A new US study published by the scientific journal Addiction has found that a high proportion of smokers enrolled in stop-smoking programs during a hospital stay report having quit when in fact they have not. The findings mean that in these kinds of study it is vital to check claims of having quit using an objective measure.
This nationwide study followed five large smoking cessation clinical trials in the US that enrolled smokers at hospitalization. At 6-month follow-up, 822 participants (out of 4,206 who completed the follow-up survey) reported they had not smoked in the past 7 days and provided a usable saliva sample for verification by testing for a chemical called ‘cotinine’. The liver converts nicotine in the body to cotinine and so this chemical is a very accurate measure of whether someone has smoked in the past few days. More than 40% of those 822 self-reported quitters failed the saliva test.