The goal of this clinical trial is to investigate whether pre- and postoperative treatment with systematic PEP therapy can prevent hospital-acquired pneumonia in patients with hip frac-ture. It will also learn about the barriers regarding PEP therapy in this group of patients.

• Does pre- and postoperative treatment with systematic PEP therapy prevent hospital-acquired pneumonia in patients with hip fracture?
• Which barriers do participants have regarding PEP therapy in this group of patients? Researchers will compare systematic PEP therapy to no intervention besides standard treat-ment to see if systematic therapy with PEP can prevent hospital-acquired pneumonia.

Participants will:

• Receive systematic PEP therapy during hospitalization or no intervention besides standard treatment
• Register the PEP therapy four times daily on a paper checklist. Failure to perform the treatment and the reason must also be documented on the checklist.

Inclusion Criteria:

• Hip fracture regardless of age
• Cognitively well-functioning
• Able to understand the study and give informed consent
• Able to speak and understand Danish
• Resident of Region Hovedstaden or Region Sjælland

Exclusion Criteria:

• Cognitively impaired
• Unable to understand the study and give informed consent
• Pneumonia upon admission
• Delirium upon admission
• Pneumothorax

For patients with e.g. dementia or brain injury, the ability to give informed consent will be assessed individually.

Access to individual de-identified participant data and related study documents (e.g. protocol, Statistical Analysis Plan (SAP), will be provided to anyone who wishes to access the data.