Estimated effect sizes of PWLs on smoking prevalence, cessation and initiation*
| Type of effect | Best estimate | Lower bound | Upper bound | Primary studies/data used to derive estimates |
|---|---|---|---|---|
| Initial effect on prevalence rates | 4% reduction | 2% reduction | 8% reduction | Azagba and Sharaf,51 Huang et al,20 Thrasher et al,55 prevalence data from the UK52 and Australia54 |
| Effect on future cessation rates | 10% increase | 5% increase | 20% increase | Azagba and Sharaf,51 Hammond et al,5 Hammond et al,57 Brewer et al,59 Noar et al,39 Shanahan and Elliott,58 Partos et al,60 Li et al 57 |
| Effect on future initiation rates | 6% reduction | 2% reduction | 12% reduction | Shanahan and Elliott,58 Environics Research Group Limited,64 EC,65 Koval et al,66 Noar et al,40 O'Hegarty et al,67 Villanti et al,19 prevalence data from Canada,68 Australia54 and England69 |
*All effect sizes are measured relative to the current levels of the respective rates.
PWLs, pictorial warning labels.