Cross‐cultural adaptation and validation of the KOOS, JR questionnaire for assessing knee osteoarthritis in Spanish‐speaking patients

Abstract

AbstractPurposeThe present study aims to translate, adapt and validate a Spanish version of the Knee Injury and Osteoarthritis Outcome Score, Joint Replacement (KOOS, JR), including a reliability and validity analysis in patients with knee osteoarthritis (OA).MethodsThis study conducted a prospective validation study following the six stages of the “Guidelines for the Process of Cross‐Cultural Adaptation of Self‐Report Measures”. Psychometric testing was conducted in patients with knee osteoarthritis. Subjects answered the Spanish KOOS, JR (S‐KOOS, JR) and a validated Spanish Oxford Knee Score (S‐OKS). Retest was conducted at 10 days. Acceptability, floor and ceiling effect, internal consistency (Cronbach’s α), reproducibility (mixed‐effect model coefficient [MEMC]) and construct validity (Spearman’s correlation; p = 0.05) were assessed.ResultsForty‐one patients (mean age: 65.6 ± 5.39; 48.8% female) participated in the study. All patients (100%) answered both scores during the first assessment and 38 (92.7%) during the second assessment. All patient‐reported outcomes measures were answered completely (100%). The S‐KOOS, JR resulted in 100% acceptability when answered. There were no ceiling or floor effects detected. The Cronbach’s α for the S‐KOOS, JR was 0.927 and its MEMC was 0.852 (CI 95% 0.636–1.078). The Spearman’s correlation between the S‐KOOS, JR and the S‐OKS was 0.711 (CI 0.345–0.608; p < 0.001) and 0.870 (CI 0.444–0.651; p < 0.001) for the first and second assessments, respectively.ConclusionThe S‐KOOS, JR has very high internal consistency and reproducibility, with a high correlation with the S‐OKS; it is a reliable and valid instrument for characterising Spanish‐speaking patients suffering from knee OA.Level of evidenceIV.