Physiological-behavioural discordance in paediatric perioperative anxiety assessment: a scoping review protocol.

introductionPreoperative anxiety in children is a common problem in paediatric surgical care. In current practice, anxiety is assessed mainly by behavioural rating scales, of which the modified Yale Preoperative Anxiety Scale (mYPAS) is the most widely used. However, behavioural observation may not capture children whose outward behaviour stays calm while their autonomic stress response is still high. This mismatch between visible behaviour and underlying physiology can lead to under-recognition of anxiety and may explain the modest correlations reported between behavioural scores and physiological markers in children. The aim of this scoping review is to map the published evidence on physiological-behavioural discordance during paediatric perioperative anxiety and to identify methodological gaps that future multimodal assessment research will need to address. METHODS AND ANALYSIS: The review will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) extension for Scoping Reviews reporting guideline and the Joanna Briggs Institute methodology for scoping reviews. We will search PubMed/MEDLINE, Embase, Web of Science Core Collection, CINAHL Complete and PsycINFO from database inception to 31 December 2025. Eligible studies will recruit children aged 0 to 18 years in perioperative or analogous procedural settings, and will report both a behavioural anxiety measure (such as mYPAS, mYPAS-SF, State-Trait Anxiety Inventory for Children (STAI-C)) and at least one concurrent physiological stress indicator (heart rate variability, salivary cortisol, salivary alpha-amylase, electrodermal activity, heart rate or intraoperative nociception indices). The primary analysis will focus on perioperative anaesthesia induction. Procedural sedation, venipuncture and dental contexts will be analysed as a separate secondary stratum because their stress profile is not the same as anaesthesia induction. Two reviewers will screen and extract data independently. Premedication exposure, regular home psychoactive medication use (including cannabinoids) and the time gap between behavioural and physiological sampling will be extracted as prespecified confounders. Findings will be synthesised narratively following the Synthesis Without Meta-analysis reporting guideline. ETHICS AND DISSEMINATION: Ethical approval is not required because the review uses only published literature. Results will be submitted to a peer-reviewed journal and presented at paediatric anaesthesia conferences. A plain-language summary will be co-produced with parent advisors.