This study aims to validate the FAST by comparing it with established PROMs, namely the Patient-Specific Functional Scale (PSFS) and the Knee Injury and Osteoarthritis Outcome Score (KOOS), to assess its reliability, validity, and responsiveness.
This prospective validation study recruited participants from four public polyclinics in Singapore. Onsite physiotherapists familiar with the study eligibilities referred potential participants to the investigators after the routine physiotherapy assessment. After providing written consent, eligible participants completed outcome measurements with FAST, PSFS, KOOS and the Global Rating of Change Score (GROC) during baseline and follow-up assessments. Validity was evaluated through concurrent validity, construct validity and content validity. Reliability was assessed through test-retest reliability and internal consistency, while responsiveness was measured by changes in the PROM scores. Participants were asked to specify their preferred outcome measure and provide reasons for their choice.
Data analysis involved 107 participants (77 females and 30 males) with a mean age of 66.7 ± 7.7 years. The FAST showed strong construct and content validity, high concurrent validity with the PSFS (Spearman's correlation coefficient = 0.87 to 0.90, p 0.001), and moderate to strong validity with the KOOS, excluding the symptoms dimension (Spearman's correlation coefficient = 0.23 to 0.33, p 0.001). Test-retest reliability and internal consistency were moderate to good. The FAST was favoured by 69% of participants due to its simplicity and pictorial format.
The FAST is a reliable, valid, and preferred tool for assessing functional limitations in knee osteoarthritis patients, overcoming language barriers inherent in existing PROMs. It is particularly useful for patients with low literacy. Future work should focus on extending its use to other musculoskeletal conditions and refining its psychometric properties through further testing.
The implementation of FAST in clinical practice will enhance the evaluation and management of knee osteoarthritis, promoting more inclusive patient-centred care. Its pictorial nature will benefit the evaluation and management of those who suffer knee osteoarthritis regardless of English proficiency or language barriers. Further research is recommended to determine its wider applicability.
Patient-centered
Validation
