Feasibility of a Well-being Promotion Self-management Intervention in Post-COVID-19 Patients

Feasibility is assessed using items asking how often exercises were executed (never, 1, 2 or 3 times).

Acceptability is assessed using items on willingness to do again, satisfaction, perceived utility, experienced ease-of-use, experienced discomfort, and willingness to recommend to a) other patients and b) friends. Each item is measured on 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and assessed on an item level.

Acceptability is assessed using items on willingness to do again, satisfaction, perceived utility, experienced ease-of-use, experienced discomfort, and willingness to recommend to a) other patients and b) friends. Each item is measured on 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and assessed on an item level.

Acceptability is assessed using items on willingness to do again, satisfaction, perceived utility, experienced ease-of-use, experienced discomfort, and willingness to recommend to a) other patients and b) friends. Each item is measured on 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and assessed on an item level.

Acceptability is assessed using items on willingness to do again, satisfaction, perceived utility, experienced ease-of-use, experienced discomfort, and willingness to recommend to a) other patients and b) friends. Each item is measured on 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and assessed on an item level.

Acceptability is assessed using items on willingness to do again, satisfaction, perceived utility, experienced ease-of-use, experienced discomfort, and willingness to recommend to a) other patients and b) friends. Each item is measured on 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and assessed on an item level.

Acceptability is assessed using items on willingness to do again, satisfaction, perceived utility, experienced ease-of-use, experienced discomfort, and willingness to recommend to a) other patients and b) friends. Each item is measured on 5-point Likert scale from 1 (strongly disagree) to 5 (strongly agree), and assessed on an item level.

Acceptability will be further explored via in-depth interviews (optional in addition to the post- and follow-up questionnaires) and assessed using thematic analysis

Measured with the 20-item Positive and Negative Affect Schedule (PANAS). Positive affect (10 items) and negative affect (10 items) are assessed on a scale from 1 (not at all) to 5 (extremely) and calculated as sum scores. Higher scores indicate larger levels of positive and negative affect.

Measured with the 14-item Mental Health Continuum short form (MHC-SF), which assesses three subscales (emotional well-being via 3 items; psychological well-being via six items; and social well-being via five items) and a total mental well-being scale. Mean scores range between 0 - 5, with higher scores indicating more well-being.

Measured with the modified COVID-19 Yorkshire Rehabilitation Scale (C19YRSm) resulting in four subscales: symptom severity (0 - 30; higher scores indicating higher severity); functional ability (0 - 15; higher scores indicating higher dysfunction); presence of other symptoms (0 - 25; higher scores indicating more symptoms); and self-reported general health (0 - 10; higher scores indicating better health).

Measured with the 4-item Short Fatigue Questionnaire (SFQ), resulting in one sum score of 4 - 28. Higher scores indicate more severe fatigue with scores ≥18 signalling clinically severe fatigue.

Measured with the 14-item Hospital Anxiety and Depression Scale (HADS), with one subscale (7 items) on anxiety and one subscale (7 items) on depression. Sum scores range between 0 - 21 with higher scores (>7) indicating higher severity.

Measured with the 14-item Hospital Anxiety and Depression Scale (HADS), with one subscale (7 items) on anxiety and one subscale (7 items) on depression. Sum scores range between 0 - 21 with higher scores (>7) indicating higher severity.

Ability to adapt is measured with the 10-item Generic Sense of Ability of Adapt Scale (GSAAS), resulting in a mean score between 0 - 4; higher scores indicating better sense of adaptability.

Illness perceptions, including perceived illness control and perceived treatment control, are measured with the brief Illness Perception Questionnaire (IPQ-K). Items are scored on range from 0 - 10, for control items higher scores indicating better perceived control.

Perceived impact of the intervention will be explored via in-depth interviews (optional in addition to the post- and follow-up questionnaires).

Recommendations for future interventions or iterations, including strengths of the training and motivation to participate, will be explored via in-depth interviews (optional in addition to the post- and follow-up questionnaires).