Eating Disorder Dynamic Intervention

BEHAVIORAL

Eating Disorder Dynamic Intervention

Participants will use a smartphone-based program designed to support eating disorder recovery in daily life. Participants will complete brief surveys about their mood, thoughts, and behaviors, and the smartphone will also passively collect activity-related data. This information is used to detect times when a person may be at higher risk for eating disorder behaviors. Participants will watch 4 video modules that introduce the core enhanced cognitive-behavioral therapy skills for eating disorders (reducing dietary restraint, urge management, emotion regulation, and improving body image), provide rationale, and prompt participants to complete interactive activities to practice these skills. Participants will then receive micro-randomized JITAIs prompting them to use these skills in their daily lives; micro-randomization will be used to deliver a JITAI from one of the 4 skill categories (reducing dietary restraint, urge management, emotion regulation, improving body image) or no JITAI.

Area under the receiver operating curve (AUC)

Time frame: Weeks 5 and 6 of data collection

Performance of the eating disorder behavior prediction models will be evaluated by computing the area under the receiver operating curve (AUC) for each participants' models on two-weeks of held out (test) data (collected during weeks 5 and 6 of the data collection procedure). The AUC can take on values between 0 and 1, with higher values indicating superior model performance.

Brier Score

Time frame: Weeks 5 and 6 of data collection

Performance of the eating disorder behavior prediction models will be evaluated by computing the Brier score for each participants' models on two-weeks of held out (test) data (collected during weeks 5 and 6 of the data collection procedure). The Brier score can range from 0 to 1 with lower values indicating less model error (i.e., better model performance).

Binge eating

Time frame: Weeks 7 through 16 of data collection

Binge eating occurrence during the data collection protocol will be measured. Binge eating at each ecological momentary assessment survey will be assessed by the question, "Thinking about your most recent eating episode, did you experience loss of control?" (Answer choices = Yes or No).

Dietary restriction

Time frame: Weeks 7 through 16 of data collection

Dietary restriction will be measured during the data collection protocol. Dietary restriction will be assessed at each ecological momentary assessment survey by the questions, "Thinking about your most recent eating episode, did you limit the amount of food you ate to influence your shape?", "Thinking about your most recent eating episode, did you exclude specific foods to influence your shape or weight?", and Since the last survey, have you skipped a meal or snack?" (Answer Choices = Yes or No).

Compensatory behaviors

Time frame: Weeks 7 through 16 of data collection

Dietary restriction will be measured during the data collection protocol. Dietary restriction will be assessed at each ecological momentary assessment survey by the questions, "Since the last survey, have you engaged in any of the following? Self-induced vomiting," "Laxative use (to influence shape or weight)," "Diuretic use (to influence shape or weight)," "Diet pill use (to influence shape or weight)," "Exercise (to influence shape or weight)," and "Other behavior to influence shape or weight" (Answer Choices = Yes or No).

Feasibility and Acceptability Questionnaire

Time frame: End of study assessment (after week 16 of data collection)

Acceptability will be evaluated via the Feasibility and Acceptability Questionnaire. These data will be collected after participants have completed the 16 weeks of data collection using the EDDI app. Mean ratings ≥ 5 (on the seven-point Likert rating scales) on acceptability items will be considered to indicate acceptability. The response scale is as follows: 1=Strongly Disagree 2=Disagree 3=Disagree a little 4=Neither agree nor disagree 5=Agree a little 6=Agree 7=Strongly Agree, with higher scores indicating greater acceptability.

System Usability Scale

Time frame: End of study assessment (after week 16 of data collection)

Acceptability will be evaluated via the System Usability Scale. These data will be collected after participants have completed the 16 weeks of data collection using the EDDI app. Mean ratings ≥ 4 (on the five-point Likert rating scale) on System Usability Scale items will be considered to indicate acceptability. The response scale runs from 1 = Strongly Disagree (minimum value) to 5 = Strongly Agree (maximum value), with higher ratings indicating greater usability. Items 2, 4, 6, 8, and 10 will be reverse coded to align with higher ratings indicating greater usability.

Percentage of Eligible Participants Enrolled

Time frame: Through study completion, an average of 4 months

Feasibility of the EDDI app will be evaluated by computing the percentage of eligible participants enrolled. This will be computed by dividing the number of enrolled participants by the total number of eligible participants and multiplying by 100. At least 85% of eligible participants enrolled will be considered to demonstrate feasibility.

Attrition Rate

Time frame: Through study completion, an average of 4 months

Feasibility of the EDDI app will be evaluated by computing the attrition (drop out) rate. This will be computed by dividing the number of participants who discontinue the study prior to the end of study assessment by the total number of enrolled participants and multiplying by 100. An attrition rate of less than 15% will be considered to demonstrate feasibility.

Percentage of JITAIs Producing Skill Use

Time frame: Through study completion, an average of 4 months

Feasibility of the EDDI app will be evaluated by computing the percentage of JITAIs that produce participant-reported skill use. This will be computed by dividing the instances of reported skills used by the total number of delivered JITAIs and multiplying by 100. JITAIs producing skill use at least 80% of the time will be considered to demonstrate feasibility.

What is a clinical trial?

A clinical trial is a research study that tests new medical treatments, drugs, devices, or procedures to determine their safety and effectiveness. Trials are carefully designed and monitored to protect participants while advancing medical knowledge.

Is it safe to participate?

Clinical trials follow strict safety guidelines and ethical standards. Trials must be reviewed and approved, and participants are closely monitored by medical professionals throughout the study. You can withdraw at any time if you choose.

Will I be compensated?

Many clinical trials offer compensation for your time, travel expenses, and inconvenience. The specific compensation varies by study and will be discussed during the screening process. All study-related medical care is typically provided at no cost to participants.

Will I receive a placebo instead of treatment?

When effective treatment exists, participants typically receive either the standard treatment plus the study intervention, or the standard treatment plus placebo. You would not be denied effective care. Placebos are primarily used when no proven treatment is available, or in addition to standard care. Your trial consent form will clearly explain what treatments you may receive.

Can I leave a trial if I change my mind?

Absolutely. Participation in clinical trials is completely voluntary. You have the right to withdraw from the study at any time, for any reason, without penalty or loss of benefits to which you are otherwise entitled.

How long does a clinical trial last?

Trial duration varies widely depending on the study design and purpose. Some trials last just a few weeks, while others may continue for months or years. The study coordinator will provide specific timeline information during your screening call.