The Dutch hip and groin outcome score: Cross-cultural adaptation and validation according to the COSMIN checklist

STUDY DESIGN: Clinical measurement. BACKGROUND: The Copenhagen Hip and Groin Outcome Score (HAGOS) was developed as a patient-reported outcome measure for young, active individuals with hip and groin pain. OBJECTIVES: To cross-culturally adapt and validate a Dutch version of the HAGOS. METHODS: Adaptation and validation were performed according to existing guidelines and the Consensus-based Standards for the selection of health Measurement INstruments checklist. Physically active (Tegner activity score of greater than 2) adults between 18 and 50 years of age with hip and groin pain (numeric pain score of 1 or greater) were included in the study. Reliability (test-retest, internal consistency) was assessed in clinically stable patients. Construct validity was determined by calculating Spearman correlations between the scores on the HAGOS and scores on the Hip disability and Osteoarthritis Outcome Score and European Quality of Life-5 Dimensions subscales. Fifteen hypotheses were defined a priori. Interpretability was considered good when floor and ceiling effects were present in less than 15% of individuals. RESULTS: A Dutch version of the HAGOS was created. Its reliability was tested in 129 individuals and its validity in 194 participants. Test-retest reliability was good (intraclass correlation coefficient = 0.83-0.87). Internal consistency was good (Cronbach α = .81-.92). Construct validity was considered good: 13 of 15 (87%) hypotheses were confirmed. Floor effects (21%) were present for the physical activity subscale. CONCLUSION: The Dutch HAGOS is a reliable and valid patient-reported outcome measure and performs similarly to the original version in its target population. It can be used in clinical as well as research settings. Presence of floor effects should be considered for the physical activity subscale.