A Prospective Pilot Study of the Allurion Digital Behaviour Change Intervention

Obesity and Intragastric Balloon Treatment
Obesity is a chronic, debilitating, multi-factorial disease that has reached
worldwide pandemic proportions1. The prevalence of obesity has tripled since
the 1980s in many countries of the World Health Organization (WHO) European
region. In addition, the prevalence of overweight and obese people in the
United Kingdom (UK) continues to increase at an alarming rate and is a trend
that will be difficult to reverse. The WHO estimates that by 2015, 2.3 billion
people will be overweight and over 700 million will be obese. Furthermore, the
movement of people into the obese category (Body Mass Index (BMI) > 30)
continues to increase by 1% of the population per year2, and within this group
the percentage of people moving into the Class III, or morbid obese group, has
almost doubled over the last ten years with an estimated prevalence of 2.2%3.

Significant evidence indicates that successful treatment of obesity results in
a reduced incidence of co-morbid diseases. Specifically, a 5-10% total weight
loss can significantly reduce or prevent coronary heart disease,
hyperlipidemia, hypertension, type 2 diabetes, and other chronic diseases in
obese individuals4-8. A combination of calorie restricted diet, regular
physical activity, and behavioral modification with or without pharmacotherapy
has been utilised to treat obesity; however, a significant weight loss of 10 to
15% is rarely achieved or sustained9. For morbid obesity, bariatric surgery is
the only treatment option with sustainable weight loss10. However, some
patients with moderately increased BMI do not qualify for bariatric surgery or
prefer less invasive treatment modalities. In these patients, an intragastric
balloon (IGB) can help them adhere to lifestyle modification, preventing the
need for bariatric surgery. IGB treatment, in addition to lifestyle
modification, has been shown to be an effective short-term modality for weight
loss11.

The Elipse Gastric Balloon System, manufactured by Allurion Technologies, is
designed to not require endoscopic placement or removal. The balloon is
swallowed by the patient in the ambulatory setting without sedation,
anaesthesia or endoscopy. It is designed to reside in the stomach for
approximately 16 weeks, after which its degradable release valve opens enabling
the device to empty. The empty balloon transits the GI tract and is naturally
excreted. Since receiving European regulatory approval in 2015, more than
39,114 Allurion gastric balloons have been distributed and deployed in patients
in 38 countries through December 2020. Data from 1,770 consecutive Allurion
Gastric Balloon System patients (F 1264/M 506) treated in 19 centers across 7
countries in Europe and the Middle East were collected to evaluate weight loss,
metabolic parameters, and device performance. The mean baseline age was 38.8
years, mean baseline weight of 94.6 kg, and mean BMI was 34.4 kg/m2. After 4
months, overall mean weight loss was 13.5 ± 5.8 kg and mean BMI reduction was
4.9 ± 2.0 points. Percentage total body weight loss was 14.2 ± 5.0%. All
metabolic parameters (including LDL, HDL, and HbA1c) improved12.

Development of a Digital Behavioural Component for Improved Outcomes

Despite the Elipse Gastric Balloon System showing significant short-term
post-operative weight loss trajectories for many patients, these findings are
not universal primarily due to lack of adherence to lifestyle modifications. To
achieve maximum weight loss and prevent weight regain, it is recommended that
patients increase physical activity, decrease sedentary behaviours, and adhere
to dietary recommendations. Unfortunately, these patients often face numerous
challenges (e.g., transportation, geographical, time) that prevent them from
seeking further assistance or support to improve and prolong weight loss
outcomes. Current studies document the promising effects of use of mobile and
online technologies (eHealth), including wearable devices for improving health
outcomes among those with obesity by eliminating transportation, geographical
and time barriers13. Post-IGB weight loss and weight loss maintenance
interventions that are accessible, cost-effective and scalable are not only
desirable, but have the potential to improve and sustain health outcomes14.



The United States Preventive Services Task Force (USPSTF) and the Obesity
Society found adequate evidence that intensive,
multicomponent*behavioural*interventions in adults with obesity can lead to
clinically significant improvements in weight status. The USPSTF also found
adequate evidence that the harms of intensive, multicomponent behavioural
interventions (including weight loss maintenance interventions) in adults with
obesity are small to none. Therefore, the USPSTF concludes with moderate
certainty that offering or referring adults with obesity to
intensive*behavioural*interventions or*behaviour-based weight loss maintenance
interventions*has*a moderate net benefit15,16.*



The increasing prevalence and disease burden of obesity necessitate the
development of novel methods to support weight management17. Digital behaviour
change interventions (DBCI) have the potential to provide a tailored,
accessible, scalable and cost-effective solution for people with overweight and
obesity, with benefits extending to non-weight outcomes such as the reduction
of depression risk and depressive symptoms18. Current studies show that the
delivery of obesity treatment eHealth strategies is both cost effective and
scalable19,20. Many eHealth systems are used to set and track individual goals,
to monitor diet and physical activity and to create tailored responses based on
behaviour change progress. Specifically, in a meta-analysis of eHealth weight
loss or weight maintenance interventions Hutchesson et al. reported modest
weight loss compared with no behaviour treatment or minimal treatment. eHealth
interventions with features including self-monitoring and personalized feedback
or technologies such as text messages and social media were more effective than
standard eHealth programs21.



There is increasing evidence to support the use of DBCI in adults with obesity
and type 2 diabetes. Given that type 2 diabetes is one of the most prevalent
co-morbidities associated with severe obesity, it is logical to think that
these same strategies may be effective in pre- and post-IGB education,
knowledge, behaviour change and social support delivery. However, it is also
important to measure the acceptability of such strategies, and whether they
improve IGB outcomes. Das et al. reported that an eHealth portal tailored to
provide postoperative metabolic and bariatric surgery support decreased
attrition rates in clinical follow-ups and improved patients* health22.
Additionally, the portal became a safe outlet where patients could express
their concerns and seek assistance in real-time. It also allowed providers to
better tailor their care to meet the patients* needs.



No studies to date have specifically reported outcomes or effect sizes for
DBCIs targeting IGB patients. As such, there is an opportunity to develop
engaging and effective DBCI strategies and products targeting IGB patients.

Development of the Allurion Digital Behaviour Change Intervention

The Allurion DBCI adheres to current National Institute for Health and Care
Excellence (NICE) guidance for obesity23. This is illustrated by the following:

It is a multicomponent intervention, which is *treatment of choice* for
obesity.

It includes evidence-based behaviour change strategies to increase physical
activity/reduce inactivity, improve eating behaviour, quality of diet and
reduce dietary intake.

It is individualised for the person*s needs and circumstances.

It provides personalised and responsive support.

NICE guidance for obesity behavioural interventions also recommends inclusion
of the following strategies, some of which are commonly known in the
behavioural science literature as *Behaviour Change Techniques* (BCT):

Self-monitoring of behaviour and progress.

Stimulus control.

Goal setting.

Ensuring social support.

Problem solving/strategies for dealing with weight regain.

Cognitive restructuring.

Reinforcement of change.

Relapse prevention.

These strategies are implemented in the Allurion DBCI. Participants in this
study will be guided through a personalised DBCI, designed to improve dietary,
physical activity, sleep, self-regulation, mood and stress-related behaviours.
The program promotes participant autonomy and includes ongoing and iterative
feedback loops of self-monitoring, feedback, goal setting and action planning
strategies, behavioural control/regulation and revision of goals and action
plans.*



Behaviour modification in general and comprehensive lifestyle interventions
that incorporate evidence-based BCTs are currently the cornerstone of obesity
management. As might be expected, the key target outcomes for the Allurion DBCI
are changes in diet and physical activity. In order to achieve these outcomes,
it is necessary to identify the many target behaviours associated with success
in relation to these outcomes. In order to do this systematically, a well
recognised behavioural science framework - The Behaviour Change Wheel (BCW) was
used24.



The first stage sought to identify key target behaviours associated with the
outcomes, and then to understand the various barriers and facilitators that
individuals face in achieving these target behaviours. This included a rapid
review of the literature and review of qualitative and quantitative data
collection from previous Elipse Gastric Balloon System patients. An exploratory
mapping of the behavioural insights collected from this was achieved using a
theoretical framework within the BCW - the
Capability-Opportunity-Motivation-Behaviour Model (COM-B). The COM-B identifies
the factors influencing whether an individual has the
*Capability* (Psychological and Physical); the *Opportunity* (Physical and
Social) and the Motivation (Automatic and Reflective) to undertake the
necessary actions required to achieve weight loss and maintenance 24. This may
include environmental (e.g., physical, social) and individual factors (e.g.,
knowledge, emotions, motivation, behavioural regulation, cognitive skills). The
Theoretical Domains Framework (TDF) consists of 14 domains within the COM-B
that provide further details about the drivers of behaviour. Examples include
*Belief about Capabilities,* *Intentions,* and *Optimism.* Identifying these
factors is crucial in order to select the most suitable BCT techniques and
digital features will be implemented in a given program.* BCTs are described as
the core ingredients in a behaviour change intervention, known to be effective
at helping someone to change a behaviour and form a new habit. In the next
stage of the BCW, we identified appropriate *Intervention Functions* to include
in the DBCI: *Education,* *Enablement,* *Environmental Restructuring,* and
*Modelling.* We then utilised the Behaviour Change Technique Taxonomy
(BCTTv1)25, a list of 93 possible BCTs, to identify suitable BCT*s. Other
evidence-based psychological techniques from Cognitive Behavioural Therapy
(CBT) and Acceptance and Commitment Therapy (ACT) were also included.

Evidence Base for Weight Management BCT Inclusion

A taxonomy of BCTs specifically relating to physical activity and healthy
eating behaviours has been developed: the CALO-RE taxonomy26. This
behaviour-specific 40-item taxonomy precedes the broader 93-item BCTv1
taxonomy25. The following BCTs from the BCTv1 taxonomy and CALO-RE taxonomy
have been linked with more successful behavioural interventions, including
physical activity and improved diet, for obese adults: *provision of
instructions,* *relapse prevention,* *prompts and cues,* *goal setting,* *self-
monitoring of the behaviour,* *barrier identification/problem solving,* and
*plan for social support*27,28,29. These BCTs also link to the NICE guidelines
for obesity behavioural strategies, highlighted above. The BCTs *self-
monitoring,* *goal setting,* *instructions on performing health behaviour,* and
feedback on performance* have also been associated with higher quality apps for
improving health in adults30. As such, all of these BCTs were all included in
the Allurion DBCI.

Health Coaching

BCTs can be delivered face-to-face or in digital format. For the purposes of
this intervention, they will be delivered in digital form, but with real-person
in-app support, in real time. The support, including BCT content, is delivered
by a health coach. Health coaches are skilled in understanding the
environmental, social and psychological barriers an individual might encounter
in their attempts to lose weight; and what and how they can overcome these
using various evidence-based strategies.



Allurion health coaches will provide participants with personalised and
responsive support and assist with all aspects of the DBCI and BCT delivery.
Health Coaching can help people to gain the ability, knowledge and efficacy to
reach their own health and well-being goals31. Research has found that health
coaching can be beneficial for improving health, particularly for obesity. A
systematic review of trials exploring the effectiveness of health and wellness
coaching for improving nutrition-related biomarkers and eating behaviours
highlighted coaching as an *important strategy for the prevention and treatment
of obesity and chronic disease across diverse populations*32. Delivery of
health coaching via Tele-health and internet-based communication was also found
to be effective. An observational clinical study using health coaching for
weight loss in overweight/obese patients reported a mean loss of 7.24% initial
weight after 12 months33. Including health coaching in a DBCI can provide
flexible support for participants, allowing for the delivery of behaviour
change strategies. This can be particularly beneficial for delivering behaviour
change content as digital strategies have the potential to offer high fidelity
of delivery34.



Health coaches will oversee the principal components of the DBCI: goal setting
and action planning set by participants and reviewed weekly and support them in
whatever BCT*s and other approaches are appropriate to support this, tailored
to their needs. In particular, focus will be given to the following BCTs:

Weight Self-Monitoring

Self-monitoring or the systematic observation of one*s own*behaviour allows an
individual to become more aware of the*extent to which he or she is engaging in
a particular activity. Self-weighing alone has shown mixed effectiveness in
weight loss35,36. Self-regulation combined with self-weighing appears to be
more effective as the weight loss effect is due to a self-regulation mechanism,
based on the hypothesis that self-monitoring triggers self-regulation.
Self-regulation*is the ability to understand and manage your behaviour and your
reactions to feelings and things happening around you37. It includes being able
to regulate*reactions to emotions like frustration with lack of weight loss and
then to put in place goal actions to reach the goal of losing weight.
Therefore, alongside weight monitoring, participants will be supported by the
health coach to utilize skills in self-regulation. In this context,
self-regulation occurs in iterative cycles:

Contextualizing the weight with previous measurements and goals, which
provides,

An opportunity to reflect on previous behaviour and reinforce successful
actions, enabling,

The planning of actions to reach the goal,

Followed by performance of planned actions.

This cycle of processes allows for experimentation with different weight loss
techniques (weight loss actions), helping the user to build a personal
portfolio of effective and sustainable strategies. The Allurion DBCI is
underpinned by the evidence-base, including the PREVAIL trial3,38. In this
trial, the intervention group weighed themselves daily, tracked their weight in
an app and then selected a daily evidence-based weight loss action from a menu
of options. Participants completed daily and weekly questionnaires to prompt
action planning, reflection and evaluation of actions. The control group was
only asked to weigh themselves daily. Results found a mean weight loss of
-4.2kg compared to -1.0kg in the control (-3.2kg difference, 95% CI: -4.49,
-1.92) at 8 weeks. They also found high adherence rates and positive
intervention ratings which demonstrated that the intervention was feasible and
acceptable to participants. The Allurion DBCI will include psychological weight
loss actions in addition to those similar to the PREVAIL trial.



Another recent study demonstrated that consistency of self*weighing may be more
important than total frequency for preventing weight regain after the end of a
weight*loss program. Results found that self*weighing for >=6 days/week may be
necessary to promote successful weight*loss maintenance39. Therefore, promoting
daily weight self-monitoring, using the Allurion Scale, will be a goal for
trial participants.

Physical Activity and Sleep Self-Monitoring

Guidelines for adults in the UK recommend approximately 150 minutes of moderate
exercise training, broadly defined as anything that raises the heartbeat, or 75
minutes of vigorous activity, such as running, per week40. Similarly, the Dutch
Physical Activity Guidelines for adults recommend 150 minutes of weekly
moderate exercise41. A review of physical activity interventions for weight
loss demonstrated that following minimum recommendations may produce modest
(0.5-3%) but not clinically significant weight loss (>= 5%); however, following
guidelines may improve other clinical indicators, such as reductions in waist
circumference and body fat42. Increasing the intensity and duration of exercise
can result in additional weight loss43.



As the effects of intragastric balloons are only temporary, it is important
that use of such devices is combined with both lifestyle and behavioural
interventions and physical activity. This will aid long-term weight maintenance
once the balloon has been removed or deflated44. For this study, emphasising
the importance of physical activity, monitoring of dietary intake and
encouraging participants to maintain and self-report levels of physical
activity through the app will be important steps for the health coaches in
supporting participants to build the skills and efficacy to maintain weight
loss and prevent future weight gain.



Physical activity tracking and planning are key DBCI features related to
self-monitoring of behaviour and progress. It is also important to track sleep
as healthy sleep, in terms of quality and duration, has been linked to lower
body weight and may help to assist in sustaining weight loss following
bariatric surgery45. Maintaining a consistent time of sleep onset may also be
beneficial for weight loss management46. In this study, this type of tracking
will be automated and facilitated by a physical activity and sleep
sensor/tracker i.e., the Allurion Health Tracker (Watch). Health Tracker
feedback will be personalised by an Allurion health coach based on user
activity and sleep levels in relation to recommended and personalised goal
setting. Participants in the study will be asked to wear their Allurion Health
Tracker (Watch) at all times so that their sleep levels can be monitored by the
health coach.

Dietary Self-Monitoring

For weight loss, self-monitoring usually involves tracking food and drink
consumption47. By tracking meals via an established app, we will support users
to be able to quickly identify a behaviour that may have positive or negative
effects on the success or failure to meet their set goals.*Frequent tracking of
food (even though people typically underestimate their dietary intake by around
18%) is associated with increased weight loss. A systematic review exploring
the role of self-monitoring in weight loss found that weight loss was
significantly higher in participants who consistently returned completed
dietary self-monitoring logs. While it is unrealistic to expect participants to
track all food eaten, recording foods consumed at least 75% of the time is a
reasonable goal for self-monitoring intake and more likely to result in weight
loss48. Encouraging participants of weight loss interventions to self-monitor
their dietary intake is also likely to lead to positive behaviour change which
can help to maintain long term weight maintenance47.

Social Support

Digital social support can include communities or social networks - message
boards, user blogs, challenges, forums, closed groups (e.g., Facebook), group
chats (e.g., WhatsApp), celebration walls, etc. The evidence shows that
engagement with social network tools is correlated with longer engagement
times. In addition, increasing social embeddedness (no. of *friends*) has been
associated with greater weight loss. Social support is included as a BCT in the
Behaviour Change Taxonomy (BCTTv1) and is a good predictor of success during
weight maintenance. It has strong appeal to some people, via the ability to
interact with other people going through similar experience, coupled with 24/7
availability49. Social support can be helpful, but it should not be the primary
strategy used to motivate health behaviour change and therefore is just one of
a number of key BCTs in the Allurion DBCI.

Conclusion

The Allurion, evidence-based DBCI, has been designed to support participants to
modify their lifestyle behaviours. Sustained improvements in lifestyle
behaviours have been shown to support weight loss and weight loss maintenance.
This prospective, pilot study of the Allurion DBCI, will evaluate the
acceptability and impact of a personalised DBCI, delivered alongside the
non-digital Elipse Gastric Balloon System after-care support. To our knowledge,
this will be the first real world evaluation of a DBCI offered to intragastric
balloon patients. Positive findings from this translational research have the
potential to support improved outcomes for prospective Elipse Gastric Balloon
System patients.

To determine DBCI acceptability by examining how participants respond to the
intervention, their views, perceptions, thoughts, feelings, benefits and
barriers.

To determine DBCI acceptability by examining Elipse providers views,
perceptions, thoughts, feelings, benefits and barriers in relation to the
impact of the DBCI on trial participants.

To evaluate DBCI impact on participants health and psychosocial outcomes
including weight, body composition, physical activity, sleep, heart rate,
dietary intake, quality of life and psychological outcomes*known to influence
successful weight loss and maintenance. These include mood, anxiety,
Health-related Quality of Life (QoL) and overall well-being; self-efficacy and
ability to self-regulate emotions, thoughts and behaviours relating to weight
management.

This study is a prospective, non-randomized, pilot study to test the impact of
the Allurion Digital Behaviour Change Intervention in participants who have
been treated with the Elipse Gastric Balloon System. The study consists of the
following segments:

Screening and enrolment period (prior to or day of Elipse Gastric Balloon
System treatment)

All participants will take part in the Allurion DBCI for 6 months following
study enrolment

All participants will complete a 6-month follow-up assessment after completion
of the Allurion DBCI

The total study duration per participant including screening and enrolment is
anticipated to be approximately 13 months.

All participants will undergo standard treatment with the commercially
available Elipse Gastric Balloon System in accordance with the approved
Instructions for Use. The Elipse Gastric Balloon System treatment includes an
initial medical, nutritional and lifestyle assessment to determine suitability.
In appropriate cases, this is followed by placement of the balloon, followed by
after-care support. Standard support typically includes symptom, dietary and
lifestyle management from placement to 6 months, but does not include
behavioural modification and BCTs.


All patients undergoing the Elipse Gastric Balloon System treatment are
provided with the following as part of the standard treatment after-care:

Allurion*Scale - to measure their weight

Allurion Health Tracker Watch- to measure steps, exercise and sleep

Allurion Mobile App - to track and visualise scale and Watch data

Allurion nutritional education brochure


Allurion DBCI

This study will evaluate the impact of a personalised DBCI, delivered alongside
the standard after-care treatment support currently provided to Elipse Gastric
Balloon System patients. The Allurion DBCI is a multicomponent, theoretically
driven, and evidence-based behavioural intervention. Health coaching (delivered
via the Allurion Mobile App) will form the overarching mechanism with which the
majority of the intervention will be delivered.


Health coaches will support Elipse patients from balloon placement until 6
months. Health coaches will guide participants to improve their lifestyle
behaviours using well accepted behaviour change techniques known to enhance
outcomes in the obesity and weight management scientific literature. Allurion
health coaching participant support includes:

Setting goals using SMART goal setting framework.

Agreeing an action plan to help achieve goals and choose weight and health
related actions.

Weekly weight change progress review, feedback and problem solving.

Enhancing motivation and self-efficacy (using motivational interviewing12).

Social support and personalisation.

Providing tailored physical activity, nutrition and behaviour change content.

Psychological techniques offered as required to help support the development of
coping strategies associated with mood and eating, mindful eating and
recognising hunger and satiety, cravings and impulse control, environmental
drivers of weight loss actions; and techniques to enhance sustained habit
formation.

Weight self-monitoring and application of self-regulation techniques
(facilitated by the health coach and delivered via the Allurion Scale and
Mobile App)

Physical activity and sleep self-monitoring and application of self-regulation
(facilitated by the health coach and delivered via the Allurion Health Tracker
Watch and Mobile App)

Dietary self-monitoring and application of self-regulation (facilitated by the
health coach and delivered via commercial app meal tracking)

Social support (private, moderated, online community)

Health coaches will check-in with participants via in-app messaging weekly to
provide feedback on their progress, in relation to their weight change,
physical activity and sleep data. This will include a revision of their goals
and action plan to establish what worked and what didn*t, problem solve and
amend the actions as necessary. Participants will have access to the health
coach 7 days per week for brief questions and support.

In order for health coaches to effectively deliver the DBCI, participants will
be requested to:

Download the Allurion digital app (link will be provided)*

Weigh themselves with the*Allurion*scale at least weekly (preferably daily)*

Wear the*Allurion*health tracker (watch) as often as possible during the study*

Work with the health coach for six months post IGB balloon placement.

There is minimal risk to participants involved in this study. Study
participants will not undergo any investigational or additional medical
procedures as part of this study. Treatment with the commercially available
Elipse Gastric Balloon System will be conducted per the standard of care and is
outside the scope of this protocol. Due to the in-depth health coaching,
participants could become aware of a new medical condition by partaking in this
study.

Participants will engage in a number behaviour change interventions including
health coaching, health monitoring (i.e., weight, sleep, physical activity,
diet, etc.), and social support. This may result in improved weight control,
diet, physical activity, and/or sleep.

All data collected as part of this study will be either through the Allurion
Mobile or Web App, Scale, Health Tracker or participant questionnaires and
interviews, which presents a potential cybersecurity risk. However, all data
will be transferred and stored in a secure database with adequate controls in
place to ensure patient privacy including compliance with General Data
Protection Regulation (GDPR).