Verifying the Japanese Version of Pediatric Delirium and Withdrawal Syndrome Assessment Scale: SOS-PD Validation Study for Iatrogenic Withdrawal Syndrome

Background: Iatrogenic withdrawal syndrome (IWS) poses a significant clinical challenge in pediatric intensive care units (PICUs) within Japan. Despite the existing availability of tools to assess pain and delirium, a validated instrument specifically designed for IWS has been notably absent in Japanese clinical practice. The Sophia Observation withdrawal Symptoms-Paediatric Delirium (SOS-PD) scale is globally recognized as an effective tool for IWS evaluation. To bridge this gap, this study aimed to validate the Japanese version of the SOS-PD scale. Methods: A prospective, cohort, observational study was undertaken in a single-center PICU in Japan. Participants ranged from neonates to children aged 20 years, excluding those with pre-existing neurological conditions or coma. Criterion validity was evaluated by comparing Japanese SOS-PD scale scores between a Weaning Group (WEAN) undergoing sedative/opioid tapering and a Maintenance Group (MAIN) receiving stable medication. Correlation analysis was also conducted against pediatric intensivists' observational NRS (NRSobs). Inter-rater reliability of the Japanese SOS-PD scale was assessed utilizing kappa statistics and intraclass correlation coefficient (ICC). Results: In support of criterion validity, the WEAN group demonstrated significantly higher scores in both NRSobs and the IWS component of the Japanese SOS-PD scale compared to the MAIN group (p < 0.001). A strong correlation was observed between the Japanese SOS-PD IWS component and NRSobs (r = 0.91, p < 0.001). Inter-rater reliability was also robust, with a kappa coefficient of 0.95 and an ICC of 0.98. Conclusions: The Japanese version of the SOS-PD scale exhibits strong validity and inter-rater reliability for IWS assessment within Japanese PICUs. This validated instrument can support the early detection and appropriate management of pediatric IWS in Japan, with the potential to enhance the quality of patient care.