Psychometric properties of the world health organization disability assessment schedule II-12 Item (WHODAS II) in trauma patients

Background: The 12-item WHODAS II is widely used for assessing disability among different populations. This study aimed at assessing the psychometric properties of the Persian version of the 12-item WHODAS II among trauma patients. Patients and Methods: In this methodological study, 220 patients aging 15-65-year-old hospitalized in Shahid Beheshti Hospital, Kashan, Iran, were studied. The WHODAS II was used for data collection. The reliability of this schedule was assessed by evaluating its internal consistency. Its validity was evaluated by using the known-groups approach and the convergent validity method. The exploratory and the confirmatory factor analysis techniques were also used for assessing the factor structure of the schedule. Results: The mean of participants' ages was 34.7 +/- 14.5 years. Most of the participants were male patients (84.1%), had multiple injury (77.7%), and had been injured in road traffic accidents (76.8%). The Cronbach's alpha of the WHODAS II was 0.91, confirming its acceptable internal consistency. Known-groups comparisons revealed that this schedule can satisfactorily differentiate among patients with different severity of trauma (P value < 0.0001). The results of exploratory factor analysis showed that the WHODAS II had a two-factor structure while the confirmatory factor analysis revealed that one-factor model fitted the data. Conclusion: Study findings suggest that the Persian version of the 12-item WHODAS II is a valid and reliable scale for assessing trauma patients' disability. More Large-scale studies are needed for assessing the validity and the reliability of this schedule among other patients. (C) 2015 Elsevier Ltd. All rights reserved.