Psychometric properties of the State-Trait Anxiety Inventory among Japanese clinical outpatients.

The factor structure and internal consistency of the Japanese adaptation of the State-Trait Anxiety Inventory Form Y (STAI-JY) were examined for 218 Japanese clinical outpatients (86 males, 132 females) with psychiatric and/or psychosomatic complaints. An initial principal-component analysis revealed that the first three components were considered to reflect the "overall anxiety" component, the "presence-absence of anxiety (positive-negative)" component, and the "state-trait anxiety" component. The component related to presence or absence of anxiety was larger than the state-trait anxiety component. Factors followed by an oblique (promax) rotation were labeled "Anxiety-absent" and "Anxiety-present" factors for a two-factor structure, and "Anxiety-present," "Anxiety-absent/state," and "Anxiety-absent/trait" factors for a three-factor structure that was suggested by the scree test. The internal consistencies for both the state and trait anxiety subscales of the STAI-JY were at a satisfactory level, whereas slightly higher Cronbach's as were obtained from separate calculation for anxiety-present and anxiety-absent items. Similarities and differences in the factor structure of the STAI-JY were discussed in comparison with those reported earlier for the general population in Japan and for individuals in Western countries.