Clinically meaningful changes in pain ratings: why we need special cut points in children and adolescents

Recurrent pain in children and adolescents is a pervasive healthcare issue that can only be addressed when pain and changes therein can be reliably measured. Of special importance is the assessment of clinically meaningful changes in pain since these changes provide feedback for clinicians about the trajectory of an individual patient, and guide researchers trials into the effectiveness of novel interventions. It seems self evident that the measures we use to collect pain ratings have to be validated in the sample in which they are used. Accordingly, there is a vast literature validating various pain scales (faces-pain scale, numerical rating scale [NRS], visual analog scale [VAS]), in children and adolescents [1]. Overall, these studies agree that collecting pain ratings is feasible in children 5 years and older from the age of 5 years onwards [2]. However, most of these validation studies focus on reliability (e.g., test-retest reliability), validity (e.g., correlations to parental ratings [3]), and responsitivity (e.g., increase after painful procedures, and decrease during recovery [4]). While these are important aspects of validation, they do not offer any standards by which one might interpret changes in individuals as clinically meaningful. In other words, knowing that larger changes in parental pain ratings are associated with larger changes in children’s ratings does not help to decide whether or not the treatment is successful or needs to be intensified. Cut points (e.g., decision thresholds) are the most widely used method to aid clinical decisions and classify study participant as responders or nonresponders. Before turning to the question why we need special cut points in children and adolescents, I will first summarize why we need cut points to determine clinically meaningful change and why we need special cut points for different populations.