Smoking cessation and reduction in schizophrenia (SCARIS) with e-cigarette: study protocol for a randomized control trial

Abstract

Background: It is well established in studies across several countries that tobacco smoking is more prevalent among schizophrenic patients than the general population. Electronic cigarettes are becoming increasingly popular with smokers worldwide. To date there are no large randomized trials of electronic cigarettes in schizophrenic smokers. A well-designed trial is needed to compare efficacy and safety of these products in this special population.

Intervention: We have designed a randomized controlled trial investigating the efficacy and safety of electronic cigarette. The trial will take the form of a prospective 12-month randomized clinical study to evaluate smoking reduction, smoking abstinence and adverse events in schizophrenic smokers not intending to quit. We will also monitor quality of life, neurocognitive functioning and measure participants' perception and satisfaction of the product.

Outcome measures: A ≥50% reduction in the number of cigarettes/day from baseline, will be calculated at each study visit ("reducers"). Abstinence from smoking will be calculated at each study visit ("quitters"). Smokers who leave the study protocol before its completion and will carry out the Early Termination Visit or who will not satisfy the criteria of "reducers" and "quitters" will be defined "non responders".

Statistical analysis: The differences of continuous variables between the three groups will be evaluated with the Kruskal-Wallis Test, followed by the Dunn multiple comparison test. The differences between the three groups for normally distributed data will be evaluated with ANOVA test one way, followed by the Newman-Keuls multiple comparison test. The normality of the distribution will be evaluated with the Kolmogorov-Smirnov test. Any correlations between the variables under evaluation will be assessed by Spearman r correlation. To compare qualitative data will be used the Chi-square test.

Discussion: The main strengths of the SCARIS study are the following: it's the first large RCT on schizophrenic patient, involving in and outpatient, evaluating the effect of a three-arm study design, and a long term of follow-up (52-weeks).The goal is to propose an effective intervention to reduce the risk of tobacco smoking, as a complementary tool to treat tobacco addiction in schizophrenia.

Trial registration: ClinicalTrials.gov, NCT01979796.

Figure 1

Electronic cigarette. It is a disposable model that closely resembles the shape of a tobacco cigarette, with a rechargeable 3.7-V, 120mAh, lithium-ion battery. The electronic cigarette contains a liquid solution of vegetable glycerin in which nicotine or an aroma is dissolved.

Figure 2

The PAIPO nicotine-free inhalator (EchosSrl, Milan, Italy). It is a plastic device that resembles a cigarette and is intended to replace some of the rituals associated with smoking gestures. The plastic device contains a sponge filter soaked in natural oil enriched with extracts of different aromas.

Figure 3

Study design. The study is a three-arm, randomized controlled, clinical trial designed to assess the efficacy and safety of the e-cigarette with 24 mg nicotine, the e-cigarette with no (0 mg) nicotine and the PAIPO nicotine-free inhalator.