Development and validation of static short form and adaptive test for the Taijin Kyofusho Scale to measure the severity of culture-bound social anxiety

Simpler and more precise tools are needed to measure Taijin Kyofusho which is a culture-bound anxiety disorder in East Asian countries. This study aimed to develop and validate a short form and a computerized adaptive test (CAT) of Taijin Kyofusho Scale (TKS), as well as compare the measurement precision of the short form, the CAT version and its original version. Item Response Theory (IRT) method was used to develop static short form and to simulate CAT. The short form consisted of 12 items (a 61% reduction) and the CAT version consisted of average 11.72 items (a 62% reduction) from the original TKS, respectively. Both short form and CAT version have similar levels of accuracy and precision in comparison to the original scale at the group level. However, at the individual level, the CAT version can maintain a more consistent level of precision across the continuum of severity than the short form. The short form of the TKS is sufficient for an initial assessment or screening in the community population. And the CAT version of the TKS is more suitable for tailored treatments in the clinical practice, which could detect detailed changes in the severity of Taijin Kyofusho.