Birth Order and Sibling Gender Ratio of a Clinical Sample
The Translation and Psychometric Assessment of the Persian Version of the Sheehan Disability Scale Masoumeh Amin-Esmaeili, MD 2 Abbas Motevalian, MD 3 Afarin Rahimi-Movaghar, MD 4 Ahmad Hajebi, MD 3 Mitra Hefazi, MD 3 Reza Radgoodarzi, MD 5 Vandad Sharifi, Md
1 Department for Mental Health and Substance Abuse, Iranian Research Center for HIV/AIDS (IRCHA), Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran 2 School of Public Health, Iran University of Medical Sciences, Tehran, Iran 3 Iranian National Center for Addiction Studies (INCAS), Iranian Institute for Reduction of High-Risk Behaviors, Tehran University of Medical Sciences, Tehran, Iran 4 Mental Health Research Centre, Tehran Psychiatric Institute, Iran University of Medical Sciences, Tehran, Iran 5 Department of Psychiatry, Tehran University of Medical Sciences, Tehran, Iran
Objective: The Sheehan Disability Scale (SDS) assesses disability in four domains of home management, work responsibilities, close relationships and social life. The main objective of this study was to develop the Persian version of the SDS. Method: Two steps of field work followed the Persian translation and cultural adaptation of the tool: First, the internal consistency and convergent validity was examined in 104 clinical cases recruited from inpatient and outpatient psychiatric services, using 36-item Short Form Health Survey (SF-36) and Global Assessment of Functioning (GAF). Then 88 individuals were randomly selected from the adult general population to assess internal consistency, inter-rater reliability and known group validity. Results: In the clinical settings, Cronbach’s α coefficient was 0.88 and item-total correlation ranged from 0.71 to 0.78 in various domains. The correlation between SDS and SF-36 (P 0.80) indicates that each area is consistent with the other areas and represents a single construct, which is similarly shown in other studies. The study on patients with bipolar disorders reported Cronbach’s α coefficient of 0.89 for the English version of the SDS (20). The Spanish version of the SDS met a strong internal consistency (α = 0.83) in the primary care setting as well (5). World Mental Health Survey replicated the same findings (Cronbach’s α coefficient 0.82 to 0.92) for the general population across the participating countries (1). The SDS is significantly correlated with all the subscales of the SF36 as a self-reported instrument, as well as “days out of role” in the expected direction, supporting the convergent validity of the SDS. These findings are consistent with previous studies that reported a moderate correlation between the SDS and SF-36 in bipolar patients (20). “Severe or very severe scores” in at least two domains of the SDS had the highest correlation with mental and general health subscales of the SF-36. We also found a satisfactory
correlation (0.52) between “severe or very severe scores” in at least two domains of the SDS and the mean of “days out of role.” However, the SDS was not correlated with GAF in the clinical sample. A majority of the clinical sample consisted of patients with severe mental disorders such as bipolar disorder and schizophrenia. Authors believe that this might have led to the fact that these patients had unintentionally reported a better functional status with the self-administered tools. On the other hand, GAF is a clinician-rated scale and has a scoring system based on observations, interviews and reviews of the medical records which provide a more comprehensive information on functioning and psychiatric symptoms. This finding suggests the lower applicability of the SDS in severe cases in the acute phase of the illness. According to our knowledge, this was the first time that test-retest reliability of the SDS has been assessed in the general population. One previous reliability study on the clinical cases found acceptable reliability for social life/ leisure activity (20). However, our assessment of reliability showed a strong agreement between the two rounds on work and school functional status, but it was not acceptable in other domains. This difference might be the result of the cultural variations in the perception of major life domains. The known group validity analysis showed that individuals with a psychiatric disorder could be distinguished from people without a psychiatric illness by the SDS; therefore, the SDS shows a good discriminative validity. In other studies on social phobia and post-traumatic stress disorder, a similarly good discriminative validity has also been reported using the SDS (21, 22). Validating an instrument, which has originally been developed in a different culture, is generally a difficult
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Psychometric Assessment of the Sheehan
task. Moreover, the multistage design of the current study added to the complexity. However, the results might be considered of significant value because of several reasons. First, this study incorporated the assessments of the samples from both clinical settings and the general population. Moreover, in the general population, the sampling frame included urban areas from both large and small cities as well as rural areas presenting different subcultures. The study also assessed multiple indicators of validity and reliability. However, the sample in our study was not large enough to enable us to explore the effect of demographic variations on the validity and reliability of the instrument.
Conclusion Validating an internationally standardized tool to evaluate the magnitude of the functional impairment of psychiatric disorders would provide an opportunity for the direct comparison of information across countries. Overall, the SDS seems to be a valid scale for the measurement of disability in clinical settings and the Iranian general population. It is a short, simple and easy to use instrument for large scale population surveys.
Acknowledgement This study as a part of the Iran Mental Health Survey has been financially supported by the Ministry of Health through the contract number of 132-1491 of Tehran University of Medical Sciences and the contract number of 89-D-432-143 of Mental Health Research Network. The authors acknowledge the contribution of Dr. Samaneh Kariman, Reza Davasaz Irani, Dr. Behrang Shadlou and Fahima Farrahi in conducting the study.
Ormel J, Petukhova M, Chatterji S, AguilarGaxiola S, Alonso J, Angermeyer MC, et al. Disability and treatment of specific mental and physical disorders across the world. Br J Psychiatry 2008; 192: 368-375. Demyttenaere K, Bruffaerts R, Posada-Villa J, Gasquet I, Kovess V, Lepine JP, et al. Prevalence, severity, and unmet need for treatment of mental disorders in the World Health Organization World Mental Health Surveys. JAMA 2004; 291: 2581-2590. Ustun B, Kennedy C. What is "functional impairment"? Disentangling disability from clinical significance. World Psychiatry 2009; 8: 82-85. Sheehan DV, Harnett-Sheehan K , Raj BA. The measurement of disability. Int Clin Psychopharmacol 1996; 11 Suppl 3: 89-95. Luciano JV, Bertsch J, Salvador-Carulla L, Tomas JM, Fernandez A, Pinto-Meza A, et al. Factor structure, internal consistency and
Iranian J Psychiatry 9:3, July 2014 ijps.tums.ac.ir
construct validity of the Sheehan Disability Scale in a Spanish primary care sample. J Eval Clin Pract 2010; 16: 895-901. Alhasnawi S, Sadik S, Rasheed M, Baban A, Al-Alak MM, Othman AY, et al. The prevalence and correlates of DSM-IV disorders in the Iraq Mental Health Survey (IMHS). World Psychiatry 2009; 8: 97-109. Levinson D, Lerner Y, Zilber N, Grinshpoon A , Levav I. Twelve-month service utilization rates for mental health reasons: data from the Israel National Health Survey. Isr J Psychiatry Relat Sci 2007; 44: 114-125. Williams DR, Herman A, Stein DJ, Heeringa SG, Jackson PB, Moomal H, et al. Twelvemonth mental disorders in South Africa: prevalence, service use and demographic correlates in the population-based South African Stress and Health Study. Psychol Med 2008; 38: 211-220. Kawakami N, Takeshima T, Ono Y, Uda H, Hata Y, Nakane Y, et al. Twelve-month prevalence, severity, and treatment of common mental disorders in communities in Japan: preliminary finding from the World Mental Health Japan Survey 2002-2003. Psychiatry Clin Neurosci 2005; 59: 441-452. Karam EG, Mneimneh ZN, Karam AN, Fayyad JA, Nasser SC, Chatterji S, et al. Prevalence and treatment of mental disorders in Lebanon: a national epidemiological survey. Lancet 2006; 367: 1000-1006. Druss BG, Hwang I, Petukhova M, Sampson NA, Wang PS, Kessler RC. Impairment in role functioning in mental and chronic medical disorders in the United States: results from the National Comorbidity Survey Replication. Mol Psychiatry 2009; 14: 728-737. Beaton DE, Bombardier C, Guillemin F , Ferraz MB. Guidelines for the process of cross-cultural adaptation of self-report measures. Spine (Phila Pa 1976) 2000; 25: 3186-3191. American Psychological Association. Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) (DSM-III-R). Washington DC: APA; 1987. Montazeri A, Goshtasebi A, Vahdaninia M , Gandek B. The Short Form Health Survey (SF36): translation and validation study of the Iranian version. Qual Life Res 2005; 14: 875882. Nunnally JC, Bernstein IH. Psychometric theory 3rd ed. New York: McGraw-Hill; 1994. Alaghband Rad J. Study of the reliability, validity, and feasibility of Farsi translation of the Composite International Diagnostic Interview (CIDI). In: Ahmadi Abhari SA, Malakooti K, Nasr Esfahani M, Razzaghi EM, Sadeghi M, Yasamy MT, editors. Mental health effects of Iraqi invasion of Kuwait in a war – torn population of Iran: an epidemiological and financial study of the consequences of the Kuwaiti oil well fire disaster in the aftermath of Iraqi invasion of Kuwait in 1991, United Nations Compensation Commission (UNCC) Monitoring and Assessment Project. Tehran -
Amin-Esmaeili, Motevalian, Rahimi-Movaghar, et al
Iran: Islamic Republic of Iran Ministry of Health, Committee for assessment and follow up for damages resulting from the Iraq–Kuwait War; 2003. 17. Kish L. A Procedure for Objective Respondent Selection within the Household. Journal of the American Statistical Association 1949; 44: 380-7. 18. Lee J, Koh D , Ong CN. Statistical evaluation of agreement between two methods for measuring a quantitative variable. Comput Biol Med 1989; 19: 61-70. 19. Kline P. A handbook of test construction: introduction to psychometric design. London, UK: Methuen; 1986. 20. Arbuckle R, Frye MA, Brecher M, Paulsson B, Rajagopalan K, Palmer S, et al. The psychometric validation of the Sheehan Disability Scale (SDS) in patients with bipolar disorder. Psychiatry Res 2009; 165: 163-174. 21. Connor KM, Davidson JR. SPRINT: a brief global assessment of post-traumatic stress disorder. Int Clin Psychopharmacol 2001; 16: 279-284. 22. Hambrick JP, Turk CL, Heimberg RG, Schneier FR, Liebowitz MR. Psychometric properties of disability measures among patients with social anxiety disorder. J Anxiety Disord 2004; 18: 825-839.
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