Examining cut-off values for the state-trait anxiety inventory

Abstract

The State-Trait Anxiety Inventory (STAI) is a widely used instrument in clinical practice and for research purposes. This study aimed to determine a cut-off score for STAI state and trait anxiety scales that differentiates between healthy adults and those with anxiety disorders. A total of 180 patients took part in the study; 80 patients were part of the control group, and 100 were part of the study group. The study group consisted of those with any type of anxiety disorder as assessed by a semi-structured clinical interview by a psychiatrist based on DSM-IV criteria. The control group consisted of people with no diagnosis of any type of anxiety disorder. Cut-off values for the scales were determined using receiver operating characteristic analysis. This study found that a cut-off value of 41 was optimal (sensitivity=78.3; specificity=71.2) for the STAI-I and, a value of 44 (sensitivity=93.5; specificity=57.4) was optimal for the STAI-II.