Factor Structure of The Malay-Version Generalized Anxiety Disorder-7 (GAD-7) Questionnaire among Patients with Diabetes Mellitus
Factor Analysis of the Malay-version GAD-7
Vol. 15 No. 1 : 2020 (208-217)
Abstract
The Malay-version Generalised Anxiety Disorder-7 (GAD-7) questionnaire previously demonstrated good concurrent validity, i.e. sensitivity and specificity as a screening instrument for anxiety. However, its psychometric properties on factorial validity had not been further investigated. This study investigated the factor structure of the Malay-version GAD-7 in among 300 diabetic outpatients (mean age: 60.4 years, SD: 13.4 years; 52.7% male) in a Malaysian university hospital in Kuala Lumpur. Study participants completed questionnaires on sociodemographic information, the GAD-7, the Beck’s Depression Inventory (BDI), and the WHOQOL-BREF instrument. The Malay-version GAD-7 displayed good internal consistency (Cronbach’s α=0.91) and satisfactory convergent validity with depression (Pearson’s R=0.642, p<0.001), overall perceptions of QOL (R=-0.277, p<0.001) and health (R=-0.257, p<0.001). In exploratory factor analysis, there was only one component with an eigenvalue >1 (eigenvalue=4.614), suggesting a unidimensional factor structure. All seven items were loaded on a higher-order factor (‘generalized anxiety’) in confirmatory factor analysis. This model did not have a good fit with the data. After examining the modification indices, the model was respecified to allow covariance of the error terms of items 1 and 2, and 2 and 3. The respecified model appeared to fit the data better (χ2=35.216, df=12, p<0.001, CFI=0.98, TLI=0.97, RMSEA=0.08, and AIC=67.22). The findings suggested that items 1, 2 and 3 of GAD-7 may share distinctive variance out of that explained by the ‘generalized anxiety’ factor. Overall, the Malay-version GAD-7 appeared to be a valid measurement of the symptoms of anxiety in this study.
Keywords :
anxiety,
confirmatory factor analysis,
Diabetes mellitus,
GAD-7,
Correspondance Address
r. Luke Sy-Cherng Woon. Department of Psychiatry, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre, Jalan Yaacob Latif, Bandar Tun Razak, 56000 Cheras, Kuala Lumpur, Malaysia. Tel: +603-9145 6142 Email: lukewoon@ukm.edu.my
References
Ahmad, A., Abujbara, M., Jaddou, H., Younes, N.A., Ajlouni, K. 2018. Anxiety and depression among adult patients with diabetic foot: prevalence and associated factors. J Clin Med Res 10(5): 411-8.
Alharithy, M.K., Abdalgader, O.R., Alobaylan, M.M., Alsugair, Z.O., Alswat, K.A. 2019. Anxiety prevalence in type 2 diabetes patients in Taif Saudi Arabia. Saudi J Health Sci 8(2): 88-92.
American Diabetic Association. 2014. Standards of Medical Care in Diabetes 2014. Diabetes Care 37(Suppl 1): S14-S80.
Bártolo, A., Monteiro, S., Pereira, A. 2017. Factor structure and construct validity of the Generalized Anxiety Disorder 7-item (GAD-7) among Portuguese college students. Cadernos de Saúde Pública 33(9): e00212716.
Beard, C., Björgvinsson, T. 2014. Beyond generalized anxiety disorder: psychometric properties of the GAD-7 in a heterogeneous psychiatric sample. J Anxiety Disord 28(6): 547-52.
Beck, A.T., Steer, R.A., Garbin, M.G. 1988. Psychometric properties of the Beck Depression Inventory: Twenty-five years of evaluation. Clin Psychol Rev 8(1): 77-100.
Hasanah, C.I., Naing, L., Rahman, A.R.A. 2003. World Health Organization Quality of Life Assessment: Brief Version in Bahasa Malaysia. Med J Malaysia 58(1): 79-88.
Hendrieckx, C., Halliday, J.A., Beeney, L.J., Speight, J. 2016. Diabetes and Emotional Health: A Handbook for Health Professionals Supporting Adults with Type 1 or Type 2 Diabetes. Canberra: National Diabetes Services Scheme.
Hu, L.T., Bentler, P.M. 1995. Evaluating model fit. In Structural equation modeling: Concepts, issues, and applications. Edited by Hoyle RH. Thousand Oaks, CA: Sage; 76-99.
International Diabetes Federation diabetes atlas - 2017 Atlas. Available at: https://diabetesatlas.org/resources/2017-atlas.html. [Accessed: 30th April 2019].
Institute for Public Health. 2008. The Third National Health and Morbidity Survey (NHMS III). Diabetes Mellitus. Kuala Lumpur.
Institute for Public Health. 2015. National Health and Morbidity Survey 2015 (NHMS 2015). Vol II: Non-Communicable Diseases, Risk Factors and Other Health Problems. Kuala Lumpur.
Kader Maideen, S.F., Mohd Sidik, S., Rampal, L., Mukhtar, F. 2015. Prevalence, associated factors and predictors of anxiety: a community survey in Selangor, Malaysia. BMC Psychiatry 15: 262.
Kertz, S., Bigda-Peyton, J., Bjorgvinsson, T. 2013. Validity of the Generalized Anxiety Disorder-7 Scale in an acute psychiatric sample. Clin Psychol Psychother 20(5): 456-64.
Khan, P., Qayyum, N., Malik, F., Khan, T., Khan, M., Tahir, A. 2019. Incidence of anxiety and depression among patients with type 2 diabetes and the predicting factors. Cureus 11(3): e4254.
Kruse, J., Schmitz, N., Thefeld, W. 2003. On the association between diabetes and mental disorders in a community sample: Results from the German National Health Interview and Examination Survey. Diabetes Care 26(6): 1841-6.
Löwe, B., Decker, O., Müller, S., Brähler, E., Schellberg, D., Herzog, W., Herzberg, P.Y. 2008. Validation and standardization of the generalized anxiety disorder screener (GAD-7) in the general population. Med Care 46(3): 266-74.
Mohd Sidik, S., Arroll, B., Goodyear-Smith, F. 2012. Validation of the GAD-7 (Malay version) among women attending a primary care clinic in Malaysia. J Prim Health Care 4(1): 5-11.
Mukhtar, F., Oei, T.P.S. 2008. Exploratory and confirmatory factor validation and psychometric properties of the Beck Depression Inventory for Malays (BDI-Malay) in Malaysia. Malays J Psychiatry 17(1). http://www.psychiatrymalaysia.org/file_dir/16510073164861a7e47a8ae.pdf [Accessed 13th January 2017].
Nefs, G., Hendrieckx, C., Reddy, P., Browne, J.L., Bot, M., Dixon, J., Kyrios, M., Speight, J., Pouwer, F. 2019. Comorbid elevated symptoms of anxiety and depression in adults with type 1 or type 2 diabetes: Results from the International Diabetes MILES Study. J Diabetes Complications 33(8): 523-9.
Spitzer, R.L., Kroenke, K., Williams, J.B.W., Löwe, B. 2006. A brief measure for assessing Generalised Anxiety Disorder. The GAD-7. Arch Intern Med 166(10): 1092-7.
WHOQOL Group. 1998. Development of the World Health Organization WHOQOL-BREF Quality of Life Assessment. Psychol Med 28(3): 551-8.
Woon, L. S.-C., Sidi, H., Ravindran., A., Gosse, P.J., Kaunismaa, E.S., Mainland, R.L., Hatta, N.H., Arnawati, P., Zulkifli, A.Y., Mustafa, N., Abdullah, M.F.I.L. 2020. Depression, anxiety, and associated factors in patients with diabetes: evidence from the anxiety, depression, and personality traits in diabetes mellitus (ADAPT-DM) study. BMC Psychiatry 20: 227.
