Practical applications of brief screening questionnaires for autism spectrum disorder in a psychiatry outpatient setting.

OBJECTIVES This study was designed to examine the diagnostic performance of the social and communication disorders checklist (SCDC) and strength and difficulties questionnaire (SDQ) to detect autism spectrum conditions (ASC), along with the social responsiveness scale-second edition (SRS-2) as reference, in a psychiatry outpatient setting. METHODS We translated the SCDC into Japanese since its Japanese version was unavailable. We examined its test-retest reliability as well as the internal consistency reliability and diagnostic performance of the three questionnaires among 41 Japanese psychiatric outpatients, using the best-estimate diagnosis of ASC based on the diagnostic interview for social and communication disorders, as a gold standard. RESULTS The test-retest reliability was high for the SCDC. Although the internal consistency reliability was high for the SCDC and SRS-2, that was low for the prosocial and peer problem subscales of the SDQ. The performance of the SCDC, SDQ, and SRS-2 to detect ASC was moderate: the area under the ROC curve of 0.78, 0.78, and 0.84, respectively. CONCLUSIONS Although questionnaires to detect ASC, including the three examined, generally have only moderate performance in this setting, these can be successfully applied to high-risk populations such as psychiatry outpatients, when multi-level rather than dichotomous likelihood ratios are used.