One group crossover trial to answer the following question:
- Does the taste of the plain packaged cigarettes really changed and differ from the branded cigarettes or it is a natural sensory change?
- Dose the plain packaged cigarettes cause more immediate coughing compared to the branded cigarettes?
- Dose smokers who smoke plain packaged cigarettes suffer more shortness of Breath compared to the branded cigarettes?
- Qualitative interview after the experiment to understand the results impact on the participant.
Exposure and Procedure:
Participants received 6 sequences of different random exposures to 3 plain packaged cigarettes (2 from the favorite brand and 1 other brand “control”) and 3 branded cigarettes (2 from the favorite brand and 1 other brand “control”). With a wash-out period of 5-10 mins between each cigarette. To ensure reproducibility all participants were invited to repeat the trial in another day.
The standard cigarette in Saudi Arabia is approximately 5.5 Centimeters long excluding the filter, thus, for harm reduction reasons the smoker will be exposed to approximately 3 puffs which represent around 2 Centimeters. To ensure that the smoker does not exceed this amount an aluminum foil will be wrapped around the rest of the cigarette.
To ensure concealment, the cigarettes were provided in random order by a blinding handler who are not involved in data collection and/or data analysis.
To blind participants from recognizing the type of cigarettes, the participant wore Virtual Reality Goggles (VR) accompany with a special software to alter the visual reality of the smoker (Figure 1). In addition, the participants wore medical gloves to alter the hand touch felling of the cigarettes.
Inclusion and exclusion criteria:
Participants were smokers 18 years old and above, who are currently smoking cigarettes and cleared upon physical assessment before the experiment.
Participants who are planning to quit smoking or in quitting stage are not eligible to participate in this study to reduce harm and ethically not altering their quitting process or plan. Participants who have any respiratory or cardiac disease, any taste related disorder (e.g. hypogeusia / ageusia) or any acute disease that affect taste or smell (e.g. Flu). Participants who shows any abnormal vital signs check before the study (fever, shortness of breath or elevated blood pressure).
Participants were invited form Sharik research participants database(17), which include around 6000 smokers via phone call and study information and consent were presented to them, if agreed eligibility conditions checked and if eligible, an appointment booked to come to the study place. Once arrived the researchers explained all the details of the study to the participants and written participant information sheet were provided. Participants who want to start the study were asked to sign the consent. Then their vital signs were checked.
data collection and outcome measure:
Data collection started with a quick interview survey including the age, gender, Fagerstrom Test for Nicotine Dependence, age start smoking, frequency of coughing last 2 weeks.
The main outcome measure for the taste will be via asking the participants to identify the type of cigarette they smoked (plain or brand) based on taste. In addition, asking the smoker to rate the taste of the cigarette on a scale from 1 to 7 (1=very bad taste and 7= very good taste) and the heat perception of the cigarette smoke (burning sensation) from 1 to 7 (1= acceptable and 7=unacceptable). Finally, the smoker will be asked if the cigarette is from his favorite brand or not).
The outcome measure for immediate coughing is an observation of any coughing event during the smoking or washout period for each cigarette.
The outcome measure for shortness of breath will be measured via self-reporting and peak flow test. The participants will repeat the test before and after each cigarette for safety reasons, however, the main measure here is the first cigarette comparison between (plain and brand) as it was delivered in random order for each participants. The reason for comparing only based on the first cigarette is that second cigarettes maybe of another type which will introduce contamination, in addition, to the accumulative effect of each experiment. The shortness of breath is defined on the peak flow if the reading is 40% less than the baseline before starting the first cigarette as readings of 50% less than the baseline is defined as the signal for medical alert.(18)
After finalizing the experiment, the participants were asked about their perception about the taste & health concerns claims circulated in the media about plain packaged tobacco to be compared to their initial opinion before the experiment.
- Participants recruitment started early January 2020 via phone interview.
- Each eligible participant were scheduled to visit the study facility to start the study which took around (60 mins)
- Participants then were invited to the second session within a week of the first session.
Based on the smokers complains on media channel it seems that the different in taste between the plain and branded cigarette are large to medium. Thus, A single-factor, repeated measures design with a sample of 18 subjects, measured at 6 time points to produce (108 experiment), achieves 80% power to detect a contrast using a multivariate T² test at a 0.05 significance level at 0.45 - 0.35 effect size.(19, 20) Sample size was calculated via PASS 2019, v19.0.3 using the above mentioned inputs.
Expected Results & Benefits:
- Inform the authority about the existence of difference in taste form a study on local subjects. As very few previous studies where done in other countries.
- Inform the Authority of any immediate harm on smokers using the plain packaged cigarette and help provide an evidence to end to the claims regarding the plain packaged cigarettes, which is currently a country-wide issue.
Descriptive statistics were used to describe the sample demographics, Mixed model analysis will be used to analyze repeated measures of taste related outcomes. T test will be used to analyze ability of participants to identify their favorite brand and T test were used to analyze the follow update due to the small sample size which prevented the use of the repeated measure mixed model analysis.
The study was performed in agreement with the Declaration of Helsinki. Ethical Approval were obtained from Alfaisal University (Institutional Review Board).