COMET Study 1: Filter Ventilated Cigarette Substitution in the ETM

The duration of the experiment will be approximately 3 months. Participants will begin with
an initial one week (approximately) exposure period to both unventilated and ventilated
cigarettes as well as alternative nicotine products (e-cigarettes, snus, etc.) that will be
made available throughout the experiment. Participants will be given the opportunity to
sample both types of cigarettes and alternative nicotine products. In the following sessions,
participants will alternate between Electronic Tobacco Marketplace (ETM) sessions and free
exposure periods to their assigned cigarette, with weekly assessments throughout to track
changes in smoking behavior and cigarette valuation. In total, participants will complete 10
experimental sessions (see Appendix B for experimental timeline figure). For the sake of
clarity, session types are separated below. The consent and initial sessions may take place
in the same or separate sessions.

At the beginning of the experiment, participants will be assigned to one of two groups:
ventilated or unventilated. Group assignment will determine what cigarettes will be given to
the participant after sessions in which they do not actually purchase their cigarettes of
choice. Additionally, participants that typically smoke menthol cigarettes will be given a
menthol version of their assigned cigarette. Cigarettes will be similar in design and will be
labeled as Typa A or Type B.

At the initial session and throughout the study, urine samples may be collected and stored
for testing (for tobacco use and pregnancy) and breath samples for carbon monoxide and
alcohol. Self-report may be used in place of urine analyses on a case-by-case bases. Urine
sample analyses for tobacco use may only take place at the VTCRI site.

Initial Assessment Session and Sampling (Session 1). First, participants will complete the
consenting process. The first session will be an assessment session to collect information
from participants on patterns and degree of tobacco and other substance use, perceptions of
all cigarette types available in the ETM, as well as the results of behavioral and cognitive
tasks that we think may inform or complement the results from the main study (see Appendix A
for a complete list and descriptions).

Participants will also complete the initial sampling period following the initial sampling
session. The goal of this period is to familiarize the participants with their randomly
assigned cigarette as well as alternative nicotine products. After their assessment session,
participants will be given a 7-day supply of ventilated and unventilated (3.5 days of
venitlated and 3.5 days of unventialted) cigarettes and asked to use these cigarettes. The
actual number of cigarettes delivered to each participant will be determined by multiplying
their reported cigarettes smoked per day by 7. Therefore, the average minimum number of
cigarettes that will be delivered is approximately 70 (10 cigarettes per day minimum to
qualify to participate). They will be also be given a sample of the alternative nicotine
products that will be made available during the Real-ETM sessions. Participants will be asked
to report their favorite flavor of each product to sample. If the participant is naïve to the
alternative nicotine product, they will be asked to estimate which product flavor they would
prefer. To verify usage during this and all subsequent usage period (see below), participants
will be asked to return spent cigarette filters in resealable bags we provide. However, while
participants will be asked to smoke the cigarettes they are given and to not use any other
cigarettes, they will only be asked to try the alternative nicotine products during the
sampling period, they do not have to finish them. A subset of these spent filters will be
randomly chosen and analyzed to permit correlation of mouth-level exposure to smoke
constituents with differences in ETM purchasing behavior between ventilated and unventilated
cigarettes. During this sampling period, participants will go about their daily lives,
allowing them to sample these cigarettes in the social environment in which they typically
operate. This "real-world" sampling period will serve to increase the generalizability of the
results obtained in the ETM sessions. This duration of exposure was chosen to give
participants time to begin to familiarize themselves with their assigned cigarettes. This
will enable them to make informed purchasing decisions during the upcoming sessions.

Real Experimental Tobacco Marketplace Sessions (Sessions 2,6, and 10).

Following the initial sampling period, participants will complete a purchasing session in our
realistic tobacco product marketplace. Participants will be seated in front of a computer to
access an online marketplace with an interface similar to many online merchants. This will
allow participants to browse through the products and add as many as they desire to the
virtual shopping cart. Each product will have the price clearly displayed along with an
image. Each ETM session will contain five pricing scenarios, in which we:

i. manipulate the price of participants' assigned cigarettes to assess demand in a context
with no other products available; ii. manipulate the price of participants' non-assigned
cigarettes to assess demand in a context with no other products available; iii. manipulate
the price of both assigned and non-assigned cigarettes in unison to assess simple preference
between the two; iv. manipulate the price of participants' assigned cigarettes while the
price of non-assigned cigarettes remains constant to assess the degree to which assigned
cigarettes substitute for non-assigned cigarettes;

a. In this task, alternative nicotine products (e.g., e-cigarettes, chew, etc.) may also be
available for purchase at a constant price.

v. manipulate the price of participants' non-assigned cigarette while the price of assigned
cigarettes remains constant to assess the degree to which non-assigned cigarettes substitute
for assigned cigarettes.

a. In this task, alternative nicotine products (e.g., e-cigarettes, chew, etc.) may also be
available for purchase at a constant price.

In each of these scenarios, the price-manipulated cigarettes will be available across a range
of prices (e.g., $0.12, $0.25, $0.50, $1.00, $2.00, and $4.00). Price-constant cigarettes
will be set to the median cigarette price in the community. Participants will use an
experimentally provided income (proportional to their real-world tobacco consumption) to
purchase from the ETM. At each price, participants will be asked to make seven days of
tobacco-product purchases from the ETM. After all 5 scenarios are complete for their assigned
cigarette, participants will receive the products they purchased from one randomly selected
price. Participants will be well informed of these procedures prior to purchasing. For those
seven days after marketplace sessions, participants will be asked to only use those products
they have purchased from the tobacco marketplace, and to not purchase any outside tobacco
products, to not sell or give away any of their purchases, and to not ask anybody else to
purchase products for them. We will strongly encourage participants to follow these
procedures, and to report any deviations from these procedures, which we will incorporate
into our statistical analyses. If the participant does not spend their entire income, they
will be allowed to keep the remainder. In this way, participants will be spending real money
and incurring a financial cost for their purchases, leading to more realistic product
selections. Following the seven days of using cigarettes obtained from the ETM, participants
will again visit the lab to return any unused products and report the use of experimenter
provided and non-experimenter provided tobacco products.

Extended Cigarette Exposure and Experimental Tobacco Marketplace Testing (Sessions 3, 4, 5,
7, 8, and 9).

Following the first session in the ETM and its associated period of tobacco product use,
participants will begin periods of freely provided exposure to their assigned cigarette
(ventilated or unventilated), alternating with two additional sessions in the ETM at regular
intervals. The purpose of this additional exposure between discrete ETM assessments is so
that we may examine the effects of sustained exposure to participants' assigned cigarettes at
regular intervals. During the extended-exposure periods, participants will visit the lab
every 7 days. At each of these sessions during extended-exposure periods, they will return
any unused cigarettes, report the use of experimenter provided and non-experimenter provided
tobacco products, receive cigarettes for the upcoming 7 days, and complete many of the
assessments they completed at their initial assessment session.

Following sessions 5 and 9 (the sessions immediately before the Real ETM sessions)
participants will be given 6 days of their assigned cigarettes and 1 day of the unassigned
cigarettes in order to expose the participant to the unassigned cigarettes before the Real
ETM session.

An abbreviated set of assessments will be collected on a weekly basis throughout the
experiment (Appendix A) in addition to any additional scheduled session (e.g., Real ETM).
These assessments will focus on measuring tobacco product use and measures of dependence and
withdrawal, including a Timeline Follow-Back for the period since the last session, as well
as product perceptions. We will also include a purely hypothetical version of the ETM (on
non-real ETM sessions), in which participants do not receive products purchased to use
outside the laboratory. Because these hypothetical ETM assessments can be repeated with
greater frequency and without interrupting periods of continuous exposure to assigned
cigarettes, data from hypothetical assessments will be used to inform determinations of the
effects of time on valuation of ventilated and unventilated cigarettes in more detail than
primary ETM assessments.

Inclusion Criteria:

- Current cigarette smoker

- Stable mental and physical health

- Does not take medications that interfere with nicotine metabolism

Exclusion Criteria:

- Pregnant or lactating

- Immediate future plans to quit smoking