Short summary

Despite improved pharmacological treatment for patients with Rheumatoid Arthritis (RA), footproblems are common, early as well as in the more advanced stages of the disease where foot deformities may occur. To measure the effect of an intervention aiming to improve foot problems, also patient reported outcome measures (PROMs) are needed. The self-reported foot and ankle score (SEFAS), is a valid and reliable score to assess foot problems before and after surgical interventions. The aim of this study was to assess the validity and reliability of the SEFAS in people with RA attending an outpatient clinic.

Rationale

Rheumatoid Arthritis (RA) is a chronic, systemic, inflammatory disease with an overall prevalence of RA reported in Nordic studies of approximately 0.5 % in the adult population. The onset of RA is often related to tenderness and swelling in the small joints and tendons of the hands and feet, and radiographic and MRI changes in the forefoot and functional foot disability are early findings. The peripheral joints are commonly involved in progression of the disease and synovitis may lead to pain, stiffness, joint destruction and deformity and altered foot mechanics affecting walking ability, quality of life and increase the risk for falls. Almost all patients with RA experience foot problems during the course of the disease. 

The introduction of biological agents have put a larger proportion of patients in remission and surgical procedures have decreased in the new millennium. However, as many as four out of ten patients in remission still report foot problems. In addition, 30 - 40% of all patients with RA do not respond to the new and effective treatments and foot problems may be an issue early as well as in the more advanced stages of RA where foot deformities may occur.  Assessment of foot problems should start in an early disease stage to prevent joint deformities and deterioration of foot function and a multidisciplinary approach is recommended.

To assess foot problems in the clinic, the sixty-eight-joint counts of painful and swollen joints has previously been used by the rheumatologist, but the modified composite disease activity score (DAS) including the twenty-eight-joint counts (DAS28) where the feet are left out, is the most common score used currently. Using DAS28 increases the risk for overlooking foot problems if the patients does not raise the issue themselves. 

There is a need for good and reliable outcome measures that assess foot problems in patients with RA at all disease stages suitable for the rheumatologists' joint assessment, as well as functional performance test, but also outcome measures that reflect the patients' view (patient reported outcome measures, PROMs). There are a number of PROMs developed to assess foot problems in patients with RA, and reviewing psychometric properties of available foot scores, the self-reported foot and ankle score (SEFAS) is a valid and reliable outcome measure. The SEFAS was originally developed and tested for the intervention surgery (16), why the validity of SEFAS as a PROM for non-surgical foot problems needs to be studied.

The aim of this study was to assess the validity and reliability of the SEFAS in people with RA who have foot problems (non- surgical referral).

Description of the cohort

Adult patients with RA attending the outpatient clinic at the Danish Hospital for Rheumatic Diseases in Sønderborg.

Data and biological material

The SEFAS questionnaire

Collaborating researchers and departments

SMI, Department of Health Science and Technology, Aalborg University and North Denmark Regional Hospital, Centre for Clinical Research

• Ph.d. student Morten Bilde Simonsen

Sygehus Lillebælt, Den Ortopædkirurgiske Forskningsenhed, Kolding 

• Lektor, PhD., Carsten Jensen

Department of Orthopedics and Clinical Sciences, SUS Malmö, Sweden

• PhD Maria Cöster

Publications associated with the project

We aim to publish a validation study of the questionnaire.