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Multicentric cohort study on the long-term efficacy and safety of electronic cigarettes: study design and methodology

Lamberto Manzoli1*, Carlo La Vecchia23, Maria Elena Flacco1, Lorenzo Capasso1, Valentina Simonetti4, Stefania Boccia5, Angela Di Baldassarre1, Paolo Villari6, Andrea Mezzetti7 and Giancarlo Cicolini4

Author Affiliations

1 Department of Medicine and Aging Sciences, University of Chieti, via dei Vestini 5, 66013 Chieti, Italy

2 IRCCS Istituto di Ricerche Farmacologiche “Mario Negri”, Via la Masa 19 20156 Milan, Italy

3 Department of Clinical Sciences and Community Health, University of Milan, Via Commenda 9/12, 20156 Milan, Italy

4 Local Health Authority of Lanciano-Vasto-Chieti, Via Martiri Lancianesi, 66100 Chieti, Italy

5 University “Catholic of the Sacred Heart” of Rome, Largo Francesco Vito, 1-00168 Rome, Italy

6 University Sapienza of Rome, Viale Regina Elena 324, 00161 Rome, Italy

7 Clinical Research Center, Ce.S.I., University “G. d‘Annunzio” Foundation, Via Colle dell‘Ara, 66013 Chieti, Italy

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BMC Public Health 2013, 13:883  doi:10.1186/1471-2458-13-883

Published: 24 September 2013



While electronic cigarettes are forbidden in several countries, their sales are exploding in many others. Although e-cigarettes have been proposed as long-term substitutes for traditional smoking or as a tool for smoking cessation, very scarce data are available on their efficacy and safety.

We describe the protocol of a 5-year multicentric prospective study aimed to evaluate short- and long-term adherence to e-cigarette smoking and the efficacy of e-cigarettes in reducing and/or quitting traditional cigarette smoking. The study will also compare the health effects of electronic vs traditional vs mixed cigarette smoking.


From June to December 2013, we will enroll adult smokers of: (EC) e-cigarettes (self-reported inhaling ≥ 50 puffs per week since ≥ 6 months); (TC) traditional cigarettes (≥ 1 per day since ≥ 6 m); (Mixed) both electronic and traditional cigarettes (≥1 per day since ≥ 6 m). Eligible subjects will be requested participation through newspaper advertisements and direct contact at the shops. Each subject will have to compile a structured questionnaire at enrolment and after 6, 12, 24, 36 and 60 months. The level of carbon monoxide in expired after breath will be evaluated in all subjects declaring no traditional cigarette smoking in any follow-up phase, using portable carbon monoxide analyzers. The primary outcomes are traditional smoking cessation rates and number of smoked cigarettes. Secondary outcomes include adherence to e-cigarettes, self-reported adverse events, quality of life, and time to hospital admission for one among cardiovascular diseases, chronic obstructive pulmonary diseases, cancer of the lung, esophagus, larynx, oral cavity, bladder, pancreas, kidney, stomach, cervix, and myeloid leukemia. Admissions will be checked using official discharge data of the Abruzzo Region. A minimum of 500 subjects in each group will be enrolled, for a total of 1500 participants. Cox proportional hazards analysis will be used to calculate adjusted relative hazards of smoking cessation by each variable.


Data on long-term efficacy and safety of e-cigarettes will be of utmost importance to form the basis for guidelines and regulatory decisions on e-cigarettes.

Trial registration

The protocol has been registered (NCT01785537) and approved by the Ethics Committee of the University of Chieti (Record n. 6; 25-03-2013).

Electronic cigarette; Cigarette smoking; Efficacy; Safety; Cohort study; Italy