Aim:
To monitor how switching to e-cigarettes from cigarette smoking affects psychometric and clinical parameters and relapse rate over a period of 4 weeks.

Methods:
Heavy smokers (≥10cig/day) attended 6 visits where psychometric parameters associated with craving, nicotine withdrawal symptoms, sleep and quality of life were monitored using well validated questionnaires. Heart rate and blood pressure were also measured at each visit. Visit 1 and 2 were baseline visits where smokers continued to smoke and then asked to quit and transition to e-cigarette use. The subsequent visits occurred 3, 7, 21 and 28 days after the quit date. Compliance was monitored via exhaled CO. Completed participants received weekly questionnaires for 12 months and two follow up calls 6 and 12 months after their final visit to monitor for relapse.

Results:
One month relapse rate amongst eligible participants (n=29) was 28%. At 6 months (n=5), 40% used either e-cigarettes or nothing (non-relapsers) and 60% partially relapsed or were dual users. Repeated measures One-Way ANOVA(n=20) showed a significant effect for parameters: ‘irritability’ (p<0.01), and Pittsburgh Sleep Quality Index (p<0.01). Moreover, there was a significant reduction in nicotine withdrawal at visit 6 vs. visit 3 (p<0.01) and 4 (p<0.05). There was also a significant reduction in urge to smoke at visit 6 vs visit 1 (p<0.05) and in the strength of urges to smoke at visit 6 vs visit 1 (p<0.01), at visit 5 and 6 vs visit 2 (p<0.05 and p<0.01, respectively), as well as at visit 6 vs visit 3 (p<0.05). Additionally, a decrease in heart rate at visit 3 vs visit 1 was detected (p<0.05). No significant effect was observed in the other parameters.

Conclusions:
Switching to e-cigarettes quickly induces beneficial changes in some psychometric and cardiovascular parameters, thus providing evidence for their use as a smoking cessation method.

Funding:
This work was funded by the Europe Commission under Horizon 2020.