Psychometric properties of the Turkish version of the World Health Organization quality of life instrument for people with intellectual and physical disabilities (WHOQOL-DIS-TR)

Objective: The aim of this study was to present the validity and reliability of the Turkish version of the add-on module for the WHOQOL measure of quality of life. The module was used on adults with physical or intellectual disabilities known as the WHOQOL-DIS. Methods: Data were collected from 150 Intellectual Disabled (ID) and 157 Physically Disabled (PD) persons in the Turkish (Izmir) Participating Center of the Global WHOQOL-DIS Project. The WHOQOL-DIS module consisted of 12 disability specific items along with 26 generic items of WHOQOl-Bref. The proposed factorial structure (3 factors) of WHOQOL-DIS global study was used in the psychometric analyses of the Turkish versions of WHOQOL-DIS. Reliability analyses and construct validity were tested via CFA analyses, while convergent and discriminant validity analyses was assessed in relation to Satisfaction with Life Scale (SWLS) and WHO Disability Assessment Schedule-II (WHODAS-II), respectively. Results: Cronbach alpha values of the WHOQOL-DIS factors were as follows for ID and PD samples respectively: Factor 1 (Discrimination and support) = 0.54 and 0.64; Factor 2 (Independence) = 0.78 and 0.79; Factor 3 (Community participation) = 0.88 and 0.83. CFI and RMSEA values were 0.98 and 0.065 for ID sample and 0.98 ve 0.064 for PD sample, respectively. Convergent-discriminant validities were satisfactory for all factors in the PD group (r = 0.27 - 0.62) whereas, Factor 1 was not found discriminative in the ID group (r = 0.09 -0.10) Conclusion: Psychometric properties provided satisfactory evidence of reliability and validity of the PD and ID Turkish versions of WHOQOL-DIS (WHOQOL-DIS-TR-D and WHOQOL-DIS-TR-ID). Nevertheless, the results of Factor 1 (discrimination and support) in ID version should be interpreted with caution. WHOQOL-DIS should be applied to the disabled persons jontly with its core (generic) domains (WHOQOL-BREF) and the disablity module (38 item version) for the sake of holistic evaluation of QOL. We recommend further studies to explore the sensitivity of the WHOQOL-DIS on various variables in the field. © 2018, Turkish Association of Nervous and Mental Health