Reliability and validity of the Time-Sensitive ADHD Symptom Scale in adults

ObjectivesThe objective of this study was to examine the psychometric properties of the Time-Sensitive ADHD Symptom Scale (TASS) to evaluate change of attention-deficit/hyperactivity disorder (ADHD) symptoms over the course of a day in adults.MethodsEighty adults with ADHD participated in 1 or 2 visits, 1 to 9 weeks apart. At each visit, participants completed the TASS followed by raters administering the ADHD Rating Scale (ADHD-RS). Additional TASS and ADHD-RS ratings were completed 2 to 6 hours after each visit via telephone. Internal consistency of TASS items was assessed by Cronbach's α. Convergent validity of TASS and ADHD-RS total mean item scores was assessed using Pearson's correlation coefficients. κ correlations were calculated to assess item-by-item reliability between TASS and ADHD-RS items.ResultsInternal consistency of TASS items was high, with an overall Cronbach's α coefficient of .93. The Pearson's correlation coefficient between the TASS and ADHD-RS was significant for all visits (r = 0.70, P < .0001). There was moderate agreement between individual items on the TASS and ADHD-RS, with significant κ coefficients for almost all items (P < .05).DiscussionThe TASS showed high internal consistency and concurrent validity with the clinician-administered ADHD-RS and is a valid and reliable scale for measuring change in ADHD symptoms over the course of a day in adults.