Development and validation of the Flare-OA questionnaire for measuring flare in knee and hip osteoarthritis

• Published in: Osteoarthritis and cartilage Vol. 30; no. 5; pp. 689 - 696
• Main Authors: Traore, Y., Epstein, J., Spitz, E., March, L., Maillefert, J.-F., Rutherford, C., Ricatte, C., Alleyrat, C., Cross, M., King, L.K., Callahan, L.F., Fautrel, B., Buttel, T., Hawker, G., Hunter, D.J., Guillemin, F.
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01-05-2022; Elsevier
• Subjects: Female; Flare; Humans; Knee Joint; Life Sciences; Lower limb; Male; Middle Aged; Osteoarthritis; Osteoarthritis, Hip - diagnosis; Osteoarthritis, Knee - diagnosis; Patient-reported outcome; Psychometrics; Psychometrics properties; Quality of Life; Questionnaire; Reproducibility of Results; Surveys and Questionnaires; Psychometrics properties; INSERM; Flare; Questionnaire; Lower limb; MICS; Patient-reported outcome; APEMAC; Centre d'investigation clinique; Osteoarthritis; mesure et évaluation en santé; Adaptation
• ISSN: 1063-4584; 1522-9653
• DOI: 10.1016/j.joca.2021.12.011

Ability to assess flares in osteoarthritis (OA) of the knee and hip (KHOA) is important in clinical care and research. Using mixed methods, we developed a self-reported instrument measuring flare and assessed its psychometric properties.
We constructed questionnaire items from semi-structured interviews and a focus group (patients, clinicians) by using a dual-language (English-French) approach. A Delphi consensus method was used to select the most relevant items. Patients with OA from Australia, France and the United States completed the preliminary Flare-OA, HOOS, KOOS and Mini-OAKHQOL questionnaires online. We used a factor analysis and content approach to reduce items and determine structural validity. We tested the resulting questionnaire (score 0–100) for internal consistency, convergent and known-groups validity.
Initially, 180 statements were generated and reduced to 33 items in five domains (response 0 = not at all, to 10 = absolutely) by Delphi consensus (50 patients, 116 professionals) and an expert meeting. After 398 patients (mean [SD] age 64 [8.5] years, 70.4% female, 86.7% knee OA) completed the questionnaire, it was reduced to 19 items by factor analysis and a content approach (RMSEA = 0.06; CFI = 0.96; TLI = 0.94). The Cronbach's alpha was >0.9 for the five domains and the whole questionnaire. Correlation coefficients between Flare-OA and other instrument scores were as predicted, supporting construct validity. The difference in Flare-OA score between patients with and without flare (31.8) largely exceeded 2 SEM (10.2).
Flare-OA is a valid and reliable patient-reported instrument for assessing the occurrence and severity of flare in patients with KHOA in clinical research.