TABLE 1

Randomised controlled trials (RCTs) comparing nicotine-containing electronic cigarettes with nicotine replacement therapy (NRT), varenicline and behavioural support/counseling

InterventionComparison groupNumber of RCTs includedResultCertainty of evidence (GRADE)
E-cigarette with nicotineNRT3E-cigarette with nicotine significantly betterModerate
E-cigarette with nicotineVarenicline1Varenicline significantly betterNot assessed
E-cigarette with nicotineBehavioural support/no support4E-cigarette with nicotine significantly betterVery low
E-cigarette with nicotineE-cigarette without nicotine3E-cigarette with nicotine significantly betterModerate
E-cigarette with nicotine + NRTE-cigarette without nicotine + NRT2E-cigarette with nicotine significantly betterNot assessed
E-cigarette with nicotine + NRTNRT1No significant differenceNot assessed