PMS29 Qualitative Study to Understand the Patient Experience of Knee Osteoarthritis (OA) and Assess the Content Validity of the Knee Injury and Osteoarthritis Outcome Score (KOOS) and HIP Disability and Osteoarthritis Outcome Score (HOOS) Measures

Abstract

Osteoarthritis (OA) affects 30-million people in the USA, more commonly affecting women. Despite available treatments focusing on symptomatic relief, most patients report inadequate pain management and reduced health-related quality of life. This study aimed to understand knee OA disease burden and to confirm content validity of the Knee injury and Osteoarthritis Outcome Score (KOOS) and Hip Disability and Osteoarthritis Outcome Score (HOOS) in a population that included older patients. A draft conceptual framework was development from reviews of literature and online OA-patient forums. Existing knee OA patient-reported outcome (PRO) measures were also reviewed. Concept elicitation (CE) interviews were conducted with knee OA patients (with/without hip/hand OA), exploring patients’ symptoms, treatments, and impacts. The conceptual model was refined and used to assess coverage of the PRO measures. The KOOS and HOOS were selected for interviews to further confirm their content validity. Three clinicians and a patient advocate provided expert input throughout this study. Thirty patients participated in the CE interviews (age 40-78 years; 60% female). A multitude of symptoms characterized knee OA, markedly pain, stiffness, and swelling. Pain was considered most bothersome and important to treat, with substantial impact on functioning. Treatment symptom relief was partial and/or short-lived. Thirty patients participated in the cognitive interviews (age 40-76 years; 60% female) where 20 and 10 patients were debriefed the KOOS and HOOS, respectively. Most patients confirmed that the items were relevant, well understood and interpreted as intended, although with reports of some unfamiliar phrases such as ‘knee catch/hang up,’ ‘straightening hip fully’ and ‘twisting/pivoting on loaded leg’. Pain, stiffness and swelling are defining knee OA symptoms, which substantially impact functioning, and are only partially relieved by current treatments. The KOOS and HOOS demonstrated strong content validity but may benefit from minor modification (or patient training) to ensure that items are interpreted consistently.