The GAD-7 as a Tool for Measuring Generalized Anxiety in Multiple Sclerosis
|Title||The GAD-7 as a Tool for Measuring Generalized Anxiety in Multiple Sclerosis|
|Publication Type||Journal Article|
|Authors||Terrill AL, Hartoonian N, Beier M, Salem R, Alschuler K|
|Journal||International Journal of MS Care|
Background: Generalized anxiety disorder (GAD) is common in multiple sclerosis (MS) but understudied. Reliable and valid measures are needed to advance clinical care and expand research in this area. The objectives of this study were to 1) examine the psychometric properties of the 7-item Generalized Anxiety Disorder Scale (GAD-7) in individuals with MS, and 2) examine correlates of GAD.
Methods: Participants (N = 513) completed the anxiety module of the Patient Health Questionnaire (GAD-7). To evaluate psychometric properties of the GAD-7, the sample was randomly split to conduct exploratory (EFA) and confirmatory factor analyses (CFA).
Results: Based on the EFA, a 1-factor structure was specified for the CFA, which showed excellent global fit to the data, χ212 = 15.17, P = .23, comparative fit index (CFI) = 0.99, root-mean-square error of approximation (RMSEA) = 0.03, standardized root mean square residual (SRMR) = 0.03. The Cronbach alpha (0.75) indicated acceptable internal consistency for the scale. Furthermore, the GAD-7 was highly correlated with the Hospital Anxiety and Depression Scale-Anxiety (HADS-A) (r = 0.70). Age and duration of MS were both negatively associated with GAD. Higher GAD-7 scores were observed among women and individuals with secondary progressive MS. Individuals higher on the GAD-7 also endorsed more depressive symptoms.
Conclusions: The findings support the reliability and internal validity of the GAD-7 for use in MS. Additionally, correlational analyses revealed important relationships with demographics, disease course, and depressive symptoms, which suggest the need for further anxiety research.