Temporal changes of under-reporting of cigarette consumption in population-based studies

The difference in cigarette consumption between legal sale and self-reported data has substantially increased over the last two decades in Italy, reflecting increasing under-reporting of cigarette consumption mainly due to a decreasing social acceptability of smoking. Comparisons between interview-based and legal sale data are complicated by factors such as smuggling control and changes in the population (eg, increased proportion of immigrants); however these are able to justify only a small proportion of the gap found in Italy.