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. 2021 Apr 29;2021(4):CD010216. doi: 10.1002/14651858.CD010216.pub5

Carpenter 2017.

Study characteristics
Methods Design: Randomized parallel‐assignment open‐label trial
Recruitment: Recruitment from local urban community in southeastern USA, using various media outlets
Setting: Community, southeastern USA
Study start date: November 2014; Study end date: May 2016
Participants Total N: 68
N per arm: Control group: 22; ENDS group: 46 (split into 2 non‐randomized groups: BluCig 16 mg: 25; BluCig 24 mg: 21)
Inclusion criteria:

  • Age 18+

  • Current smoker of ≥ 5 cpd for ≥ 1 year

  • No recent history of cardiovascular distress, COPD, cancer (any non‐dermatologic), or uncontrolled diabetes mellitus

  • Neither pregnant nor breastfeeding (verified)

  • Absence of any major current psychiatric impairment, including current alcohol/drug abuse/dependence

  • Current, active use of email

  • At least some concern for health effects of smoking (> none at all on a Likert scale)

  • Not used any ENDS product in the past 6 months

  • Never purchased an ENDS product


Exclusion criteria:

  • Use of non‐cigarette tobacco products (e.g. cigarillos) in the last 30 days

  • Current use of any smoking cessation medications

  • Current enrolment in a smoking cessation treatment study


Women: 59.7%; Mean age: 42.2; Mean cpd: 15.3; Heaviness of smoking (0 ‐ 6): 2.9
EC use: Control: 9%; ENDS 16 mg group: 4%; ENDS 24mg group: 33%
Motivation to quit smoking in next month (0 – 10): Control: 4.0; ENDS 16 mg: 5.0; ENDS 24 mg: 4.4
Interventions EC: Cig‐a‐like
Intervention: At study start, choice of tobacco or menthol flavor Blu Starter Pack EC, with 16 mg/mL nicotine. Midway through study, the manufacturer of Blu altered the product and discontinued availability of the device, replaced with BluPlusþ, with 24 mg/mL nicotine. 3‐week sampling period, given up to 7 cartridges at each of 3 weekly visits. Instructions on usage "kept minimal to preserve naturalistic intent." The study team suggested that ENDS could be used "as you wish, to cut down or quit smoking, help manage smoking restrictions, or both."
Control: own brand of cigarettes
Outcomes Weeks 2, 3, 4, 8, 12 and 16
Carbon monoxide, NNAL
Other outcomes: cessation (< 6 months), product evaluation, EMA
Study funding "Support was provided by NIH R21 DA037407 (to M.J. Carpenter), P01 CA200512 (to K.M. Cummings, M.J. Carpenter, and M.L. Goniewicz), UL1 TR001450, and P30 CA138313. M.L. Goniewicz's laboratory is supported via P30 CA016056. B.W. Heckman is supported via K12 DA031794 and K23 DA041616. T.L. Wagener's effort is partially supported by the Oklahoma Tobacco Research Center, which is funded by the Oklahoma Tobacco Settlement Endowment Trust."
Author declarations "M.L. Goniewicz is a consultant/advisory board member for Johnson & Johnson. K.M. Cummings reports receiving a commercial research grant from and is a consultant/advisory board member for Pfizer Inc., and has provided expert witness testimony for various plaintiffs in lawsuits involving cigarette manufacturers. No potential conflicts of interest were disclosed by the other authors."
Notes New for 2020 update. Listed as ongoing study NCT02357173 in 2016 review update. Additional data provided from authors
In all, 25 participants (54%) received the Blu Starter Pack (16 mg), and 21 participants (46%) received BluPlusþ (24 mg); no switches were made within participants. Note: this is not included in our analysis of higher v lower as assignment to nicotine dose was not done at random; 24 mg and 16 mg merged in our main analysis
Risk of bias
Bias Authors' judgement Support for judgement
Random sequence generation (selection bias) Unclear risk Quote: “Randomization to group was stratified by motivation to quit in the next 30 days (0–6 vs. 7–10 on a VAS scale) but proportioned 2:1 (ENDS:control) to increase precision estimates for e‐cigarette uptake and usage.”
Allocation concealment (selection bias) Unclear risk Not specified
Blinding of participants and personnel (performance bias)
All outcomes High risk Not blinded and includes non‐active control
Blinding of outcome assessment (detection bias)
All outcomes High risk CO biochemically verified but abstinence not used as outcome in this review, so rated based on adverse event reporting. Self‐report, no blinding of participants.
Incomplete outcome data (attrition bias)
All outcomes Low risk Retention rate:
Week 4: Control:19/22 (86%); ENDS 16 mg: 23/25 (92%); ENDS 24 mg: 20/21 (95%)
Week 16: Control: 16/22 (73%); ENDS 16 mg: 19/25 (76%); ENDS 24 mg: 15/21 (71%)
Selective reporting (reporting bias) Unclear risk Not specified
Other bias Low risk Midway through the study, the manufacturer of Blu altered the product and discontinued availability of the device, replaced with BluPlusþ, with 24 mg/mL nicotine, again offered in both tobacco and menthol flavorings, and with improved battery duration (4‐watt battery for both devices). In all, 25 participants (54%) received the Blu Starter Pack (16 mg), and 21 participants (46%) received BluPlusþ (24 mg); no switches were made within participants. The change in product (IRB approved) allowed us the unexpected opportunity to assess what impact, if any, the change in product design had on study outcomes. Note that the manufacturer, style of device, and packaging did not change, nor did our messaging to participants. The only difference was the strength of product. Thus, trial outcomes are reported across 3 groups: control versus 16 mg versus 24 mg ENDS. We have not rated this as high risk of bias as our analyses do not compare on nicotine strength and both nicotine arms are combined in our main analysis