paid for by insurance. Principal Findings We observe no statistically significant change in prescription fills following an increase in the e-cigarette tax rate, though we are unable to rule out potentially large effects. However, following a $1.00 increase in the cigarette tax rate, we observe a 1052 increase in prescription fills per 100,000 adults (95% CI: 57, 2046; 4.2% increase). The effect of cigarette taxes on prescription fills was particularly large for 18-34 year-olds. Conclusions Our findings suggest that, during a period when e-cigarettes are widely available, cigarette tax increases remain effective in increasing use of these medications, but e-cigarette taxes do not increase use of these medications.