Review of Studies on Incremental Validity of Assessment Measures Used in Psychological Assessment of Attention-Deficit Hyperactivity Disorder

Few studies have summarized the literature relevant to the incremental validity of tools and procedures for the assessment of attention-deficit hyperactivity disorder (ADHD). The current project reviewed such studies published in the prior 18 years. Results from studies on the incremental validity of measures used in the assessment of ADHD were reviewed. Measures included symptom reports, clinical interviews, behavioral observation, continuous performance and other psychomotor tasks, intelligence tests, and measures of executive function. Twenty-nine published studies and two reviews were identified from 2004 to 2022. Incremental validity was determined using various statistics including R-2, classification metrics, odds ratios, and post-test probabilities. Findings suggest that symptom reports from a collateral source and continuous performance test measures have incremental validity over self-reports and clinical interviews. Measures of intellectual and executive functioning did not show incremental validity in the diagnosis of ADHD. Findings are relevant to the practitioner, as they bear on the optimization of both the cost-effectiveness and the diagnostic accuracy of combined procedures in the assessment of ADHD.