Study Goals: The various versions from the Dysfunctional Beliefs and Attitudes approximately Sleep Range (DBAS) possess limited comparison and summary from the findings across studies. more powerful than with rest diary variables. Sensitivities to improve from the DBAS ratings pursuing CBT-I and with rest improvement had been found, except the DBAS-30 attributions DBAS-16 and subscale medication subscale. Conclusions: The DBAS-16 possesses better internal regularity, a reproducible element structure, strong concurrent validity, and level of sensitivity to change, and for that reason is recommended for study use. The DBAS-30 and DBAS-10 have their personal advantages, but you will find limitations in their application like a quantitative measure in study. Citation: Chung KF, Ho FY, Yeung WF. Psychometric assessment of the full and abbreviated versions of the dysfunctional beliefs and attitudes about sleep level. 2016;12(6):821C828. Keywords: insomnia, assessment, beliefs, attitudes, sleep, cognitive-behavioral therapy, scales Intro The Dysfunctional Beliefs and Attitudes about ZD6474 Sleep Level (DBAS), which 1st appeared in Morin’s sleeping disorders treatment manual like a pre-treatment evaluation tool, has now become probably one of the most popular scales for the assessment of various sleep-related cognitions.1 Studies have shown that people with insomnia have higher DBAS scores than good sleepers. As an end result measure, several of the DBAS items are sensitive to cognitive-behavioral therapy for sleeping disorders (CBT-I) and their changes correlate with sleep improvement.2 There are different versions of the DBAS, but the most commonly used are the 30, 16, and 10 item versions. The 30-item DBAS covers 5 themes, including (1) consequences of insomnia, (2) control and predictability of sleep, (3) sleep requirement expectations, (4) causal attributions of insomnia, and (5) sleep promoting practices. However, studies have shown that only the subscales on consequences and control and predictability achieve satisfactory internal consistency. In addition, principal component analysis failed to achieve item convergence.3 For convenience of use and better psychometric properties, abbreviated versions of the DBAS have been developed. The 10-item version was created based on the items which had significant pre-post changes following CBT-I,3 while the 16-item version was based on response distribution, missing rate, item-total correlation, and lack of overlap with other items.4 Preliminary data suggested that DBAS-10 and ZD6474 DBAS-16 were valid and reliable.3,4 However, Carney and Edinger5 found that WASF1 only 2 of the 30 DBAS items possessed the ability to differentiate insomniacs from good sleepers, were sensitive to change following CBT-I, and correlated with sleep improvement, and ZD6474 the authors remained open to which DBAS version should be used. The DBAS has been translated into several languages, including Chinese. Chen et al.6 in Taiwan showed that only 2 of the 5 subscales of the 30-item version and 2 of the 4 subscales of the 16-item version had satisfactory ZD6474 internal consistency, and the factor structure was not supported by confirmatory factor analyses. To better understand the psychometric properties of the DBAS, we examined the 30, 16, 10 items versions in 312 Chinese subjects with insomnia disorder. The research questions were to find out the strengths and weaknesses of each version and whether the DBAS subscales were valid and reliable. BRIEF SUMMARY Current Knowledge/Study Rationale: The different versions of the Dysfunctional Beliefs and Attitudes about Sleep Scale (DBAS) have limited comparison and summary of the findings across studies. We aimed to examine which version and which subscales had better psychometric properties. Study Impact: The DBAS-16 possesses better internal consistency, a reproducible factor structure, strong concurrent validity, and sensitivity to change. Future studies should consider the DBAS-16 as a better option to quantify sleep-related cognitions.