Positive Psychology Intervention to Treat Diabetes Distress in Teens With Type 1 Diabetes
Phase: NA
Conditions: Type 1 Diabetes Mellitus
Sponsor: Vanderbilt University Medical Center

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
Diabetes (T1D) 
Version 7
Protocol 
11 April 2023
 
 
Thrive! Positive Psychology Intervention to Treat 
Diabetes Distress in Teens with Type 1 Diabetes (T1D) 
 
National Clinical Trial (NCT) Identified Number: NCT03845465 
Principal Investigator: SARAH JASER 
Sponsor: Vanderbilt University Medical Center 
 
Grant Title: Positive Psychology Intervention to Treat Diabetes Distress in Teens 
with T1D 
Grant Number: R01DK121316 
 
 
Summary of Changes from Previous Version: 
 
Affected 
Section(s)  
Summary of Revisions Made  
Rationale  
Protocol 
10/16/2019 
 
1) Use of econsent documents  
2) Updated 18-year-old consent 
document  
3) Revisions to measures (PAID-T and 
SCI) to reduce subject burden  
4) Additional measures to assess 
secondary outcomes  
5) Revisions to health behavior contract 
to broaden focus to other diabetes 
management behaviors  
6) Revisions to educational materials to 
improve readability  
7) Revisions to positive affect interview 
materials to improve clarity  
8) Revisions to recruitment script to 
include more information in the initial 
approach  
9) Study flyer 
1) Use of econsent forms to reduce paper and 
simplify enrollment process.  
2) Updated 18 year old consent forms to address 
request from IRB Analyst.  
3-8) Measures: Use of shorter, validated measures 
to assess outcomes to reduce participant burden.   
9) Developed study flyer to aid with recruitment. 
Protocol 
2/18/2020 
 
We reduced the required score on the 
diabetes distress measure completed by 
teens. We added a statement in the 
verbal consent to be able to collect 
clinical data (A1C) from participants that 
consent to screen for the study but do not 
enroll in the study. We are adding 
questions to the parental demographics 
survey to include more information 
about secondary caregivers. We are 
removing questions related to diabetes 
Based on lower than anticipated numbers screening 
into the study, we propose to reduce the required 
score on the diabetes distress measure completed 
by teens. We are adding a statement in the verbal 
consent to be able to collect clinical data (A1C) 
from participants that consent to screen for the 
study but do not enroll in the study. We are adding 
questions to the parental demographics survey to 
include more information about secondary 
caregivers. We are removing questions related to 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
Diabetes (T1D) 
Version 7
Protocol 
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device use that have been deemed 
superfluous or confusing. 
diabetes device use that have been deemed 
superfluous or confusing. 
Protocol 
4/20/20 
 
1) We added questions to the evaluation 
to ask about the effects of Covid-19 
on the participant's experience.  
 
2) We added an option to send the 
participant an at home A1C test if 
they did not have a diabetes clinic 
visit. 
1) In order to understand the impact COVID-19 
may have had on diabetes management and mood, 
we added questions to the teen and parent surveys.  
 
2) Due to the increase in telehealth visits, we are 
not able to obtain point-of-care A1C values from 
all participants. By sending at-home A1C test kits, 
we will reduce missing data. 
Non-Compliance 
11/2/2020 
8 participants (4 dyads) were given the 
incorrect compensation due to incorrect 
record keeping of Amazon gift card 
serial numbers. Gift cards worth $20 
were incorrectly recorded by study 
personnel as worth $30. Therefore, $20 
compensation was given to 4 dyads 
instead of the sufficient amount of $30. 
The study coordinator at Children’s 
National contacted each affected 
participant and sent the additional $10 
gift cards once the error was detected. 
 
Protocol 
11/2/2020 
Participants who use/have used a 
continuous glucose monitor (CGM) are 
given the option to participate in an 
ancillary study to take part in qualitative 
interviews about CGM use and reasons 
for starting and stopping use.  
This ancillary study will use qualitative interviews 
to explore the use of CGM in teens. 
 
Protocol 
3/23/2021 
We created a recruitment video that is 
used to give information to prospective 
participants about our study. We have 
also drafted language for distributing 
information about our study on Research 
Match and the Vanderbilt Research 
Notifications Distribution list to expand 
our recruitment efforts. 
Additional recruitment efforts to boost enrollment. 
Non-Compliance/ 
Continuing 
Review 
5/17/2021 
Many participants were recruited and 
enrolled through remote method due to 
Covid-19 restrictions. The HRPP 
allowed this change without prior 
approval due to extenuating 
circumstances. This protocol deviation 
detailed the covid-related changes we 
made.  
Covid changes in this protocol deviation included 
the following: Rather than approaching patients in 
clinic, we used Epic to track which patients were 
attending appointments through telehealth and 
called them to recruit for the study. Eligibility 
surveys were sent through email provided by the 
participant at the time of the call. − Rather than 
enrolling participant in the clinic, we enacted the 
same study protocols over zoom and sent study 
surveys through email. 
Measures 
8/26/2021 
We added questions to the parental 
COVID-19 supplemental measure. We 
are asking participants if any adults 
(18+) and children (12-17) have been 
vaccinated in their household. Also, we 
are asking if their child has seen their 
To remain current on how COVID-19 is affecting 
study participants, we added additional questions 
to our COVID-19 survey measure related to 
COVID-19 vaccination status and the use of 
telehealth clinic visits. Many COVID-19 
restrictions currently in place (locally and 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
Diabetes (T1D) 
Version 7
Protocol 
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diabetes provider via telehealth visit 
since this could impact their quality of 
care and one of our specific study aims 
(glycemic control). These changes were 
only applied to the parent surveys. 
domestically) are dependent on vaccination status, 
so these questions will help us to interpret findings 
related to the effects of COVID-19 on diabetes 
management and mood.  
 
 
 
 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
Diabetes (T1D) 
Version 7
Protocol 
11 April 2023
 
 
STATEMENT OF COMPLIANCE 
1. The trial will be carried out in accordance with International Council on Harmonisation Good 
Clinical Practice (ICH GCP) and the following: 
o 
United States (US) Code of Federal Regulations (CFR) applicable to clinical studies (45 CFR Part 
46, 21 CFR Part 50, 21 CFR Part 56, 21 CFR Part 312, and/or 21 CFR Part 812). 
National Institutes of Health (NIH)-funded investigators and clinical trial site staff who are 
responsible for the conduct, management, or oversight of NIH-funded clinical trials have 
completed Human Subjects Protection and ICH GCP Training. 
INVESTIGATOR'S SIGNATURE 
Principal Investigator or Clinical Site Investigator: 
Signed: 
Sarah S. Jaser 
Date: 
4/22/2019 
Name*:  
Sarah S. Jaser 
Title*:  
Associate Professor of Pediatrics 
 
 
Investigator Contact Information: 
Affiliation*:  Vanderbilt University Medical Center 
Address:  
2525 West End Ave., Suite 1200, Nashville, TN 37212 
Telephone:  615-343-6775 
Email:  
sarah.jaser@vumc.org 
 
For multi-site studies, the protocol should be signed by the clinical site investigator who is responsible  
for the day to day study implementation at his/her specific clinical site:  
Signed: 
  
Date: 
  
Name:  
Randi Streisand, PhD 
Title:  
Professor of Pediatrics 
Affiliation:  Children's National Medical Center 
 
 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
Diabetes (T1D) 
Version 7
Protocol 
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1 PROTOCOL SUMMARY 
1.1 SYNOPSIS 
Title: 
Thrive! Positive Psychology Intervention to Treat Diabetes 
Distress in Teens with Type 1 Diabetes (T1D) 
Grant Number: 
 R01DK121316 
Study Description: 
The proposed study will conduct a multi-site, randomized trial 
to test the effects of a positive psychology intervention aimed at 
treating diabetes distress and improving glycemic outcomes. 
Objectives*: 
Primary Endpoint: Glycemic control (HbA1c) 
Secondary 
Endpoints: 
Diabetes Distress 
  
Coping 
  
Positive Affect 
  
Diabetes Management 
  
Quality of Life 
  
Family Conflict 
Endpoints*: 
Primary Endpoint: 3 months 
Secondary 
Endpoints: 
6 months 
  
12 months 
Study Population: 
Adolescents with type 1 diabetes 
Phase* or Stage: 
Phase 2 
Description of Sites/Facilities 
Enrolling Participants: 
Vanderbilt University Medical Center Children's Diabetes Program 
Children's National Medical Center Diabetes Program 
Description of Study 
Intervention/Experimental 
Manipulation: 
The intervention is aimed at inducing positive affect to treat 
diabetes distress. Adolescents will complete a positive affect 
interview at baseline. They will receive automated text 
messages 5 days/week for 8 weeks. Messages will be tailored to 
include adolescents' responses to the baseline interview, 
including reminders to engage in gratitude and self-affirmation. 
Additionally, to induce positive mood they will be texted gift 
cards codes valued at $5.00. Further, parents will be asked to 
provide weekly positive affirmations to their adolescents, 
focused on non-diabetes strengths. After completing the exit 
interview participants will be given the option to participate in 
an interview exploring the role of continuous glucose monitors 
on diabetes distress and glycemic control. 
Study Duration*: 
4 years 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
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Participant Duration: 
12 months 
1.2 SCHEMA 
 
 
 
 
 
Enrollment n=200 
Randomization 
Baseline Data 
Collection 
TXT (n=100)  
PA Interview 
Parent Affirmation Training 
Education Packet 
Health Behavior Contract 
PA/Mood Booster 
Text Messages (5/week) 
Mood Assessment Text 
Messages (biweekly) 
Gift Cards (biweekly) 
Retention Item (4 weeks) 
Parent Praise Reminder  
Text (weekly) 
3 Month Follow-Up 
Data Collection & Exit 
Interview 
6 Month Follow-Up 
Data Collection 
12 Month Follow-Up 
Data Collection 
Mood Assessment 
Text Messages (biweekly) 
Retention Item (4 weeks) 
EDU (n=100) 
Education Packet 
Health Behavior Contract 
8 weeks 
First Study Visit 
Screening for 
Diabetes Distress 
Secondary study to 
assess the role of 
CGM on diabetes 
distress and glycemic 
control 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
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1.3 SCHEDULE OF ACTIVITIES 
  
  
Screening Visit 
1 
8 Week 
Intervention 
Period 
Visit 2 
(3 
months) 
Visit 3 
(6 
months 
Visit 4 
(12 
months) 
Diabetes 
Distress 
x 
  
  
  
  
  
Informed 
Consent/Assent 
  
x 
  
  
  
  
Outcome 
Evaluation 
  
  
  
  
  
  
Clinical Data 
(A1C, BG data) 
  
x 
  
x 
x 
x 
Adolescent 
Questionnaires 
  
x 
  
x 
x 
x 
Parent 
Questionnaires 
  
x 
  
x 
x 
x 
Randomization   
x 
  
  
  
  
Health Behavior 
Contract 
  
x 
  
  
  
  
Educational 
Materials 
  
x 
  
  
  
  
Positive Affect 
Interview 
  
x 
  
  
  
  
Automated Text 
Messages 
  
  
x 
  
  
  
Exit Interview 
 
 
 
x 
 
 
Optional CGM 
interview 
 
 
 
x (after 
visit 2) 
 
 
Adverse Events 
Reporting 
  
x 
x 
x 
x 
x 
  
  
 
 
 

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2 INTRODUCTION 
2.1 STUDY RATIONALE 
In line with the American Diabetes Association’s recommendation to assess for and address diabetes 
distress, the proposed project will focus on treating adolescents who report at least moderate levels of 
distress. We will use a positive psychology framework, which emphasizes positive emotions and 
strengths rather than problems, to treat diabetes distress and improve glycemic outcomes. Positive 
affect, defined as feelings that reflect pleasurable engagement with the environment (e.g., happy, 
cheerful, proud), predicts favorable health outcomes, especially in health conditions that have a 
behavioral component, like diabetes. Backed by empirical evidence from basic behavioral science, the 
Broaden and Build Theory posits that increased positive affect increases people’s ability to use complex 
coping strategies, such as problem solving and cognitive reframing, which are needed for the complex 
demands of diabetes management. The current study is based on the premise that, by boosting positive 
affect in teens with diabetes, we will enhance the use of adaptive coping strategies and reduce diabetes 
distress, thereby improving glycemic control. 
 
 
2.2 BACKGROUND 
Adolescents with type 1 diabetes (T1D) face increased risk for problems with management and 
deteriorating glycemic control, with only 17% of adolescents meeting the recommended target for 
hemoglobin A1C. Diabetes distress, or emotional distress related to the burden of living with diabetes, 
has been strongly associated with poor glycemic control and quality of life in adolescents. Unlike 
depression, which is episodic in nature, studies in adults with T1D show that diabetes distress remains 
stable over time without intervention.(4) Further, people who experience even moderate levels of 
diabetes distress have problems with diabetes management and glycemic control. While 
psychoeducational interventions have been proven to reduce diabetes distress in adults with T1D, to our 
knowledge, none have directly targeted diabetes distress in teens, and few have used positive 
psychology approaches. Thus, there is a need for novel approaches targeting diabetes distress to 
improve diabetes outcomes in adolescents with T1D.  
 
 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
Diabetes (T1D) 
Version 7
Protocol 
11 April 2023
 
 
 
3 OBJECTIVES AND ENDPOINTS 
OBJECTIVES 
ENDPOINTS 
JUSTIFICATION FOR 
ENDPOINTS 
PUTATIVE 
MECHANISMS OF 
ACTION 
Primary 
Glycemic Control 
(HbA1c) 
Baseline, 3 months, 6 
months, 12 months  
 Corresponding with 
diabetes clinic visits 
  
Secondary 
Diabetes Distress, 
Positive Affect, 
Coping, Diabetes 
Management, Quality 
of Life, Family 
Conflict, Resilience 
Baseline, 3 months, 6 
months, 12 months  
  
  
Tertiary/Exploratory 
Demographics 
(adolescent age, sex), 
use of diabetes 
devices 
 Baseline 
  
  
 
 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
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4 STUDY DESIGN 
4.1 OVERALL DESIGN 
To test the effects of the proposed intervention, we will recruit a sample of 200 adolescents with T1D 
and their parents from two clinical sites (Vanderbilt University Medical Center and Children’s National 
Medical Center, 100 dyads from each site). Adolescents will be eligible if they (1) are between the ages 
of 13-17; (2) have been diagnosed with T1D for at least 12 months; (3) score above the clinical cutoff on 
a screening tool for diabetes distress; and (4) speak and read English. The sampling goal for this study 
across the two sites is 68% white, 10% Hispanic, 16% Black, and 6% Asian, with equal numbers of boys 
and girls, in line with recent studies conducted in these settings.  
If the adolescent is eligible, the RA will obtain informed consent/assent, and the adolescent and his/her 
parent will complete the baseline measures. Participants will then be randomly assigned to one of two 
conditions: Positive Affect and Education (n=100) or Education only (n=100). Randomization will be 
stratified by use of diabetes devices (insulin pump and CGM), to avoiding confounding effects. A 
computer program will generate the randomization scheme. 
After completing the exit interview, participants who use/have used a continuous glucose monitor 
(CGM) will be offered the opportunity to participate in a secondary study to discuss the role of CGM in 
their diabetes management. 
 
4.2 SCIENTIFIC RATIONALE FOR STUDY DESIGN 
The age range (13-17) was chosen because it captures a key developmental stage, during which glycemic 
control often deteriorates. Adolescents who have been diagnosed with diabetes for at least 12 months 
will be studied to avoid confounding the effects of the initial adjustment period after diagnosis. A 
validated scale of diabetes distress in adolescents, the Problem Areas in Diabetes-Teens scale (PAID-T), 
will be used to screen adolescents for DD. A parent/Legally Authorized Representative will be eligible if 
he/she is currently living with the adolescent.  
4.3 JUSTIFICATION FOR INTERVENTION 
Education Only Intervention (EDU):  
The control condition (EDU) was selected based on positive affect studies in adults with chronic health 
conditions. Adolescents randomized to the EDU intervention will complete a health behavior contract, 
which has been shown to improve diabetes management in other studies of adolescents with T1D. The 
health behavior contract states the behavior that they are committing to do (e.g., check blood glucose 4 
times/day), when they will do it (e.g., before meals and before bedtime), and how often they will 
perform the target behavior (e.g., daily). They will also receive an education packet (14 pages) based on 
content from the American Diabetes Association website: www.diabetes.org) with appealing graphics 
and simple language. Additionally, adolescents will receive a retention item halfway through the 8-week 
intervention period.  
 
PA + Education Texting Intervention (TXT): 
In addition to completing the health behavior contract, adolescents randomized to the PA + Education 
intervention condition will complete the Positive Affect Interview developed in our pilot work. During 
the first study visit, a trained RA will guide the adolescents through the following empirically-validated 

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exercises to induce positive affect, and their answers will be included in the tailored text messages (see 
Table 1 for a description of PA components): 
1. Gratitude: Adolescents will be told that research shows that feeling happy helps people to 
handle challenges in their lives. We will ask them, “what are some small things that make you feel good, 
even for a few minutes (e.g., hearing your favorite song?”). Based on their answers, they will receive 
tailored text messages (updated weekly with new responses). “Last week you said [MUSIC] made you 
happy. Have you noticed that this week, even for a few minutes? (Please reply) Is there something else 
that has made you feel happy this week? Please reply yes or no (if yes: What is it?) That’s great!”  
2. Self-Affirmation: Adolescents will choose from a list of Important Values, based on self-
affirmation studies conducted with adolescents: Enjoying Sports, Art, Working Hard in School, Having a 
Sense of Humor, Being Creative, Belonging to a Social Group or Club, Following Politics or Current 
Events, Relationships with Friends, Relationships with Family, Faith or Spirituality, Music. The important 
value selected by adolescents will be piped into their tailored text messages. “You mentioned that [ART] 
was important to you. And I asked you to think about that when it was hard for you to take care of 
diabetes. Have you done that this week? (Please reply). Remember, focus on [ART] when it is time to 
take care of diabetes!  
3. Mood Boosters: Adolescents will also receive brief messages intended to boost their mood, 
similar to those used in other studies. In our pilot work, we asked teens to rate potential mood booster 
messages, consisting of inspirational quotes (e.g., “Keep your eyes on the stars and your feet on the 
ground - Theodore Roosevelt”) or jokes (e.g., “Q: What’s the difference between a fish and a guitar? A: 
You can’t tuna fish”). Based on their responses, we created Mood Booster message banks for younger 
teens (ages 13-14) and older teens (ages 15-17) consisting of the highest-rated messages. 
4. Unexpected Gifts: Adolescents will be sent an e-gift card code (worth $5.00) biweekly as 
another way to increase positive affect. Gifts that are viewed as useful and “delightful” are most 
effective at inducing positive affect; they do not have to be valuable. In exit interviews conducted during 
the pilot studies, adolescents reported using Amazon gift cards to download music, videos, and 
purchase small items, such as socks.  
5. Parental Affirmation: We will ask parents to provide praise or positive messages to their 
adolescents, focused on non-diabetes strengths (e.g., “I heard you practicing your guitar – sounded 
great!” or “I had a great time when we _____.”) Based on feedback from our pilot studies, we developed 
a protocol to instruct parents on the types of messages to send, including feedback on a sample 
message, to ensure that messages are consistent with the study goals. Parents will receive weekly text 
reminders at preferred times. By asking parents to provide affirmations rather than reminders for 
diabetes management, we hope to minimize parent-child conflict around diabetes care. 
 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
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5 STUDY POPULATION 
5.1 INCLUSION CRITERIA 
In order to be eligible to participate in this study, an individual must meet all of the following criteria: 
  
• 
Age 13-17 
• 
Diagnosed with type 1 diabetes for at least 12 months 
• 
Speak and read English 
• 
Report at least moderate diabetes distress on the Problem Areas in Diabetes Scale - Teen 
version 
 
 
5.2 EXCLUSION CRITERIA 
An individual who meets any of the following criteria will be excluded from participation in this study: 
1. Currently participating in another intervention 
2. Other serious health conditions that interfere with diabetes management 
5.3 STRATEGIES FOR RECRUITMENT AND RETENTION 
Enrollment. We will recruit a sample of 200 adolescents with T1D and their parents from two clinical 
sites (Vanderbilt University Medical Center and Children’s National Medical Center), 100 from each site. 
The sampling goal for this study across the two sites is 68% white, 10% Hispanic, 16% Black, and 6% 
Asian, with equal numbers of boys and girls, in line with recent studies conducted in these settings. We 
will employ a method of enrolling subjects that has been evaluated and refined as part of our prior 
work. 
At CNMC, there are currently 614 active patients with T1D between the ages of 13-17 years, and there 
are no current competing studies within this age group. The adolescent patient population is 47% 
female and 52% Caucasian. Thus, CNMC is well-positioned to provide an adequate and diverse sampling 
of participants for the proposed study. 
At VUMC, there are currently 1100 active patients between the ages of 13-17, and the adolescent 
patient population is 48% female and 75% Caucasian. Thus, we do not anticipate difficulty in meeting 
our enrollment goals. 
We created recruitment videos to explain the study in a brief and engaging format:  
https://youtu.be/lQT4REEruoQ (VUMC); https://youtu.be/Uinw_a8_5Lo (CNH) 
We will also use Research Match and the Vanderbilt Research Notifications Distribution list to reach 
more potential VUMC participants. 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
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After completing visit 2 (3 month follow up data collection and exit interview) we will invite 20 youth 
participants who currently use/have used a CGM to participate in an optional interview to describe the 
role of CGM on their diabetes management. 
 Screening. We will screen adolescents for diabetes distress using a validated measure, the Problem 
Areas in Diabetes-Teens scale (PAID-T). In order to meet our enrollment goals, enrolling 4-5 per month 
per site, we will plan to screen 10-12 families per week. 
  
Retention & Follow-Up: Efforts will be made to maximize retention across trial assessments. These 
include providing study retention items (e.g., keychain flashlights, laptop decals with the study logo), 
sending birthday cards to trial participants, and verifying contact information, including email addresses 
and phone numbers, at each assessment point. As in previous studies, we will attempt to collect follow-
up data in person during regularly scheduled clinic appointments. Prior to their scheduled appointment, 
families will be reminded of the visit and asked to come early or stay after their appointment. If families 
cancel or do not show for their appointments, we will email and text a unique link to the REDCap survey 
and continue to follow up by phone and email until surveys are completed. We will give the family the 
option of doing a Coremedica HemaSpot-SE HbA1c kit at home if they are unable to come into the clinic 
to get a point of care A1c test. If families are not responsive, we will send a paper packet with a self-
addressed, stamped envelope. These methods have resulted in excellent retention rates (91-98%) in our 
pilot studies. We will actively work towards maintaining families’ participation in data collection 
regardless of their engagement in the text messages so that intent-to-treat analyses may be conducted. 
We are conservatively planning for a ~15% attrition rate based on data from our pilot studies to protect 
against overestimation. 
  
Incentives. In order to promote the completion of trial measures at all assessment points, participants 
will be compensated for their time at each data collection, with increasing compensation ($20, $25, $30, 
$30) to improve retention. In addition, participants will receive $10 for participating in a qualitative exit 
interview at the 3-month data collection. Participants who complete the secondary study (interview 
describing their CGM use) will receive an additional $30 gift card. 
 

Thrive! Positive Psychology Intervention to Treat Diabetes Distress in Teens with Type 1 
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6 STUDY INTERVENTION(S) OR EXPERIMENTAL MANIPULATION(S) 
6.1 STUDY INTERVENTION(S) OR EXPERIMENTAL MANIPULATION(S) ADMINISTRATION 
Eligible families will be asked to stay after their appointment to complete enrollment, or they may 
choose to come back for a study visit. Trained study staff will describe the study in detail to interested 
families. They will be encouraged to ask questions before giving consent. After obtaining informed 
consent/assent, adolescents and parents will complete a battery of self-report measures (see below) 
and will be randomized to the Positive Affect plus Education texting condition (TXT) or the Education 
only condition (EDU). Adolescents and parents will complete measures again 3 months, 6 months, and 
12 months during regularly scheduled clinic visits. 
  
Adolescents and their parents will complete measures on a tablet using REDCap, an electronic database. 
The survey completion is expected to take 30 minutes. 
After completing baseline data, adolescents will be randomized to either the Education group or the 
text-messaging Positive Affect + Education group (TXT).  
  
6.1.1 Study Intervention or Experimental Manipulation Description 
Participants randomized to the EDU group will complete a behavioral health contract. The health 
behavior contract states the behavior that they are committing to do (e.g., check blood glucose 4 
times/day), when they will do it (e.g., before meals and before bedtime), and how often they will 
perform the target behavior (e.g., daily). They will also receive a 14-page educational packet, with age-
appropriate information from the American Diabetes Association website on the following topics: 
understanding A1C, driving and diabetes, hyper- and hypoglycemia, and sports and exercise. 
  
Participants randomized to the TXT group will complete a behavioral health contract. They will also 
receive an educational packet, with age-appropriate information from the American Diabetes 
Association website (e.g., understanding A1C, driving and diabetes). Adolescents in the TXT group will 
also complete a positive affect interview at baseline with a trained research assistant. During the 
positive affect interview, adolescents will be asked to list three things that make them feel good, even 
for just a few minutes. Next, they will be asked to choose two to three values that they personally found 
to be most important from the following list: Enjoying Sports, Art, Working Hard in School, Having a 
Sense of Humor, Being Creative, Belonging to a Social Group or Club, Following Politics or Current 
Events, Relationships with Friends, Relationships with Family, Faith or Spirituality, Music. The 
adolescents will write a few short sentences about why those values are important to them, and to 
provide an example of a time they accomplished something or had a good experience related to that 
value. Further, parents will be asked to provide positive affirmations (praise or positive messages) to 
their adolescents, focused on non-diabetes strengths. Parents will be given examples of messages and 
asked to write a sample positive message. The trained research assistant will give parents feedback on 
their messages to ensure that they meet the requirements. 
  

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Version 7
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A brief assessment of positive affect (Positive and Negative Affect Scale -- Child -- Short Form), consisting 
of 10 items, will be obtained from all adolescents via automated text messaging twice/month during the 
8-week intervention. All adolescents will also be sent a retention item (e.g., laptop decal) halfway 
through the 8-week intervention period. 
  
Follow-up data (self-report measures and clinical data) will be collected at 3 months, 6 months, and 12 
months after enrollment in REDCap. In addition, teens and parents will be invited to participate in an 
exit interview at the 3-month follow-up data collection. 
 
After completing the exit interview participants who currently use or have used a CGM will be offered 
the opportunity to participate in a secondary study to understand how adolescents use CGM to manage 
their diabetes. This will be a 1 time zoom interview that lasts approximately 45 minutes. 
 
6.1.2 Administration and/or Dosing 
Adolescents in the TXT group will receive automated text messages 5 days/week for 8 weeks. Messages 
will be tailored to include adolescents’ responses to the baseline interview, including reminders to 
engage in gratitude and self-affirmation. Gratitude messages (e.g., "Last week you said [response from 
gratitude exercise] made you happy. Have you noticed that this week, even for a few minutes?") will be 
sent once/week. Important value messages (e.g., "You mentioned that [response from values exercise] 
was important to you, and I asked you to think about that when it was hard for you to check your blood 
sugar. Have you done that this week?") will be sent once/week. Mood Booster messages will be sent 2-3 
times/week. Mood Boosters include inspirational messages (e.g., "Believe you can, and you’re halfway 
there!") and humorous messages (e.g., "Which hand is it better to write with? A: Neither, it’s best to 
write with a pen!"), based on earlier work to obtain teens’ ratings of messages. Younger teens (age 13-
14) will receive some different messages than older teens (age 15-17), based on ratings.  Additionally, to 
induce positive mood, teens will be texted gift cards codes valued at $5.00 on alternating weeks. Parents 
will receive weekly text message reminders to provide positive messages to their teens. 
6.2 FIDELITY 
6.2.1 INTERVENTIONIST TRAINING AND TRACKING 
Trained Key Study Personnel will administer the health behavior contract and conduct the positive affect 
interview. 
 
 
6.3 MEASURES TO MINIMIZE BIAS: RANDOMIZATION AND BLINDING 
The randomization scheme will be determined by the biostatistician, and adolescents will be stratified 
by diabetes device use (insulin pumps, continuous glucose monitors). 
 

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7.1 DISCONTINUATION OF STUDY INTERVENTION/EXPERIMENTAL MANIPULATION 
If participants ask to be withdrawn from the study, the reason(s) for discontinuing the participant from 
the intervention, and methods for determining the need to discontinue will be documented in the study 
record. 
 
7.2 PARTICIPANT DISCONTINUATION/WITHDRAWAL FROM THE STUDY 
Participants are free to withdraw from participation in the study at any time upon request. 
An investigator may discontinue a participant from the study for the following reasons: 
• 
Significant study intervention non-compliance 
• 
Lost-to-follow up; unable to contact subject 
• 
Any event or medical condition or situation occurs such that continued collection of follow-up 
study data would not be in the best interest of the participant or might require an additional 
treatment that would confound the interpretation of the study 
• 
The participant meets an exclusion criterion (either newly developed or not previously 
recognized) that precludes further study participation 
The reason for participant discontinuation or withdrawal from the study will be recorded in the REDCap 
database. Subjects who sign the informed consent form and are randomized but do not receive the 
study intervention may be replaced.  Subjects who sign the informed consent form, and are randomized 
and receive the study intervention, and subsequently withdraw, or are discontinued from the study, will 
not be replaced. 
 
 
7.3 LOST TO FOLLOW-UP 
A participant will be considered lost to follow-up if he or she fails to return for 2 scheduled visits and 
study staff are unable to contact the participant after at least 3 attempts. 
The following actions must be taken if a participant fails to return to the clinic for a required study visit: 
• 
The site will attempt to contact the participant, reschedule the missed visit within 2 weeks, 
counsel the participant on the importance of maintaining the assigned visit schedule and 
ascertain if the participant wishes to and/or should continue in the study 
• 
Before a participant is deemed lost to follow-up, the investigator or designee will make every 
effort to regain contact with the participant (where possible, 3 telephone calls and text 
messages and, if necessary, a certified letter to the participant’s last known mailing address or 
local equivalent methods). These contact attempts will be documented in the participant’s 
medical record or study file. 

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• 
Should the participant continue to be unreachable, he or she will be considered to have 
withdrawn from the study with a primary reason of lost to follow-up 

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8 STUDY ASSESSMENTS AND PROCEDURES 
8.1 ENDPOINT AND OTHER NON-SAFETY ASSESSMENTS 
 
Follow-up data will be collected at 3 months, 6 months, and 12 months. 
8.2 SAFETY ASSESSMENTS 
n/a 
 
8.3 ADVERSE EVENTS AND SERIOUS ADVERSE EVENTS 
8.3.1 DEFINITION OF ADVERSE EVENTS 
This protocol uses the definition of adverse event from 21 CFR 312.32 (a): any untoward medical 
occurrence associated with the use of an intervention in humans, whether or not considered 
intervention-related. 
  
8.3.3.1 SEVERITY OF EVENT 
For adverse events (AEs) not included in the protocol defined grading system, the following guidelines 
will be used to describe severity. 
• 
Mild: Events require minimal or no treatment and do not interfere with the participant’s daily 
activities. 
• 
Moderate: Events result in a low level of inconvenience or concern with the therapeutic 
measures. Moderate events may cause some interference with functioning. 
• 
Severe: Events interrupt a participant’s usual daily activity and may require systemic drug 
therapy or other treatment. Severe events are usually potentially life-threatening or 
incapacitating. 
  
  
8.3.2 ADVERSE EVENT REPORTING 
The PI will be responsible for reporting AEs according to policies and procedures. 
  

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9 STATISTICAL CONSIDERATIONS 
9.1 STATISTICAL HYPOTHESES 
• 
Primary Efficacy Endpoint(s): 
The primary outcome is change in glycemic control (A1C). To test Aim 1, a linear mixed effects 
regression model will be used to estimate the effect of intervention over time on glycemic control (A1C). 
• 
Secondary Efficacy Endpoint(s): 
Our secondary outcomes are diabetes distress, coping, and diabetes management. To test Aim 2, 
separate linear mixed effects regression models will be used to estimate the effect of the intervention 
over time on diabetes distress (PAID-T), coping (RSQ), and diabetes management (P-SCI, SCI, 
Checks/Day). Qualitative methods will be used to code data from the secondary CGM interview study 
into appropriate themes that then guide analysis. 
 
 
9.2 SAMPLE SIZE DETERMINATION 
Power Analysis: We plan to enroll 200 adolescent-parent dyads and conservatively assume a 15% 
dropout rate, leaving 170 subjects for analysis.  Power calculations for the repeated-measures design 
were conducted using a variety of statistical simulations for each of the outcomes.  Inputs into the 
simulation study, based on preliminary data from 46 subjects measured 3 months apart, were baseline 
mean, baseline standard deviation, and correlation between baseline and 3-month measurement. Table 
3 summarizes the effect sizes that we will have at least 90% power to detect at a 0.05 significance level. 
  
  
9.3 STATISTICAL ANALYSES 
9.3.1 General Approach 
Outcomes will be measured at up to four time-points per subject (baseline, 3 months, 6 months, and 12 
months), so we will use time, treatment group and the interaction of treatment with time serving as the 
main explanatory variables.  Such a model will allow us to test for any differences between treatment 
and control groups at 3, 6 or 12 months while accounting for baseline values. While the randomized 
block design should minimize confounding, we will adjust for age, sex, and race/ethnicity to improve 
precision.  The results from the adjusted and unadjusted models will be compared with respect to their 
estimates of the treatment effects. We will include a random intercept to account for within-subject 
correlation arising from taking repeated measurements on the same subject over time. The error 
structure of the model is assumed to be compound symmetric, and the validity of this assumption will 
be examined by computing Akaike Information Criteria against other common structures.  Subjects will 

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be included in the analysis if they have an outcome measured at baseline and at least one outcome 
measured at 3, 6 or 12 months. 
 9.3.2 Exploratory Analyses 
Exploratory Aim: To examine the differential impact of intervention effects across demographic (i.e., 
age, race/ethnicity, sex) and treatment variables (i.e., diabetes devices), we will examine these factors 
as potential moderators of the intervention effects. 
Power to detect if the treatment effect is modified by age, sex, race, or treatment type will depend on 
the frequency of these factors in the sample. In pilot data, we found the frequencies to be 50% male, 
60% pump treatment type, and 67% white (EA), and for age we present result where age is 
dichotomized at its median. 
  
The size of the effect modification that we can detect with 80% power for each outcome and effect 
modifier is presented in the following table.  The detectable effect sizes for effect modification at 80% 
power are similar to the effect sizes for the treatment at 90% power. The effect modification power 
table assumes 200 subjects with 15% dropout (170 subjects analyzed) and a significance level of 0.05.