This clinical study examines whether a co-designed mobility intervention can be delivered in routine hospital care after hip fracture surgery.

Hip fracture is a common and serious condition among older adults and is associated with loss of independence, complications, and increased mortality. During hospitalization, many patients remain inactive, even though early and frequent mobility is considered important for recovery.

The HIP-ME-UP intervention was developed in collaboration with healthcare professionals, patients, caregivers, and hospital management. It aims to support early mobilization, independence in basic mobility activities such as getting in and out of bed and increased physical activity during hospitalization.

The study will investigate whether the intervention is feasible to deliver in routine clinical practice, whether it is delivered as intended, and whether it is acceptable to patients and healthcare professionals.

Participants admitted after a hip fracture surgery will receive the intervention during hospitalization. Researchers will collect information on recruitment, retention, fidelity, acceptability, and mobility-related outcomes. Approximately 25 participants will be included.

The results will help determine whether a larger effectiveness study should be conducted.

This study evaluates the feasibility, fidelity, and acceptability of a co-designed intervention developed within the HIP-ME-UP research program to promote early and frequent mobility among older adults hospitalized after hip fracture surgery.

Despite clinical recommendations for early mobilization, patients with hip fracture are often inactive during hospitalization, which may negatively impact recovery. The intervention was developed in collaboration with healthcare professionals, management, patients, and caregivers to address this gap.

The HIP-ME-UP intervention consists of four components:

1. A dedicated porter supporting physiotherapy and occupational therapy mobility activities
2. A standardized training concept to promote independence in getting in and out of bed
3. Group-based exercise supervised by physiotherapists
4. Personal activities of daily living (P-ADL) performed in the bathroom when feasible

The study uses a single-site, single-group feasibility design and will be conducted over an approximately 8-week period in orthopedic wards at Copenhagen University Hospital Hvidovre.

The primary aim is to assess whether the intervention can be delivered as intended in routine clinical practice. Feasibility outcomes include recruitment, retention, and data completeness. Fidelity will be assessed in terms of adherence to intervention content, dose, frequency, and quality of delivery. Acceptability will be explored through interviews and questionnaire responses among patients and healthcare professionals.

Clinical and functional outcomes, including mobility, physical activity, pain, and health-related quality of life, will be collected descriptively to support interpretation of feasibility findings and potential mechanisms of impact.

Feasibility will be evaluated using predefined progression criteria focusing on recruitment, retention, fidelity, and acceptability. These criteria will be interpreted using a traffic-light approach categorizing results as "stop", "amend", or "go". Progression decisions will be based on an integrated assessment of quantitative feasibility outcomes together with qualitative process data describing barriers, facilitators, and adaptations during implementation.

The findings will be reviewed by the HIP-ME-UP research group and steering committee to determine whether the intervention and trial procedures are sufficiently feasible to proceed to a future large-scale randomized effectiveness trial. The study is not designed to evaluate clinical effectiveness.

The study applies a feasibility-oriented outcome framework without hierarchical prioritization of outcomes. Feasibility, fidelity, acceptability, process data, and descriptive clinical outcomes are assessed in parallel, each contributing equally to a comprehensive evaluation of whether and how the HIP-ME-UP intervention can be delivered in routine clinical practice.

The study was assessed by the Regional Commitee on Health Research Ethics of the Capital Region of Denmark with journal no. H-26006578.

Inclusion Criteria:

• Age ≥ 60 years.
• Admitted to one of the two acute orthopedic wards at Copenhagen University Hospital Hvidovre (CUHH) following hip fracture surgery.
• Pre-fracture Cumulated Ambulation Score (CAS) (by recall) ≥ 3 points, indicating independence or assisted independence in basic mobility activities such as bed transfer, chair transfer, and indoor walking.
• Participants may be included if they are able to provide informed consent independently or if informed consent is obtained from a legally authorized proxy (e.g., caregiver or close relative) in cases of cognitive impairment. This applies to both Danish- and non-Danish speaking patients. Non-Danish speakers may be included with support from translated study materials and assistance from relatives or interpreters, where appropriate.
• Inclusion the latest on postoperative day three.

Exclusion Criteria:

• Non-ambulatory before the fracture, e.g. permanently bedbound or wheelchair-dependent.
• Terminal illness with limited expected survival.
• Post-operative weight-bearing restrictions precluding mobility activities.
• Multiple fractures or suspected pathological fractures (e.g. related to malignancy).
• Clinically unstable or presenting conditions in which early mobilization is contraindicated.
• Patients who previously participated in HIP-ME-UP Study 4, ensuring that recipients in Study 6 have not been prior HIP-ME-UP study participants or patient partners.

Due to Danish data protection legislation, individual participant data cannot be publicly shared. Access to pseudonymized data may be granted upon reasonable request and approval by the Danish Data Protection Agency.