Journal of Addiction & Prevention
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Review Article
‘I Think Smoking’s the Same, but the Toys Have Changed.’ Understanding Facilitators of E-Cigarette Use among Air Force Personnel
Little MA1*, Pebley K2, Porter K1, Talcott GW1,3 and Krukowski RA4
1University of Virginia, School of Medicine, Department of Public Health Sciences, 560 Ray C. Hunt Drive, Charlottesville, VA, USA 22903,
2University of Memphis, Department of Psychology, 400 Innovation Drive, Memphis, TN, USA, 38152
3Wilford Hall Ambulatory Surgical Center, 59 MDW/ 59 SGOWMP, 1100 Wilford Hall Loop, Bldg 4554, Joint Base Lackland AFB, TX, USA 78236
4Department of Preventive Medicine, University of Tennessee Health Science Center, 66 North Pauline Street, Memphis, TN, USA 38163
*Address for Correspondence: Little MA, University of Virginia, School of Medicine, Department of Public
Health Sciences, 560 Ray C. Hunt Drive, Rm 2119 Charlottesville, VA, USA, 22903; E-mail: mal7uj@virginia.edu
Submission: July 24, 2020;
Accepted: August 28, 2020;
Published: August 31, 2020
Copyright: © 2020 Little MA. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Abstract
Background: The military has stringent anti-tobacco regulations for new recruits. While most tobacco products have declined in recent
years, e-cigarette use has tripled among this population. However, little is known about the factors facilitating this inverse relationship.
Objectives: Examine the facilitators of e-cigarette use during a
high risk period following initial enlistment among young adults.
Methods: Focus groups were conducted with Airmen, Military
Training Leaders (MTLs) and Technical Training Instructors (TTIs) to
qualitatively explore unique characteristics of e-cigarettes leading to
use in Technical Training.
Results: The most commonly used tobacco product across
participants was cigarettes (42.7%), followed by e-cigarettes (28.0%)
and smokeless tobacco (22.6%). Almost a third (28.7%) of participants
reported using more than one tobacco product. E-cigarette use was
much more common among Airmen (76.1%), compared to MTLs
(10.9%) and TTIs (13.0%).
Four main facilitators around e-cigarette use were identified
including: 1) There is no reason not to use e-cigarettes; 2) Using
e-cigarettes helps with emotion management; 3) Vaping is a way of
fitting in; and 4) Existing tobacco control policies don’t work for vaping.
E-cigarettes were not perceived as harmful to self and others, which
could explain why Airmen were much less likely to adhere to existing
tobacco control regulations. Subversion was viewed as the healthy
option compared to utilizing designated tobacco use areas due to
the potential exposure to traditional tobacco smoke. This coupled with
a lack of understanding about e-cigarette regulations and difficulties
with enforcement, promoted use among this young adult population.
Conclusion: Findings suggest that e-cigarettes are used for similar
reasons as traditional tobacco products, but their unique ability
to be concealed promotes their widespread use and circumvents
existing tobacco control policies. In order to see reductions in use,
environmental policies may need to be paired with behavioral
interventions at the personal and interpersonal level.
Keywords
E-cigarettes; Vaping; Electronic cigarettes; Military; Young adults; Designated tobacco use areas; Policy
Introduction
With the introduction of electronic cigarettes (e-cigarettes) to
the market in 2006, there has been a dramatic increase in their use. A recent nationally-representative survey in the United States (U.S.)
indicates that past 30-day e-cigarette use among 18-24 year olds
has increased significantly from 2.4% in 2013 to 7.6% in 2018 [1,2].
Similarly, during that same time period e-cigarette use increased from
5.4% to 15.3% among 43,597 newly enlisted Airmen (called Airmen
regardless of gender or rank) surveyed about their tobacco use prior
to enlistment [3].
Although some of the increase in e-cigarette use is based on
their perceived safety over conventional cigarettes [4], much is still
unknown about the health risks associated with using e-cigarettes.
Recent literature suggests that e-cigarettes may place users at
increased risk for lung disease due to exposure to high levels of
ultrafine particles and other toxins [5-7]. Additionally, e-cigarette use
is associated with increased use of other tobacco products one year
later among recently enlisted Airmen. Klesges et al. found that current
e-cigarette-only users at baseline were 6.4 times as likely to convert
to conventional cigarette use and 10.1 times as likely to convert to
non-cigarette tobacco product use (e.g., smokeless tobacco, hookah,
cigars) at a one year follow-up when compared to never-users [3].
Given the conversion rate between e-cigarettes and traditional
forms of tobacco (e.g., cigarettes and smokeless tobacco), the health
impact of traditional tobacco, and the probable health effects from
e-cigarette use alone [5], the growing prevalence of e-cigarette use
among young adults may increase health risks while leading to
significant financial costs, particularly for young adults entering
the military. For instance, the Department of Defense (DoD)
spends on average $1.6 billion annually treating tobacco-related
morbidity among active duty military personnel (e.g., medical care, hospitalizations, lost work days) [8].
Although the military has taken steps to reduce tobacco use
over the past several decades, traditional policies may be limited
in their effectiveness for non-cigarette tobacco products, such as
e-cigarettes. Airmen have an enforced abstinence period during Basic
Military Training (8 ½ weeks) and the first four weeks of Technical
Training which appears to reduce cigarette smoking by 18% among
Airmen who reported smoking prior to joining the Air Force [9].
Furthermore, Airmen are not allowed to use tobacco during the duty
day (between breakfast and dinner) throughout Technical Training
[10], which can last up to 18 months; however, the effectiveness of
this policy is unclear. A previous review of the literature found that
while interventions may reduce the rate of illegal sales to youth
initially, lack of enforcement and the ability for youth to acquire
tobacco from social sources may undermine their effectiveness [11].
In the Air Force, the majority of former users of traditional tobacco
products re-initiate after the ban is lifted and many non-users start
using tobacco for the first time in Technical Training [12,13]. While
even less is known about the effectiveness of these policies with regard
to e-cigarette use, this high rate of (re)initiation suggest that other
factors, such as peer influences or enforcement issues may limit the
effectiveness of these environmental interventions.
In October 2019, the DoD removed e-cigarettes from its shelves
[14]. Unfortunately, research suggests that Airmen do not primarily
purchase e-cigarettes on base, limiting the potential effectiveness
of an on-base availability policy for e-cigarettes [15]. Targeted
marketing and price promotions for military personnel may further
reduce the effectiveness of DoD policies. For instance, JUUL, a
leading e-cigarette company, recently launched the heroes.juul.com
website, which is devoted to targeted marketing (e.g., promotional
videos featuring active duty and veterans) and price promotions (e.g.,
$1 dollar JUUL starter kits) for military personnel and veterans [16].
Therefore, it may be necessary to fully explore the environmental
facilitators of e-cigarette use, as the most promising solutions to
decrease use may be different from the traditional toolbox. Given
the high prevalence of e-cigarette use among new recruits entering
the military, understanding the facilitators of e-cigarette use in
the military population may be an important bellwether for other
vulnerable populations (e.g., non-college attending young adults).
Thus, the current study sought to identify facilitators of e-cigarette
use at a personal (e.g., individual-level characteristics, beliefs, and skills
related to tobacco use), interpersonal (e.g., friend and social network
influences), and environmental level (e.g., cultural values, norms
and the built environment) among Airmen undergoing Air Force
Technical Training. Given that most of the tobacco use (re)initiation
has traditionally occurred during Technical Training [12,13,17], it
is important to understand what factors are influencing Airmen to
use e-cigarettes during this high risk time, particularly since they
are increasing in popularity and existing tobacco regulations may
be limited in effectiveness. These findings will inform intervention
and policy efforts for youth and young adults who have similarly
experienced a rise in e-cigarette use due to targeted marketing and
price promotions [18].
Materials and Methods
This study is a qualitative exploration of the tobacco experience
of Airmen in Technical Training (referred to as Airmen for the
remainder of the manuscript), Military Training Leaders (MTLs) and
Technical Training Instructors (TTIs). Data were collected as part of
a larger study exploring factors predicting tobacco use among Airmen
during Technical Training. This paper presents findings relevant to
personal, interpersonal, and environmental facilitators of e-cigarette
use. In this study, we discuss the results of focus groups with Airmen
undergoing Air Force Technical Training, as well as focus groups of
MTLs and TTIs across the five largest Technical Training schools
where the majority of non-prior service Airmen are trained. Study
procedures were approved by the 59th Medical Wing Institutional
Review Board.
Participants and recruitment:
We conducted a total of 22 focus groups (N=164 participants)
among Airmen (n=10), MTLs (n=7), and TTIs (n=5) from July 2018
to February 2019 at Joint Base San Antonio - Fort Sam Houston and
Lackland Air Force Base (AFB), Goodfellow AFB, and Sheppard
AFB in Texas and Keesler AFB in Mississippi. MTLs are the direct
supervisors of Airmen, ensuring they are where they are supposed
to be and dispensing disciplinary action. TTIs are responsible for
teaching the specific skills required for that career field. While MTLs
are always active duty, TTIs can be active duty or civilians (typically
Airmen who have separated or retired from the military). For this
study, Airmen volunteers were recruited during their out-processing
week at the end of their Technical Training when they were receiving
health-related briefings. MTL and TTI volunteers were recruited
through a recruitment email sent by the Senior MTL at each base.
Participants had to be at least 18 years of age and could be either a
tobacco or non-tobacco user.Focus group procedures:
Protocols for the focus group were developed for users and nonusers
as well as MTLs and TTIs. The focus group questions targeted
the following domains: (1) personal experience with tobacco, (2)
facilitators of tobacco use on base, (3) barriers to tobacco use on base,
and (4) strategies to reduce tobacco use among Technical Trainees.
This paper focuses specifically on data related to e-cigarette use.Focus groups were conducted by two of five trained non-military
researchers in a private room without leadership present in order to
promote an open and safe environment. Each focus group contained
one moderator and at least one note-taker. Participants were
provided with an informational consent letter and verbally consented
to participate. Focus groups contained, on average, 7 participants,
ranging from 4 to 11 participants, and took on average 45 minutes to
complete. Airmen focus groups were separated by tobacco use status
(n=7 with tobacco users, n=2 with non-users, n=1 with users and
non-users). All MTL and TTI focus groups were mixed with tobacco
users and non-users. Participants were provided with food during the
focus group. Responses were anonymous and audio-recorded.
Analysis:
Transcripts of focus groups were transcribed by Datagain.
Transcripts were checked by researchers before coding. A hybrid deductive-inductive approach was used to code transcripts. Two
trained research staff members coded each transcript. Coders met to
resolve discrepancies and came to agreement. If an agreement could
not be reached, a third coder was brought in to resolve discrepancies.
The research team used NVivo (v12) software to manage the coding
process.To facilitate the first pass of coding, a codebook was developed
using the social ecological model, overarching research questions
from the grant, and evidence from the literature. As mentioned above,
the primary domains within this initial codebook were facilitators
and barriers of tobacco use during training, personal experiences with
tobacco and strategies to reduce tobacco use among trainees. Initial
codes within domains were identified based on the literature. Next,
researchers reviewed meaning units within each discrete code to
ensure adherence to operational definitions and to determine whether
codes should be merged or sub-coded. Additionally, meaning units
within codes were categorized based on the specific tobacco product
mentioned, including e-cigarettes. Finally, individual codes were
organized into larger categories.
Results
Of the 164 participants, 83 (50.6%) were Airmen, 48 (29.3%)
were MTLs and 33 (20.1%) were TTIs. The majority of participants
were male (77.4%) and tobacco users (72.0%). The most commonly
used tobacco product across all participants was cigarettes (42.7%),
followed by e-cigarettes (28.0%) and smokeless tobacco (22.6%).
Almost a third (28.7%) of participants reported using more than one
tobacco product. E-cigarette use was much more common among
Airmen (76.1%), compared to MTLs (10.9%) and TTIs (13.0%).
Airmen, MTLs and TTIs were asked what about the Technical
Training environment facilitates tobacco use. Four main facilitators
around e-cigarette use were identified including: 1) there is no reason
not to use e-cigarettes; 2) using e-cigarettes helps with emotion
management; 3) vaping is a way of fitting in; and 4) existing tobacco
control policies don’t work for vaping. Facilitators are described in
detail in the following sections and supported by quotations from
Airmen, MTL and TTI focus group participants in Tables 1-4.
No reasons not to use e-cigarettes:
A number of reasons emerged under the idea that there is no
reason not to use e-cigarettes (Table 1). Specifically, Airmen, MTLs and TTIs mentioned that e-cigarettes had many positive attributes,
were not perceived as harmful, were cool gadgets and were seen as
easy to use.Airmen, MTLs and TTIs all discussed the perception that
e-cigarettes are not (perceived as) harmful. One Airmen said,
‘Vaping is hardly tobacco.’ A MTL thought that Airmen don’t realize
the harms of e-cigarettes, and think ‘this smells like bubble gum so
I’m just gonna do it.’ A TTI said, ‘it doesn’t smell and you can get
the same nicotine, but it has got this flavor and it doesn’t taste like
a normal cigarette. You can get chocolate or strawberry or bubble
gum.’ E-cigarettes were also seen as not harmful in terms of time
required; a TTI said, ‘You just hit it once and you are done…Instead
of lighting up a cigarette and letting it burn.’
Several MTLs thought that Airmen used them because they were
‘electronic’, ‘cool lights and stuff, like they can get different colors and
it’s like cooler than their phone…and they can look like a dragon.’
They also mentioned that Airmen ‘like to do “smoke tricks” with
the devices.’ E-cigarettes were frequently referred to as ‘faddish’,
particularly in certain career fields, such as ‘an electronics career field’
(Airman).
Using e-cigarettes helps with emotion management:
Another consistent reason that was identified was emotion
management. This included using e-cigarettes to cope with the high
stress nature of Technical Training as well as periods of time when
they have nothing to do, particularly on weekends and after the
duty day (Table 2). One Airmen described the challenging training
environment as follows: ‘You ever been in a math class and the
question is four plus four, and you know the answer is eight, but they
tell you it’s seven? That is exactly how the past three months of our
lives have been.’ Another Airmen mentioned how the perception
that vaping could relieve stress promoted its use among Airmen
in Technical Training. Similarly, several Airmen felt that using
e-cigarettes ‘helps you concentrate…it kind of woke me up. It works
sometimes better than caffeine.’ Some Airmen mentioned that they
just enjoyed the act of smoking, ‘it passes the time and it’s relaxing
to me.’E-cigarette use was also seen as an activity that the Airmen
could engage in to manage boredom. A Military Training Instructor
mentioned that in Technical Training, there is ‘nothing else to do’
during their free time. Another instructor pointed out that because ‘the majority can’t drink,’ because they are underage, vaping is
‘something else that they do.’
Vaping is a way of fitting in:
Another facilitator of vaping in Technical Training was that it
was spread through peer interactions, socially accepted, part of the
culture, and the social thing to do (Table 3). One TTI described it as,
‘I think smoking’s the same, but the toys have changed.’ MTLs also
mentioned that vaping was spread through ‘peer to peer’ interactions.
Supporting this idea, a number of Airmen mentioned borrowing
an e-cigarette for the first time in Technical Training from a fellow
Airman. Airmen, MTLs and TTIs all discussed how common it was
for Airmen to vape in their rooms, even with a roommate that didn’t
use tobacco. Several MTLs mentioned that Airmen were not always
willing to report to the MTLs when their roommates were vaping in
their rooms. Vaping was also seen as part of the culture of Technical
Training, and popular among certain career fields. A number of
Airmen mentioned how vaping had a social component in Technical
Training. One Airmen mentioned that they go to the designated
tobacco use areas outside of their dorms for social reasons, while a
TTI said Airmen have vaping parties where ‘they see who can blow
out the most smoke.’Existing tobacco control policies don’t work for vaping:
Existing tobacco control policies were seen as ineffective given
that e-cigarettes are easy to conceal and use in your room, current
designated tobacco use areas were not attractive to e-cigarette users,
and the difficulty in enforcing current e-cigarette policies (Table 4).
A consistent theme from Airmen, MTLs and TTIs was that Airmen
were vaping in their dorm rooms, computer labs, bathrooms and
classrooms despite policy restrictions limiting their use during the
duty (training) day and restricting tobacco use to designated areas
around the military base.One reason Airmen reported using e-cigarettes outside of the
designated tobacco use areas was that they felt they were easy to
conceal. Airmen were not concerned about getting caught with them
because some e-cigarettes are small and the pod (which contains
the nicotine liquid) can easily be removed. Therefore, if they did get
caught with one on them they could remove the pod and wouldn’t
get in trouble for having it when they weren’t supposed to during
their duty day (e.g., when they were in class or training). In fact, some
Airmen even mentioned that although they liked the modifiable
e-cigarettes more than the smaller rechargeable pod e-cigarettes
(e.g., JUUL e-cigarette), they chose to keep ‘stealth’ e-cigarettes with
them during the duty day. One Airman even demonstrated how they
could easily put a small rechargeable pod e-cigarette in the upper arm
pocket of their uniform and use it without anyone knowing what they
were doing.
Many Airmen reported vaping in their rooms. Even among those
who went to the designated tobacco use areas, many still reported
vaping in their rooms. Several Airmen mentioned that leaving their
room to go to the designated tobacco use area felt like a hassle because
of the heat or it wasn’t worth making a trip all the way outside.
Airmen also reported vaping in their dorm rooms was because they
didn’t want to be exposed to secondhand smoke at the designated
tobacco use areas. Airmen mentioned that when they visited the
designated tobacco use areas they ‘got a headache because there were
so many different things going on.’ There was also some confusion as
to whether the Airmen are allowed to use e-cigarettes in their rooms.
One Airman when asked if they were allowed to use e-cigarettes in
their dorm rooms said, ‘I have no idea, but I do it.’ While another
Airman said, ‘I forget [the rule] all the time.’ Many Airmen felt like
the rules were not enforced. However, the MTLs and TTIs expressed
how it was hard to catch Airmen in the act of vaping.
Discussion
The current study sought to identify facilitators of e-cigarette
use among Airmen undergoing Technical Training for the purpose
of informing future intervention and policy efforts for youth and
young adults. While use was initially motivated by factors that
have been previously associated with traditional forms of tobacco
(e.g., entertainment value, flavor options, and use as an emotion
regulation tool), continued use was facilitated by the unique design
of e-cigarettes which allowed for users to easily circumvent existing
tobacco control regulations.
Airmen’s use of e-cigarettes was motivated by several perceived
benefits, such as their entertainment value and use as an emotion
regulation tool. Airmen reported using e-cigarettes to help them
relax or calm down, or even to help them concentrate. These findings are similar to reasons given for use of other non-cigarette tobacco
products, like hookah. Young adults have reported using hookah
because of the social aspect, they enjoyed the taste, and smoking
hookah produced a calming/relaxation effect [19]. Additionally,
Airmen in the sample were drawn to the features of the e-cigarettes,
such as lights, flavors and the ability to do smoke tricks. Previous
literature has shown that flavors are a primary reason for e-cigarette
use among young adults [20-23]. However, in 2020, the Food and
Drug Administration (FDA), banned mint- and fruit-flavored
e-cigarette liquids except for larger, less discrete tank-based systems
or disposable pods. It remains to be seen how this new limitation
will impact e-cigarette use among young adults, given that most
e-cigarette users purchase flavors other than tobacco [20].
Use of e-cigarettes was reinforced by the unique design of
e-cigarettes, affording users with a product that is both discrete
and easy to use. Despite explicit policies banning the use of tobacco
products during the duty day, many Airmen mentioned that
e-cigarettes could easily be concealed and used throughout the day.
Previous studies have found that stealth vaporisers, like JUUL, which
resemble ordinary devices like USB sticks, are often not recognized
by adults, and are therefore popular among youth and young adults
[24,25]. Use indoors was also commonplace in our sample, with
participants reporting use in bathrooms and their dorms despite
explicit rules against use outside of designated tobacco use areas. The
nature of using an e-cigarette (e.g., the ability to take a drag every few
minutes), promoted their use outside of designated areas; it didn’t
make sense to Airmen to go all the way to the designated tobacco use
areas for a drag. Additionally, many Airmen avoided the designated
tobacco use areas because they did not want to be exposed to the
secondhand smoke from burnt tobacco. It may be the case that having
one catch-all tobacco use area that encompasses all types of products
may not be a viable or acceptable option for e-cigarette users.
In addition, a factor that complicated this situation was the
difficulty of catching Airmen using in places or at times that they
were not supposed to, making these rules difficult to enforce. School
districts around the U.S. are facing similar challenges, and as a result
have enacted school-wide flash drive bans, removed the main doors
from student bathrooms and installed vapor detectors [24]. In order
to combat the increase in e-cigarette use among Airmen in prohibited
areas, the Air Force may need to consider implementing similar
measures.
There was also a pervasive theme related to the belief that
e-cigarettes were not harmful, and there was no concern for e-cigarette
secondhand smoke as evidenced by use in dorms with non-smoking
roommates. While e-cigarette secondhand smoke does not contain the
same toxicants as a traditional cigarette, there may be other reasons
for health concern. Studies have shown that e-cigarette users exhale
some of the mainstream vapor, which exposes bystanders to harmful
constituents including heavy metals, nicotine, ultrafine particulates,
volatile organic compounds and other toxicants [26-28]. Another
reason for using in places where e-cigarettes were prohibited was
confusion about whether e-cigarettes were considered tobacco. This
limited awareness of tobacco policies is similar to a study conducted
with 14 colleges and universities, which found that most students
did not know if their school included e-cigarettes in their tobacco policies, or if there were e-cigarette use policies despite the fact that
most students also reported being supportive of having such a policy
[29]. These findings suggest that there is a need for specific policies
related to e-cigarettes, and concerted efforts to raise awareness about
these policies may help clarify the inclusion of e-cigarettes and limit
e-cigarette use. However, additional research is needed to examine
the role that awareness of policies has on e-cigarette use behaviors.
An additional consideration is the implementation of the new
federal Tobacco 21 law, which prohibits the sale of tobacco to anyone
under the age of 21 even if they are military personnel [30]. Almost
half of Airmen are under the age of 21 and thus are no longer able to
buy their own e-cigarette products [20,31]. A common facilitator at
the time of the focus groups (conducted prior to the implementation
of the Tobacco 21 law) was that e-cigarette use was something
Airmen could legally do given there were not a lot of ways Airmen
could spend their free time. With this new legislation, Airmen will no
longer be allowed to purchase tobacco if they are under 21, but will
still be allowed to use tobacco [30]. This could lead some Airmen that
are of age to purchase tobacco products for underage Airmen, which,
if enforced similarly to the rules around alcohol use in the military,
would be classified as ‘contributing to a minor’ and be a punishable
offense leading to a delay in training or even early discharge. Given
that the Air Force already loses $18 million annually on excess
training costs associated with smoking [32], it is likely that this
number will increase under the new legislation. Additional research
is needed to determine if this new regulation is effective at reducing
e-cigarette use among youth and young adults, or if they simply get
these products elsewhere, such as from a friend or roommate, which
may require the Department of Defense to take additional steps to
strengthen their approach to tobacco control. For instance, in the
United Kingdom, plain packaging and a smoking ban in cars with
minors was recently enacted, while other European countries are
striving to reduce the prevalence of youth smoking to under 5% in the
next 15-20 years [33,34]. To achieve this goal, countries like Ireland,
Scotland, Finland, France and the Netherlands have all adopted more
stringent tobacco control policies, such as plain packaging, point-ofsale
display bans and smoke-free playgrounds [33,34]. In 2016, the
Department of Defense put out a policy memo with a similar goal to
reduce tobacco use and secondhand smoke exposure by restricting
tobacco use to designated areas on base, creating multi-unit smokefree
military housing, and increasing the price of tobacco [35]. It is yet
to be seen how effective these policies will be at reducing tobacco use
among military personnel.
Strengths and Limitations
The current study was not limited to e-cigarette product use, and
therefore we did not assess all potential reasons for e-cigarette use,
or if specific themes were related to actual e-cigarette use behaviors.
However, the current study provides insights related to perceptions
and beliefs about e-cigarette use among a large and diverse sample
of young adults and can inform future e-cigarette policies and
interventions.
Conclusion
Results highlight how the unique design of e-cigarettes
coupled with perceptions that e-cigarettes are less harmful and
socially accepted promote circumventing existing tobacco control
regulations. In order to effectively reduce the growing prevalence of
e-cigarette use, existing policies and interventions will need to take a
systems approach, in which multiple levels of influence (individual,
community and environment) are considered.
Disclaimer
The opinions expressed on this document are solely those of the
authors and do not represent an endorsement by or the views of the
United States Air Force, the Department of Defense, the United States
Government or the National Institutes of Health.
Role of Funding Source
This study was supported by the National Institute of Drug Abuse
[DA043468]. The National Institute of Drug Abuse had no further
role in study design; in the collection, analysis and interpretation of
data; in the writing of the report; or in the decision to submit the
paper for publication.
Acknowledgements
The authors gratefully acknowledge the support of Second Air
Force, the leadership branch for training in the United States Air
Force.