Cross-cultural adaptation to Swedish and validation of the Copenhagen Hip and Groin Outcome Score (HAGOS) for pain, symptoms and physical function in patients with hip and groin disability due to femoro-acetabular impingement

PURPOSE: There is a lack of standardised outcome measures in Swedish for active, young and middle-aged patients with hip and groin disability. The purpose of this study was to adapt the Danish version of the Copenhagen Hip and Groin Outcome Score (HAGOS) patient-reported outcome instrument for use in Swedish patients and evaluate the adaptation according to the Consensus-Based Standards for the Selection of Health Status Measurement Instruments checklist.

METHODS: Cross-cultural adaptation was performed in several steps, including translation, back-translation, expert review and pretesting. The final version was evaluated for reliability, validity and responsiveness. Five hundred and two patients (337 men and 167 women, mean age 37, range 15-75) were included in the study.

RESULTS: Cronbach's alpha for the six HAGOS-S subscales ranged from 0.77 to 0.89. Significant correlations were obtained with the international Hip Outcome Tool average score (r s = 0.37-0.68; p < 0.01) and a standardised instrument, the EuroQol, EQ-5D total score (r s = 0.40-0.60, p = 0.01), for use as a measurement of health outcome. Test-retest reliability (intraclass correlation coefficient) ranged from 0.81 to 0.87 for the six HAGOS-S subscales. The smallest detectable change ranged from 7.8 to 16.1 at individual level and 1.6-3.2 at group level. Factor analysis revealed that the six HAGOS-S subscales had one strong factor per subscale. Effect sizes were generally medium or large.

CONCLUSION: The Swedish version of the HAGOS is a valid, reliable and responsive instrument that can be used both for research and in the clinical setting at individual and group level.