www.medscape.com
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[h=2]Authors and Disclosures[/h]Riccardo Polosa1,2*, Pasquale Caponnetto1,2, Jaymin B Morjaria3, Gabriella Papale1,2, Davide Campagna1,2 and Cristina Russo1,2
1Centro per la Prevenzione e Cura del Tabagismo (CPCT), Azienda Ospedaliero-Universitaria "Policlinico-Vittorio Emanuele", Università di Catania, Catania, Italy. 2Institute of Internal Medicine, S. Marta Hospital, Azienda Ospedaliero-Universitaria "Policlinico-Vittorio Emanuele", Università di Catania, Catania, Italy. 3IIR Division, School of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
*Correspondence
polosa@unict.it
[h=2]From BMC Public Health[/h][h=1]Effect of an Electronic Nicotine Delivery device (e-Cigarette) on Smoking Reduction and Cessation[/h][h=4]A Prospective 6-month Pilot Study[/h]Riccardo Polosa; Pasquale Caponnetto; Jaymin B Morjaria; Davide Campagna; Cristina Russo
Posted: 12/28/2011; BMC Public Health. 2011;11(786) © 2011 BioMed Central, Ltd.
[h=3]Abstract and Introduction[/h][h=4]Abstract[/h]Background: Cigarette smoking is a tough addiction to break. Therefore, improved approaches to smoking cessation are necessary. The electronic-cigarette (e-Cigarette), a battery-powered electronic nicotine delivery device (ENDD) resembling a cigarette, may help smokers to remain abstinent during their quit attempt or to reduce cigarette consumption. Efficacy and safety of these devices in long-term smoking cessation and/or smoking reduction studies have never been investigated.
Methods: In this prospective proof-of-concept study we monitored possible modifications in smoking habits of 40 regular smokers (unwilling to quit) experimenting the 'Categoria' e-Cigarette with a focus on smoking reduction and smoking abstinence. Study participants were invited to attend a total of five study visits: at baseline, week-4, week-8, week-12 and week-24. Product use, number of cigarettes smoked, and exhaled carbon monoxide (eCO) levels were measured at each visit. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed.
Results: Sustained 50% reduction in the number of cig/day at week-24 was shown in 13/40(32.5%) participants; their median of 25 cigs/day decreasing to 6 cigs/day (p < 0.001). Sustained 80% reduction was shown in 5/40(12.5%) participants; their median of 30 cigs/day decreasing to 3 cigs/day (p = 0.043). Sustained smoking abstinence at week-24 was observed in 9/40(22.5%) participants, with 6/9 still using the e-Cigarette by the end of the study. Combined sustained 50% reduction and smoking abstinence was shown in 22/40 (55%) participants, with an overall 88% fall in cigs/day. Mouth (20.6%) and throat (32.4%) irritation, and dry cough (32.4%) were common, but diminished substantially by week-24. Overall, 2 to 3 cartridges/day were used throughout the study. Participants' perception and acceptance of the product was good.
Conclusion: The use of e-Cigarette substantially decreased cigarette consumption without causing significant side effects in smokers not intending to quit (http://ClinicalTrials.gov number NCT01195597).
[h=3]Background[/h]With well over one billion smokers' worldwide, cigarette smoking is a global epidemic that poses a substantial health burden and costs.[1] This is because cigarette smoke harms several organ systems of the human body, thus causing a broad range of diseases, many of which are fatal.[2,3] The risk of serious disease diminishes rapidly after quitting and life-long abstinence is known to reduce the risk of lung cancer, heart disease, strokes, chronic lung disease and other cancers.[4,5]
Although evidence-based recommendations indicate that smoking cessation programs are useful in helping smokers to quit,[6] smoking is a very difficult addiction to break. It has been shown that approximately 80% of smokers who attempt to quit on their own, relapse within the first month of abstinence and only about 35% remain abstinent at 6 months.[7] Although there is little doubt that currently-marketed smoking cessation products increase the chance of committed smokers to stop smoking, they reportedly lack high levels of efficacy, especially in the real life setting.[8] Although this is known to reflect the chronic relapsing nature of tobacco dependence, the need for novel and effective approaches to smoking cessation interventions is beyond doubt.
The electronic-cigarette (e-Cigarette) is a battery-powered electronic nicotine delivery device (ENDD) resembling a cigarette designed for the purpose of nicotine delivery,where no tobacco or combustion is necessary for its operation[9] (Figure 1). Consequently, this product may be considered as a lower risk substitute for factory-made cigarettes. In addition, people report buying them to help quit smoking, to reduce cigarette consumption and to relieve tobacco withdrawal symptoms due to workplace smoking restrictions.[10] Besides delivering nicotine, e-Cigarettes may also provide a coping mechanism for conditioned smoking cues by replacing some of the rituals associated with smoking gestures (e.g. hand-to-mouth action of smoking). For this reason, e-Cigarettes may help smokers to remain abstinent during their quit attempt or to reduce cigarette consumption. A recent internet survey on the satisfaction of e-Cigarette use has reported that the device helped in smoking abstinence and improved smoking-related symptoms.[11] Under acute experimental conditions, two marketed electronic cigarette brands suppressed tobacco abstinence symptom ratings without leading to measurable levels of nicotine or CO in the exhaled breath.[12] The e-Cigarette is a very hot topic that has generated considerable global debate with authorities wanting to ban it or at least regulate it. Consequently, a formal demonstration supporting the efficacy and safety of these devices in smoking cessation and/or smoking reduction studies would be of utmost importance.
[h=3]Methods[/h][h=4]Participants[/h]Healthy smokers 1860 years old, smoking ≥ 15 factory-made cigarettes per day (cig/day) for at least the past 10 years and not currently attempting to quit smoking or wishing to do so in the next 30 days were recruited from the local Hospital staff in Catania, Italy. None of the participants reported a history of alcohol and illicit drug use, major depression or other psychiatric conditions. We also excluded subjects who reported recent myocardial infarction, angina pectoris, high blood pressure (BP > 140 mmHg systolic and/or 90 mmHg diastolic), diabetes mellitus, severe allergies, poorly controlled asthma or other airways diseases. The study protocol was discussed with the Chair of the local institutional ERB (Comitato Etico Azienda Vittorio Emanuele) in February 2010. In consideration of the fact that e-cigarette use is a widespread phenomenon in Italy, that many e-cigarette users are enjoying them as consumer goods, that this type of product is not regulated as a drug or a drug device in Italy (end users can buy e-cig almost anywhere - internet, tobacconists, pharmacies, restaurants, and shops), and that only healthy smokers not willing to quit smoking would participate, it was felt that the study fulfilled the criteria of an observational naturalistic investigation and was exempt from the requirement from ethical approval. Participants gave written informed consent prior to participation in the study.
[h=4]Study Design and Baseline Measures[/h]Eligible participants were invited to use an ENDD ('Categoria' e-Cigarette, Arbi Group Srl, Milano, Italy) and were followed up prospectively for 6 months. They attended a total of five study visits at our smoking cessation clinic (Centro per la Prevenzione e Cura del Tabagismo (CPCT), Università di Catania, Italy): a baseline visit and four follow-up visits, (at week-4, week-8, week-12 and week-24) (Figure 2).
Participants were permitted to use the study product ad libitum throughout the day (up to a maximum of 4 cartridges per day, as recommended by the manufacturer) in the anticipation of reducing the number of cig/day smoked, and to fill a 4-weeks' study diary recording product use, number of any tobacco cigarettes smoked, and adverse events.
Participants were invited to came back at week-4 (study visit 2), week-8 (study visit 3), and week-12 (visit 4), a) to receive further free supply of nicotine cartridges together with the study diaries for the residual study periods, b) to record their eCO levels, and c) to give back completed study diaries and unused study products.
Study participants attended a final follow-up visit at week-24 (study visit 5) to report product use (cartridges/day) and the number of any tobacco cigarettes smoked (from which smoking reduction and smoking abstinence could be calculated), to re-check eCO levels and to rate the degree of usefulness of the study product. In particular, participants were asked to rate their level of satisfaction with the products compared to their usual cigarettes using a visual analogue scale (VAS) from 0 to 10 points (0 = being 'completely unsatisfied', 10 being = 'fully satisfied'); on the same scale, they also rated helpfulness (in keeping them from smoking) and whether they would recommend it to a friend who wanted to stop/reduce smoking. Adverse events were obtained from their study diaries.
Given the observational nature of this study, no emphasis on encouragement, motivation and reward for the smoking cessation effort were provided since this study was intended to monitor the case of a smoker (unwilling to quit) trying out an unconventional nicotine delivery device in a real world setting. Although participants were allowed to smoke their own brand of cigarette as they wished, smoking cessation services were provided to those who would spontaneously ask for assistance with quitting. These subjects were excluded from the study protocol.
[h=4]Study Outcome Measures[/h]The primary efficacy measure was sustained 50% reduction in the number of cig/day at week-24 from baseline ( reducers );[15] defined as sustained self-reported 50% reduction in the number of cig/day compared to baseline for the 30 days period prior to week-24 study visit (eCO levels were measured to verify smoking status and confirm a reduction compared to baseline).
A secondary efficacy measure of the study was sustained 80% reduction in the number of cig/day at week-24 from baseline ( heavy reducers ); defined as sustained self-reported 80% reduction in the number of cig/day compared to baseline for the 30 days period prior to week-24 study visit (eCO levels were measured to verify smoking status and confirm a reduction compared to baseline).
An additional secondary efficacy measure of the study was sustained smoking abstinence at week-24 ( quitters ); defined as complete self-reported abstinence from tobacco smoking (not even a puff) for the 30 days period prior to week-24 study visit (eCO levels were measured to objectively verify smoking status with an eCO concentration of ≤10 ppm).
Those smokers who failed to meet the above criteria at the final week-24 follow-up visit (study visit 5) were categorized as reduction/cessation failures ( failures ).
[h=4]Statistical Analyses[/h]This was a proof-of-concept pilot study, the first of its kind, hence no previous data could be used for power calculation. However, using our previous experience in smoking cessation studies, we estimated that a sample of 40 subjects would have been adequate to acquire quit/reduction rates from 70-75% of the subjects enrolled.[16] Primary and secondary outcome measures were computed by including all enrolled participants - assuming that all those individuals who were lost to follow-up are classified as failures (intention-to-treat analysis). The changes from baseline (study visit 1) in number of cig/day and in eCO levels were compared with data recorded at subsequent follow-up visits using Wilcoxon Signed rank test as these data were non-parametric. Parametric and non-parametric data were expressed as mean (± SD) and median (interquartile range (IQR)) respectively. Correlations were calculated using Spearman's Rho Correlation. Statistical methods were 2-tailed, and P values of < 0.05 were considered significant.
[h=3]Results[/h][h=4]Participant Characteristics[/h]After excluding for the study exclusion criteria, a total of 40 (M 26; F 14; mean (± SD) age of 42.9 (± 8.8) years) regular smokers (mean (± SD) pack/yrs of 34.9 (± 14.7)) consented to participate and were included in the study (Table 1; Figure 2). Twenty-seven (67.5%) completed all study visits and returned for their final follow-up visit at week-24. Baseline characteristics of those who were lost to follow-up were not significantly different from participants who completed the study.
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[h=4]Table 1. Patient Demographics[/h]
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[h=2]Authors and Disclosures[/h]Riccardo Polosa1,2*, Pasquale Caponnetto1,2, Jaymin B Morjaria3, Gabriella Papale1,2, Davide Campagna1,2 and Cristina Russo1,2
1Centro per la Prevenzione e Cura del Tabagismo (CPCT), Azienda Ospedaliero-Universitaria "Policlinico-Vittorio Emanuele", Università di Catania, Catania, Italy. 2Institute of Internal Medicine, S. Marta Hospital, Azienda Ospedaliero-Universitaria "Policlinico-Vittorio Emanuele", Università di Catania, Catania, Italy. 3IIR Division, School of Medicine, University of Southampton, Southampton General Hospital, Southampton SO16 6YD, UK
*Correspondence
polosa@unict.it
[h=2]From BMC Public Health[/h][h=1]Effect of an Electronic Nicotine Delivery device (e-Cigarette) on Smoking Reduction and Cessation[/h][h=4]A Prospective 6-month Pilot Study[/h]Riccardo Polosa; Pasquale Caponnetto; Jaymin B Morjaria; Davide Campagna; Cristina Russo
Posted: 12/28/2011; BMC Public Health. 2011;11(786) © 2011 BioMed Central, Ltd.
[h=3]Abstract and Introduction[/h][h=4]Abstract[/h]Background: Cigarette smoking is a tough addiction to break. Therefore, improved approaches to smoking cessation are necessary. The electronic-cigarette (e-Cigarette), a battery-powered electronic nicotine delivery device (ENDD) resembling a cigarette, may help smokers to remain abstinent during their quit attempt or to reduce cigarette consumption. Efficacy and safety of these devices in long-term smoking cessation and/or smoking reduction studies have never been investigated.
Methods: In this prospective proof-of-concept study we monitored possible modifications in smoking habits of 40 regular smokers (unwilling to quit) experimenting the 'Categoria' e-Cigarette with a focus on smoking reduction and smoking abstinence. Study participants were invited to attend a total of five study visits: at baseline, week-4, week-8, week-12 and week-24. Product use, number of cigarettes smoked, and exhaled carbon monoxide (eCO) levels were measured at each visit. Smoking reduction and abstinence rates were calculated. Adverse events and product preferences were also reviewed.
Results: Sustained 50% reduction in the number of cig/day at week-24 was shown in 13/40(32.5%) participants; their median of 25 cigs/day decreasing to 6 cigs/day (p < 0.001). Sustained 80% reduction was shown in 5/40(12.5%) participants; their median of 30 cigs/day decreasing to 3 cigs/day (p = 0.043). Sustained smoking abstinence at week-24 was observed in 9/40(22.5%) participants, with 6/9 still using the e-Cigarette by the end of the study. Combined sustained 50% reduction and smoking abstinence was shown in 22/40 (55%) participants, with an overall 88% fall in cigs/day. Mouth (20.6%) and throat (32.4%) irritation, and dry cough (32.4%) were common, but diminished substantially by week-24. Overall, 2 to 3 cartridges/day were used throughout the study. Participants' perception and acceptance of the product was good.
Conclusion: The use of e-Cigarette substantially decreased cigarette consumption without causing significant side effects in smokers not intending to quit (http://ClinicalTrials.gov number NCT01195597).
[h=3]Background[/h]With well over one billion smokers' worldwide, cigarette smoking is a global epidemic that poses a substantial health burden and costs.[1] This is because cigarette smoke harms several organ systems of the human body, thus causing a broad range of diseases, many of which are fatal.[2,3] The risk of serious disease diminishes rapidly after quitting and life-long abstinence is known to reduce the risk of lung cancer, heart disease, strokes, chronic lung disease and other cancers.[4,5]
Although evidence-based recommendations indicate that smoking cessation programs are useful in helping smokers to quit,[6] smoking is a very difficult addiction to break. It has been shown that approximately 80% of smokers who attempt to quit on their own, relapse within the first month of abstinence and only about 35% remain abstinent at 6 months.[7] Although there is little doubt that currently-marketed smoking cessation products increase the chance of committed smokers to stop smoking, they reportedly lack high levels of efficacy, especially in the real life setting.[8] Although this is known to reflect the chronic relapsing nature of tobacco dependence, the need for novel and effective approaches to smoking cessation interventions is beyond doubt.
The electronic-cigarette (e-Cigarette) is a battery-powered electronic nicotine delivery device (ENDD) resembling a cigarette designed for the purpose of nicotine delivery,where no tobacco or combustion is necessary for its operation[9] (Figure 1). Consequently, this product may be considered as a lower risk substitute for factory-made cigarettes. In addition, people report buying them to help quit smoking, to reduce cigarette consumption and to relieve tobacco withdrawal symptoms due to workplace smoking restrictions.[10] Besides delivering nicotine, e-Cigarettes may also provide a coping mechanism for conditioned smoking cues by replacing some of the rituals associated with smoking gestures (e.g. hand-to-mouth action of smoking). For this reason, e-Cigarettes may help smokers to remain abstinent during their quit attempt or to reduce cigarette consumption. A recent internet survey on the satisfaction of e-Cigarette use has reported that the device helped in smoking abstinence and improved smoking-related symptoms.[11] Under acute experimental conditions, two marketed electronic cigarette brands suppressed tobacco abstinence symptom ratings without leading to measurable levels of nicotine or CO in the exhaled breath.[12] The e-Cigarette is a very hot topic that has generated considerable global debate with authorities wanting to ban it or at least regulate it. Consequently, a formal demonstration supporting the efficacy and safety of these devices in smoking cessation and/or smoking reduction studies would be of utmost importance.
Figure 1. Structure of the 'Categoria' electronic-cigarette (e-Cigarette). The e-Cigarette is a battery-powered electronic nicotine delivery device (ENDD) resembling a cigarette designed for the purpose of providing inhaled doses of nicotine by way of a vaporized solution to the respiratory system. This device provides a flavor and physical sensation similar to that of inhaled tobacco smoke, while no smoke or combustion is actually involved in its operation. It is composed of the following key components: (1) the inhaler - also known as 'cartridge' (a disposable non-refillable plastic mouthpiece - resembling a tobacco cigarette's filter - which contains an absorbent material that is saturated with a liquid solution containing nicotine); (2) the atomizing device (the heating element that vaporizes the liquid in the mouthpiece and generates the mist with each puff); (3) the battery component (the body of the device - resembling a tobacco cigarette - which houses a lithium-ion re-chargeable battery to power the atomizer). The body of the device also houses an electronic airflow sensor to automatically activate the heating element upon inhalation and to light up a red LED indicator to signal activation of the device with each puff. Each pre-filled 'Original' cartridges used in this study contains nicotine (7.25 mg/cartridge) dissolved in propylene glycol (233.7 mg/cartridge) and vegetable glycerin (64.0 mg/cartridge) [details can be found at: http://www.liaf-onlus.org/public/allegati/categoria1b.pdf].
With this in mind, we designed a prospective proof-of-concept study to monitor possible modifications in the smoking habits of a group of well characterized regular smokers experimenting the most popular marketed e-Cigarette in Italy ('Categoria'; Arbi Group Srl, Milano, Italy) focusing on smoking reduction and smoking abstinence. We also monitored adverse events and measured participants' perception and acceptance of the product.[h=3]Methods[/h][h=4]Participants[/h]Healthy smokers 1860 years old, smoking ≥ 15 factory-made cigarettes per day (cig/day) for at least the past 10 years and not currently attempting to quit smoking or wishing to do so in the next 30 days were recruited from the local Hospital staff in Catania, Italy. None of the participants reported a history of alcohol and illicit drug use, major depression or other psychiatric conditions. We also excluded subjects who reported recent myocardial infarction, angina pectoris, high blood pressure (BP > 140 mmHg systolic and/or 90 mmHg diastolic), diabetes mellitus, severe allergies, poorly controlled asthma or other airways diseases. The study protocol was discussed with the Chair of the local institutional ERB (Comitato Etico Azienda Vittorio Emanuele) in February 2010. In consideration of the fact that e-cigarette use is a widespread phenomenon in Italy, that many e-cigarette users are enjoying them as consumer goods, that this type of product is not regulated as a drug or a drug device in Italy (end users can buy e-cig almost anywhere - internet, tobacconists, pharmacies, restaurants, and shops), and that only healthy smokers not willing to quit smoking would participate, it was felt that the study fulfilled the criteria of an observational naturalistic investigation and was exempt from the requirement from ethical approval. Participants gave written informed consent prior to participation in the study.
[h=4]Study Design and Baseline Measures[/h]Eligible participants were invited to use an ENDD ('Categoria' e-Cigarette, Arbi Group Srl, Milano, Italy) and were followed up prospectively for 6 months. They attended a total of five study visits at our smoking cessation clinic (Centro per la Prevenzione e Cura del Tabagismo (CPCT), Università di Catania, Italy): a baseline visit and four follow-up visits, (at week-4, week-8, week-12 and week-24) (Figure 2).
Figure 2. Number of patients recruited and flow of patients within the study. A total of 66 subjects with specifically predefined smoking criteria (smoking ≥ 15 cig/day for at least the past 10 years) responded to the advert; of these, 14 subjects were not included in the study because they spontaneously seek assistance with quitting (these were then invited to attend the local smoking cessation clinic, which offers standard support with cessation counselling and pharmacotherapy for nicotine dependence). The remaining 52 subjects consented to participate into the study; of these, 12 were not considered eligible because of the exclusion criteria (6 had a high blood pressure, 2 were older than 60; 2 had a diagnosis of major depression; 1 suffered from recent myocardial infarction; 1 had uncontrolled allergic asthma). In the end, 40 volunteers were included in the study and were issued with e-Cigarette kits loaded with nicotine cartridges. By the end of the study, a total of 13 subjects were lost to follow-up due to failure of attending their control visits. Overall 27 participants were available for analyses at the 24-week follow-up visit.
At baseline (study visit 1), basic demographic and a detailed smoking history were taken and individual pack-years (pack/yrs) calculated together with scoring of their level of nicotine dependence by means of Fagerstrom Test of Nicotine Dependence (FTND) questionnaire.[13] Subjective ratings of depression were assessed with the Beck Depression Inventory (BDI).[14] Additionally, levels of carbon monoxide in exhaled breath (eCO) were measured using a portable device (Micro CO, Micro Medical Ltd, UK). Participants were given a free e-Cigarette kit containing two rechargeable batteries, a charger, and two atomizers and instructed on how to charge, activate and use the e-Cigarette. Key troubleshooting were addressed and phone numbers were supplied for both technical and medical assistance. A full 4-weeks supply of 7.4 mg nicotine cartridges ("Original" cartridges; Arbi Group Srl, Milano, Italy) was also provided and participants were trained on how to load them onto the e-Cigarette's atomizer. Random checks confirmed that the nicotine content per cartridge was 7,25 mg. Detailed toxicology and nicotine content analyses of "Original" cartridges had been carried in a laboratory certified by the Italian Institute of Health and can be found at: http://www.liaf-onlus.org/public/allegati/categoria1b.pdf Participants were permitted to use the study product ad libitum throughout the day (up to a maximum of 4 cartridges per day, as recommended by the manufacturer) in the anticipation of reducing the number of cig/day smoked, and to fill a 4-weeks' study diary recording product use, number of any tobacco cigarettes smoked, and adverse events.
Participants were invited to came back at week-4 (study visit 2), week-8 (study visit 3), and week-12 (visit 4), a) to receive further free supply of nicotine cartridges together with the study diaries for the residual study periods, b) to record their eCO levels, and c) to give back completed study diaries and unused study products.
Study participants attended a final follow-up visit at week-24 (study visit 5) to report product use (cartridges/day) and the number of any tobacco cigarettes smoked (from which smoking reduction and smoking abstinence could be calculated), to re-check eCO levels and to rate the degree of usefulness of the study product. In particular, participants were asked to rate their level of satisfaction with the products compared to their usual cigarettes using a visual analogue scale (VAS) from 0 to 10 points (0 = being 'completely unsatisfied', 10 being = 'fully satisfied'); on the same scale, they also rated helpfulness (in keeping them from smoking) and whether they would recommend it to a friend who wanted to stop/reduce smoking. Adverse events were obtained from their study diaries.
Given the observational nature of this study, no emphasis on encouragement, motivation and reward for the smoking cessation effort were provided since this study was intended to monitor the case of a smoker (unwilling to quit) trying out an unconventional nicotine delivery device in a real world setting. Although participants were allowed to smoke their own brand of cigarette as they wished, smoking cessation services were provided to those who would spontaneously ask for assistance with quitting. These subjects were excluded from the study protocol.
[h=4]Study Outcome Measures[/h]The primary efficacy measure was sustained 50% reduction in the number of cig/day at week-24 from baseline ( reducers );[15] defined as sustained self-reported 50% reduction in the number of cig/day compared to baseline for the 30 days period prior to week-24 study visit (eCO levels were measured to verify smoking status and confirm a reduction compared to baseline).
A secondary efficacy measure of the study was sustained 80% reduction in the number of cig/day at week-24 from baseline ( heavy reducers ); defined as sustained self-reported 80% reduction in the number of cig/day compared to baseline for the 30 days period prior to week-24 study visit (eCO levels were measured to verify smoking status and confirm a reduction compared to baseline).
An additional secondary efficacy measure of the study was sustained smoking abstinence at week-24 ( quitters ); defined as complete self-reported abstinence from tobacco smoking (not even a puff) for the 30 days period prior to week-24 study visit (eCO levels were measured to objectively verify smoking status with an eCO concentration of ≤10 ppm).
Those smokers who failed to meet the above criteria at the final week-24 follow-up visit (study visit 5) were categorized as reduction/cessation failures ( failures ).
[h=4]Statistical Analyses[/h]This was a proof-of-concept pilot study, the first of its kind, hence no previous data could be used for power calculation. However, using our previous experience in smoking cessation studies, we estimated that a sample of 40 subjects would have been adequate to acquire quit/reduction rates from 70-75% of the subjects enrolled.[16] Primary and secondary outcome measures were computed by including all enrolled participants - assuming that all those individuals who were lost to follow-up are classified as failures (intention-to-treat analysis). The changes from baseline (study visit 1) in number of cig/day and in eCO levels were compared with data recorded at subsequent follow-up visits using Wilcoxon Signed rank test as these data were non-parametric. Parametric and non-parametric data were expressed as mean (± SD) and median (interquartile range (IQR)) respectively. Correlations were calculated using Spearman's Rho Correlation. Statistical methods were 2-tailed, and P values of < 0.05 were considered significant.
[h=3]Results[/h][h=4]Participant Characteristics[/h]After excluding for the study exclusion criteria, a total of 40 (M 26; F 14; mean (± SD) age of 42.9 (± 8.8) years) regular smokers (mean (± SD) pack/yrs of 34.9 (± 14.7)) consented to participate and were included in the study (Table 1; Figure 2). Twenty-seven (67.5%) completed all study visits and returned for their final follow-up visit at week-24. Baseline characteristics of those who were lost to follow-up were not significantly different from participants who completed the study.
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[h=4]Table 1. Patient Demographics[/h]