Validation of the Spanish version of the hip outcome score: a multicenter study

BACKGROUND The Hip Outcome Score (HOS) is a self-reported questionnaire evaluating the outcomes of treatment interventions for hip pathologies, divided in 19 items of activities of daily life (ADL) and 9 sports' items. The aim of the present study is to translate and validate HOS into Spanish. METHODS A prospective and multicenter study with 100 patients undergoing hip arthroscopy was performed between June 2012 and January 2013. Crosscultural adaptation was used to translate HOS into Spanish. Patients completed the questionnaire before and after surgery. Feasibility, reliability, internal consistency, construct validity (correlation with Western Ontario and McMaster Universities Osteoarthritis Index), ceiling and floor effects and sensitivity to change were assessed for the present study. RESULTS Mean age was 45.05 years old. 36 women and 64 men were included. Feasibility: 13% had at least one missing item within the ADL subscale and 17% within the sport subscale. Reliability: the translated version of HOS was highly reproducible with intraclass correlation coefficient of 0.95 for ADL and 0.94 for the sports subscale. Internal consistency was confirmed with Cronbach's alpha >0.90 in both subscales. Construct validity showed statistically significant correlation with WOMAC. Ceiling effect was observed in 6% and 12% for ADL and sports subscale, respectively. Floor effect was found in 3% and 37% ADL and sports subscale, respectively. Large sensitivity to change was shown in both subscales. CONCLUSION The translated version of HOS into Spanish has shown to be feasible, reliable and sensible to changes for patients undergoing hip arthroscopy. This validated translation of HOS allows for comparisons between studies involving either Spanish- or English-speaking patients. LEVEL OF EVIDENCE Prognostic study, Level I.