Outcome | Quality of Evidence | Factors that Increase Quality | Factors that Reduce Quality | Supporting Evidence |
---|---|---|---|---|
Sale | ||||
Reduced sales of ENDS | Moderate | Dose-response gradient (ban on all ENDS vs. flavours) (+ 1) Large magnitude of effect (+ 2) | Limitations in study design (− 1) Potential publication bias (− 1) | Ali (2022), Gammon (2021), Katchmar (2021), Liber (2021) [28,29,30,31] |
Increased sales of combustible cigarettes | Low | Dose-response gradient (ban on all ENDS vs. flavours) (+ 1) Moderate magnitude of effect (+ 1) | Inconsistent findings (− 1) Limitations in study design (− 1) | Gammon (2021), Katchmar (2021), Liber (2021), Xu (2022) [28,29,30, 33] |
Behaviour | ||||
Reduced consumption of any tobacco use | Low | Moderate effect sizes across studies (+ 1) | Inconsistencies in measurement rigour (differing definitions of product use) (− 1) Low measurement rigour (− 1) | Kingsley (2019, 2021), Olsen (2022), Yang (2022) [38,39,40,41] |
Reduced ENDS consumption | Low | Moderate effect sizes across studies (+ 1) | Inconsistencies in measurement rigour (differing definitions of product use) (− 1) Low measurement rigour (− 1) | Hawkins (2021), Kingsley (2019), Liu (2022), Yang (2020) [35, 38, 39, 42] |
Increased combustible cigarette consumption | Very Low | Large magnitude of effect (+ 2) | Limitations in study design (− 1) Inconsistency in controls for bias risk (− 1) Inconsistent findings (− 1) Low measurement rigour (differing definitions of product use) (− 1) | Friedman (2021), Hawkins (2021), Kingsley (2019), Liu (2022), Yang (2022) [34, 35, 38, 39, 42] |
Compliance | ||||
Reduced availability of flavoured products | Moderate | Dose-response gradient (difference in enforcement) (+ 1) Large magnitude of effect across studies (+ 2) | Limitations in study design (−1) Inconsistencies in measurement rigor (short-term follow-up) (− 1) | Amalia (2020, 2020), Andersen-Rodgers (2021), Brock (2019), Gaiha (2021), Holmes (2022), Kephart (2020), Kingsley (2019), Nali (2021), Vyas (2021) [39, 53,54,55,56,57,58,59,60,61] |