Short summary

Patient reported outcome measures (PROMs) are used to assess hip function from the patients' point of view. The project will give an assessment whether the PROMs existing today are reflecting patients' way of assessing hip-function. This will clarify if there is a need for developing a new and more patient-representative PROM. Furthermore, the project will assess which PROM is the most ideal for use in relation to the time of treatment. This project, focusing on involvement of patients undergoing total hip arthroplasty, will be performed as a qualitative project with focus group interviews. 

Rationale

Osteoarthritis (OA) is the leading cause of pain and disability worldwide. Pain and functional disability are two acknowledged indicators for primary total hip arthroplasty (THA), in patients with moderate to severe arthritis of the hip. THA is a common surgical procedure, which relieves pain and improves function and quality of life.
Traditional rating systems assessing the outcome after THA frequently focus on surgeons and health care professionals' objective measurements. However, patient-reported outcome measures (PROMs) are increasingly used as an indicator of the outcome and for evaluation of the patients' quality of life.

A number of disease- and joint-specific PROMs have been developed for use with orthopaedic conditions. There is often no consensus as to which scores that should be used. The PROMs that exist today mainly focus on the patients' function in typical activities of daily living, pain or joint stiffness, and is not entirely based on factors that patients themselves have contributed with. Commonly used PROMs for patients suffering from OA of the hip and evaluation of THA are the Hip disability and Osteoarthritis Outcome Score (HOOS), the Oxford Hip Score (OHS) and the Forgotten Joint Score (FJS).

The HOOS is an adaptation of the Knee injury and Osteoarthritis Outcome Score (KOOS).
KOOS, is a further development of the Western Ontario and Macmaster Universities Osteoarthritis index (WOMAC). The items from WOMAC were constructed in a study where a survey questionnaire was developed in a process involving four academic rheumatologists and two clinical epidemiologists, and questions were also derived from six existing questionnaires.

The items from KOOS were constructed on the basis of a literature review, an expert panel comprised of patients referred to physical therapy as well as orthopaedic surgeons and physical therapists, and a pilot study where factors among patients with posttraumatic osteoarthritis were identified. The expert panel contributed with identifying short- and long-term symptoms and functional disabilities. Five additional items were added to HOOS, which was constructed by one of the authors using material from patient interviews.

The OHS was developed by interviewing 20 patients to identify how they experienced and reported problems with their hips. After reviewing other established questionnaires, a list of 20 items was drafted, and then given to 20 other patients. Hereafter, the list was reviewed again and modified to make items more reproducible and easier to understand. Further, the questionnaire was tested in two additional series until the final version was agreed.

The FJS was developed based on literature research and expert opinion choosing items relevant to the average population undergoing THA and total knee arthroplasty. The team of experts was comprised of clinicians, a methodologist and a statistician. In addition, patients' opinion were assessed to identify the activities of daily living that are important to a population undergoing arthroplasty.

Patient involvement ensures that PROMs will reflect the patients' standpoints. However, it is generally not well defined how much patients have been involved in making the PROMs.
There is also no consensus to which PROM should be used to which time according to the surgery, and not all PROMs may be representative for all phases of a surgical course.

The motivation to carry out this study is that even though the process of making the items are described in the development of the three commonly used PROMs, it remains quite unclear how the patient involvement was incorporated in the process of development.

Therefore, we decided to conduct a study to examine to which extend the items of the three commonly used PROMs are representative when comparing to factors patients themselves find relevant.
Furthermore, the project will assess which PROM is the most ideal for use in relation to the time of treatment.

Description of the cohort

Patients undergoing total hip arthroplasty from Orthopaedic departments of Odense University Hospital and Lillebaelt Hospital, Vejle; aged 60-75 years and diagnosed with primary osteoarthritis can be included in this study. The selection of patients with primary osteoarthritis is made because this group of patients comprises approximately 80% of patients undergoing primary THA.
The cohort will be fifty-fifty men and women. The patients are recruited according to three different periods in relation to time of treatment.

Data and biological material

One cohort will take part in focus group interviews with open-ended questions. After the interview, they will fill in three existing PROMs. Another cohort will fill in the same three PROMs as the first cohort. Data from the interviews will be the primary data. 

Collaborating researchers and departments

Department of Orthopaedic Surgery, Odense University Hospital

• Main supervisor professor Søren Overgaard, head of research, MD
• Primary investigator Camilla Holmenlund, stud.med

Department of Orthopaedic Surgery, Lillebaelt Hospital, Vejle

• Co-supervisor Claus Varnum, MD, PhD

Department of Clinical Research, Unit of Clinical Alcohol Research, University of Southern Denmark

• Co-supervisor assistant professor Randi Bilberg, PhD