Understanding the relationships between health outcomes in generalized anxiety disorder clinical trials
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Background and Aims
The Wilson–Cleary health outcomes model is a hypothesized pathway linking traditional clinical variables to health-related quality of life (HRQL). This study tested the application of the Wilson–Cleary model to a patient population with generalized anxiety disorder (GAD) using longitudinal clinical trial data.
These secondary analyses pooled data from three similar 8-week, placebo-controlled, double-blind, randomized, multicenter trials of quetiapine XR therapy in GAD. Relevant health assessments for the model concepts included the Clinical Global Impression-Severity of Illness, Hamilton Rating Scale for Anxiety, the Pittsburgh Sleep Quality Index and Quality of Life Enjoyment and Satisfaction Questionnaire-Short Form. A lagged path model tested whether the hypothesized relationships at baseline and week 8 between the concepts of the adapted Wilson–Cleary model were consistent with the observed data.
The resulting model fit the data (RMSEA = 0.077; CFI = 0.98; NFI = 0.96) and explained 56% of the variance in overall quality of life assessment at baseline and 69% of the variance in this assessment at week 8. Moderate to strong relationships between the adjacent hypothesized concepts support the specified model.
This adapted Wilson–Cleary model for health outcomes validated in GAD should improve the understanding and usefulness of health status measurements in this condition and increase the applications of this model to other clinical trial data.
KeywordsGeneralized anxiety disorder Wilson–Cleary model Health-related quality of life Health assessment Path analysis Lagged model
This work was funded by AstraZeneca.
- 1.American Psychiatric Association. (1994). Diagnostic and Statistical Manual of Mental Disorders. 4th ed. Washington, DC: American Psychiatric Press.Google Scholar
- 2.Arnold, R., Ranchor, A. V., Koeter, G. H., de Jongste, M. J., & Sanderman, R. (2005). Consequences of chronic obstructive pulmonary disease and chronic heart failure: The relationship between objective and subjective health. Social Science and Medicine, 61(10), 2144–2154.CrossRefPubMedGoogle Scholar
- 4.Atkinson, S., Khan, A., Joyce, M., Eggens, I., Baldytcheva, I., & Brecher, M. (2008). Efficacy and tolerability of once-daily extended release quetiapine fumarate (quetiapine XR) monotherapy in patients with generalised anxiety disorder. International Journal of Neuropsychopharmacology, 11(Suppl 1), 277.Google Scholar
- 5.Bandelow, B., Chouinard, G., Bobes, J., Ahokas, A., Eggens, I., Liu, S., et al. (2010). Extended-release quetiapine fumarate (quetiapine XR): A once-daily monotherapy effective in generalized anxiety disorder data from a randomized double-blind placebo- and active-controlled study. International Journal of Neuropsychopharmacology, 13(3), 305–320.CrossRefPubMedGoogle Scholar
- 11.Cohen, J. (1988). Statistical power analysis for the behavioral sciences (2nd ed.). Hillsdale, NJ: Lawrence Earlbaum.Google Scholar
- 14.Demyttenaere, K., Andersen, H. F., & Reines, E. H. (2008). Impact of escitalopram treatment on Quality of Life Enjoyment and Satisfaction Questionnaire scores in major depressive disorder and generalized anxiety disorder. International Clinical Psychopharmacology, 23(5), 276–286.CrossRefPubMedGoogle Scholar
- 16.Endicott, J., Rajagopalan, K., Minkwitz, M., & Macfadden, W. (2007). A randomized, double-blind, placebo-controlled study of quetiapine in the treatment of bipolar I and II depression: Improvements in quality of life. International Clinical Psychopharmacology, 22(1), 29–37.CrossRefPubMedGoogle Scholar
- 18.ESEMeD/MHEDEA 2000 Investigators. (2004). Prevalence of mental disorders in Europe: Results from the European Study of the Epidemiology of Mental Disorders (ESEMeD) project. Acta Psychiatrica Scandinavica,109(suppl 1):21–27.Google Scholar
- 20.Grant, B. F., Hasin, D. S., Stinson, F. S., et al. (2005). Prevalence, correlates, co-morbidity, and comparative disability of DSM-IV generalized anxiety disorder in the USA: Results from the National Epidemiologic Survey on Alcohol and Related Conditions. Psychological Medicine, 35(12), 1747–1759.CrossRefPubMedGoogle Scholar
- 21.Guy, W. (1976). Clinical global impressions. ECDEU Assessment Manual for Psychopharmacology (pp. 218–222). Rockville, MD: National Institute for Mental Health.Google Scholar
- 23.Hays, R. D., Cunningham, W. E., Sherbourne, C. D., et al. (2000). Health-related quality of life in patients with human immunodeficiency virus infection in the United States: Results from the HIV Cost and Services Utilization Study. American Journal of Medicine, 108(9), 714–722.CrossRefPubMedGoogle Scholar
- 28.Jöreskog, K. G., & Sörbom, D. (2006). LISREL 8.80 for Windows [Computer Software]. Lincolnwood, IL: Scientific Software International.Google Scholar
- 30.Kessler, R. C., Keller, M. B., & Wittchen, H. (2001). The epidemiology of generalized anxiety disorder. In O. Brawman-Mintzer (Ed.), The psychiatric clinics of North America: Generalized anxiety disorder (pp. 19–40). Philadelphia: W.B. Saunders.Google Scholar
- 39.Norman, G., & Streiner, D. (2000). Biostatistics: The bare essentials. Toronto: Decker.Google Scholar
- 41.Orfila, F., Ferrer, M., Lamarca, R., Tebe, C., Domingo-Salvany, A., & Alonso, J. (2006). Gender differences in health-related quality of life among the elderly: The role of objective functional capacity and chronic conditions. Social Science and Medicine, 63(9), 2367–2380.CrossRefPubMedGoogle Scholar
- 44.Ritsner, M., Kurs, R., Gibel, A., Ratner, Y., & Endicott, J. (2005). Validity of an abbreviated Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-18) for schizophrenia, schizoaffective, and mood disorder patients. Quality of Life Research, 14(7), 1693–1703.CrossRefPubMedGoogle Scholar
- 54.Wittchen, H. U., Carter, R. M., Pfister, H., Montgomery, S. A., & Kessler, R. C. (2000). Disabilities and quality of life in pure and comorbid generalized anxiety disorder and major depression in a national survey. International Clinical Psychopharmacology, 15(6), 319–328.CrossRefPubMedGoogle Scholar