Dyspnea, cough, and chronic mucus hypersecretion are common symptoms in patients with Chronic Obstructive Pulmonary Disease (COPD), which increases risk of infections followed by exacerbations, often leading to hospitalization, disease progression and mortality. This patient group requires lifelong treatment in healthcare. A mobile application was developed to facilitate adherence to evidence-based guidelines for tailored breathing and airway clearance techniques to enhance self-management. The app is only in Norwegian and has a Norwegian name which is "Pust Deg Bedre" (PDB). The PDB app is fully developed and tested and can be downloaded for free. The app seems promising as a treatment tool, but has not yet been clinical evaluated. This project aims to 1) explore the feasibility of providing the app for patients with COPD, 2) explore the patients' with COPD experiences with the use of the PDB-app in treating dyspnea and mucus secretion, 3) explore the physiotherapists' experiences with the use of the PDB-app in treating dyspnea and mucus secretion, 4) explore the physiotherapists' experiences with implementing the PDB-app in treatment of patients with COPD, 5) explore the patients' experiences with the education in use of the PDB-app, and 6) At a 6-month follow up: explore the physiotherapists experiences with the usefulness and applicability of PBD-app, and to generally explore their experiences with participating in the project.

This project is designed to explore aspects of acceptability and possible uncertainties associated with implementing the PDB-app as part of self-management in patients with COPD. Both quantitative and qualitative data will be collected and analysed.

50-60 patients with COPD and 15-30 physiotherapists in primary health care will be recruited.

A feasibility study will be conducted and evaluated after 8-week intervention and at 6-month follow-up, using a pre-post design.

Intervention: The physiotherapists will be responsible for providing the patients with training on the use of the PDB-app. Based on clinical assessment, the patients will receive a tailored treatment plan within the app. Patients are expected to engage with the tailored PDB-treatment for 8 weeks with follow-up after 6 months. If necessarily, adjustments to the treatment plan will be made throughout the intervention period. Follow-up of patients will occur digitally and physically.

A qualitative interview study will be conducted with semi-structured interviews after 8 weeks of intervention for a deeper understanding of the patients' and physiotherapists' experiences with the PDB-app. Separate focus groups will be conducted with the patients and the physiotherapists.

The investigators will also conduct video-recorded physiotherapy sessions at two time points during the intervention. The first one during the initial session, and then again between 3 to 6 weeks during the 8-week intervention. Subsequently, in-depth interviews, using Interpersonal Process Recall (IPR), will be conducted, with the researcher and physiotherapist, and with the researcher and patient. By using IPR interviews, video-assisted recall will help research participants access underlying experiences of their recent clinical interactions and put them into words. This means that the interaction between patient, physiotherapist and the PDB-app, experienced and recalled in the interview, relates to concrete events of the specific session.

Targeting physiotherapists, the investigators aim to do a long-term follow up 6 months after the intervention and explore their experiences with having participated in IPR interviews and as participants in the study in general. How and to what degree has the IPR interview sessions and the experiences from participating in this project impacted on their clinical practice, perception of role, identity and lifeworld? The investigators will conduct individual semi-structured qualitative interviews with all the physiotherapists from the IPR interviews.

Criteria for success:

• At least 80% of the patients complete the intervention and the questionnaires after 8-weeks
• At least 80% of the patients' complete questionnaires at 6-month follow-up
• At least 90% of physiotherapists complete the study period
• No adverse events by using the PDB-app
• Patient satisfaction score measured with CSQ-8 ≥20 (indicate good satisfaction)

Inclusion Criteria:

• Clinical diagnosis of Chronic Obstructive Pulmonary Disease
• Mucus-related issues ≥3 times per week
• Speak and write Norwegian
• Ability to independently operate a smartphone and/or iPad

Exclusion Criteria:

• Severe mental illness
• Substance abuse that hinder participation in the study

In accordance with the approvals granted for this study by the Regional Committee on Medical Research Ethics and the Norwegian Data Inspectorate, the data files will be stored securely and in accordance with the Norwegian Law of Privacy Protection. A subset of the data file with anonymized data will be made available to interested researchers upon reasonable request to Bente Frisk: bente.frisk@hvl.no, providing that Norwegian privacy legislation and the General Data Protection Regulation are respected, and that permission is granted from the Norwegian Data Inspectorate and the data protection officer at Western Norway University of Applied Sciences.

Will be available after data completion of the study: 31.12.30

In accordance with the approvals granted for this study by the Regional Committee on Medical Research Ethics and the Norwegian Data Inspectorate, the data files will be stored securely and in accordance with the Norwegian Law of Privacy Protection. A subset of the data file with anonymized data will be made available to interested researchers upon reasonable request to Bente Frisk: bente.frisk@hvl.no, providing that Norwegian privacy legislation and the General Data Protection Regulation are respected, and that permission is granted from the Norwegian Data Inspectorate and the data protection officer at Western Norway University of Applied Sciences.