Development and Validation of a Practical Tool for Assessing Acute Pain in the Pediatric Population With Down Syndrome (ANDREAS): A Study Protocol.

Background Down syndrome (DS) is one of the most common chromosomal anomalies, affecting a substantial number of newborns globally. Pediatric patients with DS face a range of health challenges, including complex and often underrecognized pain experiences. These children may exhibit atypical responses to pain, such as reduced verbal expression, behavioral changes (e.g., freezing), or lower pain thresholds, that can render conventional pain assessment strategies insufficient. Consequently, there is a critical need for multidimensional tools specifically tailored to the characteristics of this vulnerable population. This study aims to develop and validate a novel mixed-methods instrument - the ANDREAS tool - designed to accurately assess acute pain in children with DS by integrating behavioral observations with self-report measures, where feasible. Methods A mixed-methods approach will be employed to adapt a pain assessment scale suitable for children with DS, combining behavioral observations with self-reported measures when possible. Pain-related behaviors will be identified through an extensive literature review and focus group discussions involving researchers, parents, and healthcare professionals. Additional methodological components will include defined randomization procedures for participant selection, clear inclusion and exclusion criteria, a standardized venipuncture protocol to induce pain, and a tailored training program for assessors to ensure methodological rigor. The resulting instrument, ANDREAS, will undergo validation using exploratory factor analysis and internal consistency testing (Cronbach's alpha). Results The study is expected to yield a validated tool capable of capturing both the presence and severity of acute pain in pediatric patients with DS. Key behavioral indicators, such as freezing, defined as the absence of movement for at least five seconds during a painful stimulus, will be operationalized and assessed using a structured 0-4 rating scale. The integration of behavioral and self-report data is anticipated to enhance the sensitivity and specificity of pain detection in this population. Conclusions The ANDREAS instrument is expected to provide a reliable, valid, and clinically meaningful method for assessing acute pain in children with DS. By combining behavioral observations with self-report, it introduces a novel, multidimensional approach that may improve the accuracy of pain evaluation and inform more effective clinical management strategies. Future research will focus on further validating the instrument's psychometric properties and exploring its use across diverse clinical settings.