Reacción a "Reactions to a study on the use of e-cigarettes for smoking cessation"

The study has important limitations:  

• A very important limitation in this study is blinding. The nursing staff is in charge of implementing the intervention and assessing the results, and is not blinded to the group to which the participants belong. They should have been in order to ensure that the intervention and follow-up were exactly the same between groups. In this study, the nurses know which patient they are following by telephone (whether the participant receives e-cigarettes or standard treatment), and can therefore modulate the intervention.  
• The intervention is not strictly comparable between groups and is not recorded in detail. The comparison group is given 50 euros to spend on whatever they want, but it is not known whether they have spent it on detoxification treatments. In addition, the complementary intervention with nicotine patches seems not to be recorded, so it is not clear how many people in both the intervention and control groups have used nicotine patches, what type and for how long.  
• It would have been interesting to have a comparison group with pharmacological treatment.  
• It has not been recorded which nicotine device the subjects in the intervention group have chosen. In other words, it could be the case that they are receiving more nicotine in e-cigarettes than with the conventional cigarette they were using before the intervention. This is a key fact that we do not know.  
• In the assessment of the main outcome there are many losses, understood as the lack of biochemical verification of abstinence. This casts doubt on the validity of the results, as we do not know the causes of these losses.  

There is a 12% difference in abstinence duration in favour of the e-cigarette. This magnitude is relatively small and we do not know if it is due to the possible greater addiction in some versus others. This is also counterbalanced by the greater adverse effects in the intervention group.  

It is very striking that the study, which has completed fieldwork in 2021, is only reported to give results at six months, when it is indicated that the follow-up would be much longer term. However, none of this information is given, when the data should already be available, as at least two years have passed for all participants. The reasons for this omission of information should be given.   

There are also issues related to the subjects included. They are relatively young smokers (only 25% are older than 50 years), have limited addiction (Fagerstrom scale 4 out of 10), and a high educational level. This does not represent the standard smoker, who smokes much more, has a higher addiction and a lower educational level.  

In conclusion, while suggesting that e-cigarettes may be beneficial for smoking cessation, this study has several limitations and its results should be taken with caution.