Defining a minimal clinically important difference for the Vanderbilt ADHD Parent Rating Scale in children with...

Attention-deficit/hyperactivity disorder (ADHD) is a prevalent neurodevelopmental condition in children and adolescents that poses substantial challenges to health, functioning, and well-being. This study aimed to estimate the minimal clinically important difference (MCID) for the Chinese version of the Vanderbilt ADHD Parent Rating Scale (VAFPRS) and its key score domains using anchor-based and distribution-based methods.

In this multicenter prospective observational study, 99 children aged 4-17 years who were diagnosed with ADHD were recruited from four tertiary hospitals in China. Caregivers completed the VAFPRS at baseline and follow-up and the Clinical Global Impression-Improvement (CGI-I) scale at follow-up. MCID values were estimated using the anchor-based median change method, the receiver operating characteristic (ROC) curve method, and the distribution-based 0.5 standard deviation (SD) method.

A total of 81 patients completed the follow-up assessment. CGI-I scores were significantly correlated with changes in the total VAFPRS score, core symptoms, inattention, and hyperactivity/impulsivity (r = 0.38-0.43, all p < 0.01). The corresponding anchor-based median MCID estimates were - 8, -5, - 2, and - 3, respectively. ROC curve analysis yielded lower thresholds for these domains (- 3.5, - 2.5, - 1.5, and - 2.5), with acceptable discrimination (AUC ≥ 0.70) for identifying improvement.

This study estimated MCID values for the Chinese VAFPRS in children and adolescents with ADHD. Anchor-based median estimates derived from the minimally improved CGI-I group were - 8 for the total score, - 5 for core symptoms, - 2 for inattention, and - 3 for hyperactivity/impulsivity. ROC-derived thresholds were lower and may provide complementary classification cutoffs for identifying improvement status.

Not applicable.