Preliminary Psychometric Findings and Feasibility of the Diagnostic Interview for Adolescents and Adults With Intellectual Disability ( DIAAID ): An Interview Schedule of Mental Disorders

Background This report describes the preliminary psychometric evaluation of the Diagnostic Interview for Adolescents and Adults with Intellectual Disability: An interview schedule of mental disorders (DIAAID), an accessible structured interview for individuals with intellectual disability. Method We examined test–retest reliability, inter‐rater reliability, and concordance between direct and other‐informant reports. Results Intraclass correlations (CCs) for test–retest ranged from good to poor (ICC 0.79–< 0.50). ICCs for inter‐rater reliability revealed excellent to moderate reliability between two independent raters (ICC 1.00–0.65). Percent agreement was high for positive and negative diagnoses between adolescent/adult participants (AAPs) and study partner participants (SPPs) (87.7%–100%) and between two raters of the same direct‐report interview (90.9–100). Although SPPs endorsed more symptoms than AAPs, AAPs endorsed some that SPPs did not, with poor agreement between direct and informant reports (ICC −0.01 to 0.30). Conclusion Preliminary psychometric findings are promising though not compelling. The direct report detects symptoms not noted by the caregiver.