TY - JOUR
T1 - Psychometric properties of the Intolerance of Uncertainty Scale-12 in generalized anxiety disorder
T2 - assessment of factor structure, measurement properties and clinical utility
AU - Wilson, Emily J.
AU - Stapinski, Lexine
AU - Dueber, David M.
AU - Rapee, Ronald M.
AU - Burton, Amy L.
AU - Abbott, Maree J.
PY - 2020/12
Y1 - 2020/12
N2 - Intolerance of uncertainty is a psychological vulnerability implicated in the development and maintenance of generalized anxiety disorder (GAD). The Intolerance of Uncertainty Scale-12 (IUS-12) is a widely used measure, however no studies have thoroughly tested the psychometric properties in a clinically diagnosed GAD sample. This study aimed to evaluate the factor structure, measurement properties and clinical utility of the IUS-12 in clinical and non-clinical samples. Participants were screened using the Anxiety Disorders Interview Schedule for DSM-IV to ascertain clinical (n = 136: principal diagnosis of GAD) or non-clinical status (n = 76). Confirmatory factor analysis determined that the bifactor type (two-factor testlet) model demonstrated significantly better fit in comparison to the unidimensional model for the clinical sample. The IUS-12 exhibited limited multidimensionality indicating that only the total score provides meaningful interpretation. The IUS-12 demonstrated good construct validity (with DASS-21, MCQ-30, and PSWQ), good internal consistency, as well as good test-retest reliability over 12-weeks. The IUS-12 demonstrated responsivity to treatment following cognitive behavioral therapy and mindfulness based psychological interventions. Receiver operating characteristic curve analysis indicated an optimal cut-off score of 28 for distinguishing individuals with GAD from non-clinical cases. Overall, the IUS-12 is a valid, reliable and clinically useful instrument for individuals with GAD.
AB - Intolerance of uncertainty is a psychological vulnerability implicated in the development and maintenance of generalized anxiety disorder (GAD). The Intolerance of Uncertainty Scale-12 (IUS-12) is a widely used measure, however no studies have thoroughly tested the psychometric properties in a clinically diagnosed GAD sample. This study aimed to evaluate the factor structure, measurement properties and clinical utility of the IUS-12 in clinical and non-clinical samples. Participants were screened using the Anxiety Disorders Interview Schedule for DSM-IV to ascertain clinical (n = 136: principal diagnosis of GAD) or non-clinical status (n = 76). Confirmatory factor analysis determined that the bifactor type (two-factor testlet) model demonstrated significantly better fit in comparison to the unidimensional model for the clinical sample. The IUS-12 exhibited limited multidimensionality indicating that only the total score provides meaningful interpretation. The IUS-12 demonstrated good construct validity (with DASS-21, MCQ-30, and PSWQ), good internal consistency, as well as good test-retest reliability over 12-weeks. The IUS-12 demonstrated responsivity to treatment following cognitive behavioral therapy and mindfulness based psychological interventions. Receiver operating characteristic curve analysis indicated an optimal cut-off score of 28 for distinguishing individuals with GAD from non-clinical cases. Overall, the IUS-12 is a valid, reliable and clinically useful instrument for individuals with GAD.
KW - generalized anxiety disorder
KW - intolerance of uncertainty
KW - confirmatory factor analysis
KW - psychometrics
UR - http://www.scopus.com/inward/record.url?scp=85091636808&partnerID=8YFLogxK
U2 - 10.1016/j.janxdis.2020.102309
DO - 10.1016/j.janxdis.2020.102309
M3 - Article
C2 - 33002756
AN - SCOPUS:85091636808
VL - 76
SP - 1
EP - 8
JO - Journal of Anxiety Disorders
JF - Journal of Anxiety Disorders
SN - 0887-6185
M1 - 102309
ER -