Italian Diagnostic Adaptive Behavior Scale: Reliability and diagnostic accuracy compared with the Vineland-II.

Background: The Diagnostic Adaptive Behavior Scale (DABS) is a short scale with excellent properties to assess the conceptual, social, and practical adaptive behavior domains for the diagnosis of intellectual disability (ID) in individuals aged 4-21 years.

Aims: Investigate the test-retest and inter-respondent reliability of the Italian adaptation of the DABS, verify its diagnostic accuracy in identifying individuals with ID and excluding individuals with typical development (TD), and compare its psychometric properties to those of the Vineland-II.

Methods: Test-retest reliability: The same respondent completed the Italian DABS for the same assessed person at two separate times (n = 71). Inter-respondent reliability: Two respondents for the same assessed person completed the Italian DABS independently (n = 57). Diagnostic accuracy: The same respondent completed the Italian DABS and Vineland-II for the same assessed person (n = 378; 50 % ID, 50 % TD).

Results: Italian DABS test-retest and inter-respondent correlation coefficients were excellent. Italian DABS sensitivity was 86 % and specificity was 99 %, Italian DABS Areas Under the ROC Curves were excellent (or good, practical skill domain), and comparable to the results reported for the Vineland-II.

Conclusions: The Italian DABS is an excellent measure to evaluate the adaptive behavior for ID diagnosis; it is comparable to the Vineland-II but being shorter, the Italian DABS requires less time to administer.