Translation, validity, and reliability of disability rating scale in Iranian patients with traumatic brain injury


1 Guilan Road Trauma Research Center, PourSina Hospital, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran

2 Department of Psychology, University of Guilan, Rasht, Iran

3 Guilan Road Trauma Research Center, PourSina Hospital; Department of Neurosurgery, School of Medicine, Guilan University of Medical Sciences, Rasht, Iran


Background: The Disability Rating Scale (DRS) is a short, efficient, and rapid instrument for assessing levels of functional disability, but little information is available on the translation and psychometric properties of its Persian version, especially for traumatic brain injury (TBI) patients. The aim of this study was to translate and adapt the Persian version of DRS and to determine the psychometric properties of the Persian version of this scale in patients with TBI. Materials and Methods: In this analytical cross-sectional study, 191 TBI patients (age range, 16–86 years) referred to the physiotherapy Center of PourSina Hospital in Rasht, Iran, were selected through census sampling. First, the DRS was translated into Persian, and then, the validity, reliability, and repeatability of DRS scores were evaluated. All patients were evaluated on admission and at discharge through the Glasgow Coma Scale (GCS) and Functional Independence Measure (FIM). Results: According to the reports of the translators, translation of the DRS into Persian language was easy. The quality of translation (including translation clarity, common language usage, conceptual equivalence, and overall quality of translation) was generally favorable. Inter-raters' reliability on admission and at discharge stages was excellent (intraclass correlation coefficient = 0.93–0.94). Cronbach's alpha values for the internal consistency of DRS on admission and at discharge stages were 0.96 and 0.97, respectively. The results showed a strong inverse relationship of DRS scores on admission and at discharge with GCS and FIM scores (in all cases more than 0.70, P < 0.0001). Conclusion: The validity, reliability, and repeatability of the DRS scores for the Persian version were confirmed. These results reflect that DRS can be used to determine the effects of therapeutic/rehabilitation interventions on levels of functional disability in Iranian patients with TBI.


1. van Deynse H, Van Belleghem G, Lauwaert D, Moens M, Pien K, Devos S, et al. The incremental cost of traumatic brain injury during the first year after a road traffic accident. Brain Inj 2019;33:1234‑44.
2. Myburgh JA, Cooper DJ, Finfer SR, Venkatesh B, Jones D, Higgins A, et al. Epidemiology and 12‑month outcomes from traumatic brain injury in australia and new zealand. J Trauma 2008;64:854‑62.
3. Williams MW, Smith EL. Clinical utility and psychometric properties of the Disability Rating Scale with individuals with traumatic brain injury. Rehabil Psychol 2017;62:407‑8.
4. Lee YH, Chang KH, Escorpizo R, Chi WC, Yen CF, Liao HF, et al. Accuracy of the World Health Organization Disability Assessment Schedule 2.0 (WHODAS 2.0) score as an objective assessment tool for predicting return‑to‑work status after head and neck cancer in male survivors. Support Care Cancer 2019;27:433‑41.
5. Hall KM, Hamilton BB, Gordon WA, Zasler ND. Characteristics and comparisons of functional assessment indices: Disability rating scale, functional independence measure, and functional assessment measure. J Head Trauma Rehabilit 1993;8:60‑74.
6. Deepika A, Devi BI, Shukla D. Predictive validity of disability rating scale in determining functional outcome in patients with severe traumatic brain injury. Neurol India 2017;65:83‑6.
7. Malec JF, Hammond FM, Giacino JT, Whyte J, Wright J. Structured interview to improve the reliability and psychometric integrity of the Disability Rating Scale. Arch Phys Med Rehabil 2012;93:1603‑8.
8. Pretz CR, Malec JF, Hammond FM. Longitudinal description of the disability rating scale for individuals in the National Institute on Disability and Rehabilitation Research traumatic brain injury model systems national database. Arch Phys Med Rehabil 2013;94:2478‑85.
9. van Baalen B, Odding E, van Woensel MP, Roebroeck ME. Reliability and sensitivity to change of measurement instruments used in a traumatic brain injury population. Clin Rehabil 2006;20:686‑700.
10. Finch E, Brooks D, Stratford PW, Mayo NE. Physical rehabilitation outcome measures: A Guide to Enhanced Clinical Decision Making. 2nd ed. Toronto: Lippincott, Williams & Wilkins; 2002. p. 3‑5, 15‑33.
11. Cole B, Finch E, Gowland C, Mayo N. Back and/or pain measures. In: Basmajian J, editor. Physical Rehabilitation Outcome Measures. Toronto (ON): Williams & Wilkins, Health and Welfare Canada and Canadian Physiotherapy Association; 1995. p. 1‑23.
12. Wade DT. Measurement in Neurological Rehabilitation. Oxford, NewYork, Tokyo: Oxford University Press; 1992. p. 15‑7, 35‑43.
13. Perneger TV, Leplège A, Etter JF. Cross‑cultural adaptation of a psychometric instrument: Two methods compared. J Clin Epidemiol 1999;52:1037‑46.
14. Rezaei S, Dehnadi Moghadam A, Khodadadi N, Rahmatpour P. Functional independence measure in Iran: A confirmatory factor analysis and evaluation of ceiling and floor effects in traumatic brain injury patients. Arch Trauma Res 2015;4:e25363.
15. Dehnadi‑Moghadam A, Rezaei S, Khodadadi N, Rahmatpour P. Psychometric properties of the functional independence measure (FIM) in Iranian patients with traumatic brain injury. Trauma Monthly 2017;22.
16. McNett M. A review of the predictive ability of Glasgow Coma Scale scores in head‑injured patients. J Neurosci Nurs 2007;39:68‑75.
17. Rezaei S, Dehnadi Moghadam A, Khodadadi N, Rahmatpour P, Salehpour GH. Prediction of motor and cognitive outcome in acute traumatic brain injury based on length of hospital stay, Glasgow coma scale score (GCS), mental status and substance abuse: A case study of emergency and neurosurgery section in Rasht Poursina hospital. J Iran Soc Anaesthesiol Intensive Care 2013;82:24‑35.
18. Koo TK, Li MY. A guideline of selecting and reporting intraclass correlation coefficients for reliability research. J Chiropr Med 2016;15:155‑63.
19. Tavakol M, Dennick R. Making sense of Cronbach’s alpha. Int J Med Educ 2011;2:53‑5.
20. Fermanian J. Measuring agreement between 2 observers: A quantitative case. Rev Epidemiol Sante Publique 1984;32:408‑13.
21. Bullinger M, Alonso J, Apolone G, Leplège A, Sullivan M, Wood‑Dauphinee S, et al. Translating health status questionnaires and evaluating their quality: The IQOLA Project approach. International Quality of Life Assessment. J Clin Epidemiol 1998;51:913‑23.
22. Drukker M, Kaplan C, Feron F, van Os J. Children’s health‑related quality of life, neighbourhood socio‑economic deprivation and social capital. A contextual analysis. Soc Sci Med 2003;57:825‑41.
23. Iglesias CP, Birks Y, Nelson EA, Scanlon E, Cullum NA. Quality of life of people with venous leg ulcers: A comparison of the discriminative and responsive characteristics of two generic and a disease specific instruments. Qual Life Res 2005;14:1705‑18.
24. Montazeri A, Goshtasebi A, Vahdaninia M, Gandek B. The short form health survey (SF‑36): Translation and validation study of the Iranian version. Qual Life Res 2005;14:875‑82.
25. Moin P, Khalighinejad N, Yusefi A, Farajzadegan Z, Barekatain M. Converting three general‑cognitive function scales into persian and assessment of their validity and reliability. Int J Prev Med 2011;2:82‑7.