Smoking prevalence following the announcement of tobacco tax increases in England between 2007 and 2019: an interrupted time–series analysis

AIMS: This study aimed to evaluate the impact of announcement of tax increases on factory‐made (FM) and roll‐your own (RYO) cigarettes in England. DESIGN, SETTING AND PARTICIPANTS: Autoregressive integrated moving average with exogeneous input (ARIMAX) time–series modelling in England, UK. Data were aggregated monthly on 274 890 participants between 2007 and 2019 taking part in the Smoking Toolkit Study (STS). MEASUREMENTS: The association of sustained step level changes for tax rises for FM cigarettes and temporary pulse effects for tax rises for RYO cigarettes with smoking, quit attempt and quit success prevalence as well as per‐capita self‐reported cigarette consumption and cost per cigarette was assessed. FINDINGS: A 10% rise in tax on RYO cigarettes was associated with a temporary 21.1% decline [95% confidence interval (CI) = –30.4 to −10.7] in smoking prevalence, and 20.7% decline (95% CI = –32.4 to −7.0) in per‐capita self‐reported cigarette consumption; while a 3% rise of tax on RYO cigarettes was associated with a temporary 20.7% decline (95% CI = –33.3 to −5.8) in the amount paid per RYO cigarette. For tax increases on FM cigarettes, a 5% above inflation tax rise was associated with a step‐level increase of 33.1% (95% CI = 18.4–49.5) in quit success rates. However, some of the findings were sensitive to model specification and temporally specific. CONCLUSION: The announcements of tax increases for cigarettes in England between 2010 and 2019 were inconsistently associated with temporary reductions in smoking prevalence, per‐capita self‐reported cigarette consumption and improved quit success. Paradoxically, reductions in the cost for roll‐your‐own cigarettes were also found. The results were not robust in all sensitivity analyses.