UNLABELLED: This study has the objective to translate the Cornell Assessment of Pediatric Delirium (CAPD) into Indonesian and evaluate the psychometric properties and diagnostic accuracy of the Indonesian version of the CAPD (I-CAPD) in identifying delirium in critically ill children. This prospective methodological study was conducted between January and April 2024 in a 6-bed pediatric intensive care unit (PICU). In total, 90 children aged 0-18 years hospitalized in the PICU were included. Bedside nurses administered the I-CAPD every shift, while delirium diagnoses were confirmed by a psychiatrist by using the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria. A receiver operating characteristic (ROC) curve analysis was conducted to examine the sensitivity and specificity of the I-CAPD. The mean age was 8 years, with 53% being girl. According to DSM-5 criteria, 55.6% of the children had PICU delirium. Cronbach's α and interclass correlation coefficient for the I-CAPD were 0.94 and 0.94, respectively. The I-CAPD exhibited a single-factor structure accounting for 72% of the total variance. The I-CAPD was significantly associated with pain assessments (r = 0.32, P <
0.001). The ROC curve analysis indicated an optimal cutoff of ≥ 9, with the sensitivity, specificity, and area under curve of 92%, 93%, and 0.96, respectively. CONCLUSION: The I-CAPD demonstrates reliable psychometric properties and diagnostic accuracy for detecting delirium in critically ill children. Future studies should explore the impact of routine I-CAPD screening on clinical outcomes and targeted interventions for pediatric delirium. WHAT IS KNOWN: • Delirium in pediatric intensive care units (PICUs) is prevalent and associated with adverse outcomes, yet its diagnosis remains challenging, particularly in low-resource settings. • The Cornell Assessment of Pediatric Delirium (CAPD) has been validated in multiple languages and contexts but has not been adapted for use in Indonesian-speaking populations. WHAT IS NEW: • This study demonstrates the successful translation and psychometric evaluation of the Indonesian version of the CAPD (I-CAPD), confirming its reliability and validity in identifying delirium in critically ill Indonesian children. • The I-CAPD provides a standardized tool with high diagnostic accuracy (sensitivity: 92%
specificity: 93%) for routine delirium screening in Indonesian PICUs.