Czoli 2019.
| Study characteristics | ||
| Methods | Design: Nonblinded within‐participants cross‐over Recruitment: advertisements placed in newspapers, online, and in local vape shops, and received CAD 295 for participating in the study Setting: Kitchener−Waterloo and Toronto, Ontario, Canada Study start date: September 2015. Study end date: NR |
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| Participants | Total N: 48 29.2% female; mean age 35.9 (SD 11.7); mean cpd NR; dual EC users at baseline; not motivated to quit Inclusion criteria: > 18+ years; dual users of tobacco cigarettes and EC. Exclusion criteria: serious intentions to quit smoking in the next 6 months; tobacco products, NRT, any smoking cessation medications, participation counselling programs for smoking cessation in the past 7 days; serious cardiac health issues; heart attack or stroke within the last 3 months; cancer within the last year; asthma, chronic obstructive pulmonary disease, a seizure disorder, or any life‐threatening medical conditions with a prognosis of ≤ a year; history of psychosis, schizophrenia, bipolar disorder, or suicidal thoughts. |
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| Interventions |
EC: own choice (mainly tank) 3 consecutive 7‐day periods in which the use of tobacco cigarettes and e‐cigarettes was experimentally manipulated 4 study conditions: Dual use (e‐cigarette and tobacco cigarette); Tobacco cigarette; E‐cigarette; No product use Virtually all dual users reported using tank systems (92%) and e‐cigarettes with nicotine (94%) To control for order effects, participants were randomly assigned to 1 of 2 condition orders, A or B Following the baseline condition of dual use: Group A participants switched to E‐cigarette use, then to Tobacco cigarette use, and finally to No product use Group B participants switched to Tobacco cigarette use, then to E‐cigarette use, and finally to No product use |
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| Outcomes | Baseline (visit 1) and after each of the 7‐day periods (visit 2 (week 1), visit 3 (week 2), visit 4 (week 3)) Carbon monoxide Urinary concentration of cotinine Urinary concentrations of 1‐hydroxypyrene (1‐HOP) and 4‐(methylnitrosamino)‐1‐(3‐pyridyl)‐1‐butanol (NNAL) |
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| Study funding | This research was supported by an Ontario Ministry of Health and LongTerm Care Health System Research Fund grant (#06697 awarded to DH). Additional support was provided by the Canadian Institutes of Health Research (CIHR), the Vanier Canada Graduate Scholarship (CDC), a CIHR and Public Health Agency of Canada, Applied Public Health Chair (DH), and an Ontario Institute for Cancer Research Investigator Award (GTF) | |
| Author declarations | MLG reports grants from and served as an advisory board member to pharmaceutical companies that manufacture smoking cessation drugs. DH has provided paid expert testimony in tobacco litigation on behalf of governments and class‐action plaintiffs on issues related to tobacco product science and regulation. The other authors have no competing interests to declare | |
| Notes | ||
| Risk of bias | ||
| Bias | Authors' judgement | Support for judgement |
| Random sequence generation (selection bias) | Unclear risk | No details of randomization method given |
| Allocation concealment (selection bias) | High risk | No blinding |
| Blinding of participants and personnel (performance bias) All outcomes | High risk | No blinding |
| Blinding of outcome assessment (detection bias) All outcomes | Unclear risk | Not reported |
| Incomplete outcome data (attrition bias) All outcomes | Low risk | All followed up |
| Selective reporting (reporting bias) | Low risk | No evidence of selective reporting |