Smoking cessation in COPD patients: (cost-)effectiveness of the smokestoptherapy and validation of abstinence

The prescribed cut-off points for all three CO monitors generate misleading results concerning the determination of the smoking status in both populations after a 12-hour period of abstinence. For the measurement of CO over time, it can be concluded that smokers are able to deceive CO monitors by short-time abstinence, unless the cut-off points are being adjusted properly. The optimal cut-off points depend upon the goal of the study but salivary cotinine measurements outperforms the CO measurements and can therefore be considered the `gold standard¿. Cotinine measurements are relatively costly; a cost-effective validation procedure combining both tools is therefore recommended.