Breathwork App for Cancer Survivors

Adherence will be evaluated by assessing total practice times by length in minutes.

Adherence is assessed by quantifying the number of completed app-based practice sessions relative to the total number of available sessions over 12 weeks.

Each practice session is defined as a 10-minute, app-timed exercise, automatically logged in the mobile application's backend (including both individual and group sessions).

Adherence is operationalized as:

Practice Frequency = total number of completed sessions Practice Proportion = completed sessions ÷ total possible sessions (180 sessions maximum; 3 sessions/day × 5 days/week × 12 weeks).

Both metrics are captured automatically by the app, which records each timed session as a completed practice.

Higher values indicate greater adherence.

Acceptability measures the participant's symptom management throughout the study duration. This is measured using The System Usability Scale (SUS) questionnaire, a 10 item questionnaire with 5 response options ranging from 'Strong Agree' to 'Strong Disagree'. The questionnaire will be administered at the end of 12 weeks to measure participants' acceptability of the study application. The acceptability is defined as a value of at least 68% in System Usability Scale. The values 0.6 and 0.2 represent 60% and 20% respectively. The higher percentage indicates greater system usability (meaning acceptability) of the app.

The Perceived Stress Scale-10 (PSS-10) is a validated 10-item questionnaire assessing perceived stress over the past month. Each item is scored 0-4, yielding a total score range of 0-40, where higher scores indicate greater perceived stress.

Scores are transformed into T-scores, standardized to a population mean of 50 with a standard deviation of 10.

Higher T-scores = worse stress Lower T-scores = improved stress The outcome reported is the change in T-score from baseline to Week 12, with negative values indicating improvement in perceived stress.

The use of T-scores supports comparison to normative samples and aligns with protocol-defined behavioral survey measures collected at Weeks 1 and 12.

Depression is measured using a validated 4-item Depression Scale with response options ranging from "Not at all" (0) to "Most of the time" (3). Total scores range from 0-12, with higher scores indicating worse depressive symptoms.

Scores are converted into standardized T-scores (mean 50, SD 10).

The outcome reflects the change in T-score from baseline to Week 12:

Negative change = reduction in depressive symptoms (improvement). Positive change = increased symptoms (worsening).

This description aligns with the protocol's Behavioral Survey Measures section, which includes depression assessed at Week 1 and Week 12.

The MD Anderson Symptom Inventory (MDASI) assesses 13 symptoms on a scale of 0-10, where 0 = no symptom and 10 = worst imaginable symptom.

The outcome is the change in mean symptom severity score from baseline (Week 1) to Week 12.

Negative values indicate improvement (reduction in symptom burden). Positive values indicate worsening (increase in symptom burden).

This aligns with the protocol, which identifies MDASI as a secondary behavioral survey measure collected at Weeks 1 and 12, with clinically meaningful changes defined as 0.5 SD differences.