Domain	Judgement	Support for judgement
Bias due to confounding	Serious	Plausible other events could have affected outcomes and no attempt to adjust for such confounding. Limited number (5) of pre‐intervention time points to determine trend.
Bias in selection of participants into the study	Low	Risk of selection bias is unlikely as comprehensive sales data was used.
Bias in classification of interventions	Serious	Joinpoint regression was used to determine pre‐ and postintervention time points, which selects interruption based on outcome data. They also present post‐trend, after 2016 identified as key point, but no analysis of change in that trend.
Bias in deviations from intended  interventions	Low	No particular deviations from intended intervention (introduction of heated tobacco to market).
Bias due to missing data	Low	Sales data were reasonably complete.
Bias in measurement of outcomes	Low	Recording of sales data and associated measurement error unrelated to introduction of heated tobacco to market.
Bias in selection of reported result	Moderate	Outcome measures and analyses unregistered, but clearly defined and consistent.