Randomized within-subject trial to evaluate smokers' initial perceptions, subjective effects and nicotine delivery across six vaporized nicotine products

Abstract

Background and aims: Vaporized nicotine products (VNPs) can vary in important characteristics including size, shape, flavor and nicotine yield. We examined whether complex interactions among these characteristics could affect smokers' VNP perceptions and usage patterns.

Design: A within-subject randomized cross-over trial.

Setting: Roswell Park Comprehensive Cancer Center, Buffalo, NY, USA.

Participants: Eighteen daily cigarette smokers.

Measurements: Participants attended eight weekly visits during which they sampled six different VNPs (disposable, rechargeable, eGO, mod, e-Cigar and e-Pipe) with tobacco-flavored e-liquid. Prior to device use, participants completed product-ranking questionnaires. Participants completed controlled puffing sessions during each of the six trials, after which satisfaction questionnaires were completed and blood samples were taken.

Findings: Initial perceptions showed that the smallest device (disposable) was ranked as safer compared with a larger device (e-Pipe) (P < 0.05). Participants rated the eGO and mod devices higher on satisfaction and enjoyment from use, taste, pleasantness, harshness ('throat hit') and speed of effect, but lower on perceived health risk and embarrassment from use (P < 0.05). All devices had a lower C_max than the combustible cigarette (P < 0.05), but there were differences among devices (P < 0.05). The mod, e-Pipe and eGO provided the highest amount of perceived smoking urge relief, and this correlated strongly with C_max across all devices (R² = 0.8614, P = 0.007). The perceived speed of urge relief was not correlated with T_max (R² = 0.0035, P = 0.911) CONCLUSIONS: Daily cigarette smokers testing six types of vaporized nicotine products (VNPs) reported that they varied in taste, amount of withdrawal relief, harshness, embarrassment from use, perceived health risk and subjective and objective nicotine delivery. The eGO and mod models have properties that may make them most effective for cigarette substitution among smokers who intend to switch to a VNP.

Keywords: e-cigarettes; electronic cigarettes; electronic delivery systems; nicotine; vaping; vaporizers.

Figure 1.

Participant flow-chart.

Figure 2.

Average plasma nicotine profiles for each device and participants preferred brand tobacco cigarette.

Figure 3.

Subjective rating of various VNPs: (A) Satisfaction with VNPs. (B) Perceived harm of VNPs. (C) Enjoyment from using VNPs. (D) Speed of smoking urge relieve after VNP use. (E) Amount of urge to smoke relieved after VNP use. (F) Harshness of inhaled VNP aerosol. (G) Taste of inhaled VNP aerosol. (H) Pleasantness of inhaling VNP aerosol. (I) Embarrassment from using VNPs.

Figure 4.

Subjective rating of nicotine effects 3 minutes after use of VNPs: (A) Changes in Questionnaire of Smoking Urges-Brief (QSU-B) scores after VNP use (left) and comparison of VNP effects 3 minutes after use (right). (D). Changes in smoking urges after VNP use (left; corrected for baseline) and comparison of VNP effects 3 minutes after use. (C). Changes in Minnesota Nicotine Withdrawal Scale (MNWS) scores after VNP use (left; corrected for baseline) and comparison of VNP effects 3 minutes after use

Figure 5.

(A) Correlation between median C_max with subjective urge relief after use of various Vaporized Nicotine Products (VNPs); (B) Correlation between median T_max with perceived speed of urge relief after VNP use; (C) Correlation between perceived harshness of device and pH of refill solution.