Have Commonly Utilised Patient-Reported Outcome Measures Been Validated for the Japanese Language and Culture Amongst Patients with Distal Radius Fractures? A Systematic Review

<b>Background:</b> Patient-reported outcome measures (PROMs) are questionnaires used to evaluate a patient's functional status, examine outcomes and inform clinical decisions. PROMs have been primarily developed with English-speaking populations and should be validated in the patient population in whom they are being applied. As present, the validity of commonly utilised distal radius fracture (DRF) PROMs in patients who speak Japanese is unknown. The purpose was to evaluate the validity and psychometric properties of common DRF PROMs in the Japanese population. <b>Methods:</b> A systematic review was conducted to identify published literature on Japanese DRF PROMs, using a comprehensive search strategy based on previous literature. Methodologic quality of PROM adaptation and validation was evaluated using instruments: Guidelines for the Process of Cross-Cultural Adaptation of Self-Report Measures, Quality Criteria for Psychometric Properties of Health Status Questionnaire, and the Consensus-based Standards for the Selection of Health Measurement Instruments Checklist for Cross-Cultural Validity. The level of evidence was then calculated based on the above methodologic quality. <b>Results:</b> Three studies met the inclusion criteria. Amongst them, three PROMs were reported: the Disability of Arm, Shoulder and Hand (DASH), the Patient-Rated Wrist Evaluation (PRWE) and the Quick Disability of the Arm, Shoulder and Hand (QuickDASH). None of the three studies followed all six processes for adaptation, nor assessed all measurement properties. No study demonstrated the completion of more than 7 of the 15 aspects of cross-cultural validity. The PRWE, DASH and QuickDASH all had limited evidence to support the domains of measurement properties evaluating the level of evidence. <b>Conclusions:</b> There is a gap in validated PROMs for Japanese patients with DRFs. As such, commonly utilised PROMs should be adapted and validated or cross-walked to Japanese-specific instruments to ensure reliability, validity and cultural equivalence before widespread use. <b>Level of Evidence:</b> Level III (Diagnostic Studies scale).