Behavioural Interventions and Botulinum Toxin Injections for Drooling, Swallowing, Feeding, and Oral-Motor Outcomes in Children: A Domain-Specific Systematic Review and Meta-Analysis of Randomised Controlled Trials

Objective: Despite increasing use of behavioural interventions in paediatric swallowing and feeding care, the evidence base remains limited and difficult to interpret due to small sample sizes, heterogeneous interventions, diverse outcome measures, and variability in study populations. This review and meta-analysis, therefore, aimed to evaluate the effects of behavioural interventions and botulinum toxin injections on drooling, swallowing, feeding, and oral-motor outcomes in children, based exclusively on randomised controlled trials (RCTs). Methods: Systematic searches were conducted in CINAHL, Embase, and PubMed to identify RCTs. Pharmacological and surgical interventions were excluded, except for botulinum toxin injections, which were analysed as a distinct intervention category given their widespread clinical use in paediatric drooling management. Methodological quality was assessed using the Revised Cochrane Risk of Bias tool (RoB 2). Random-effects meta-analyses were performed, with prediction intervals calculated to account for between-study heterogeneity and to assess the expected range of effects in comparable future studies. Results: Twenty-eight studies were included. Behavioural interventions demonstrated moderate-to-large effects on oral-motor outcomes, whereas botulinum toxin injections demonstrated the strongest effects on drooling. Outcomes measured using multi-item caregiver-reported tools showed larger effects. No significant effects were observed for swallowing or feeding outcomes. Effect sizes varied by age, outcome measure, and respondent type, indicating systematic sources of variation in intervention effects. Prediction intervals indicated substantial clinical and methodological variability, suggesting that intervention effects are context-dependent and not consistently generalisable across populations and settings. Conclusions: Intervention effectiveness in paediatric swallowing and feeding is domain-specific, with consistent benefits observed for drooling and oral-motor outcomes but not for swallowing or feeding. Outcomes are strongly influenced by the measurement approach. High-quality, standardised RCTs targeting specific functional domains are needed to strengthen the evidence base and inform clinical decision making. However, substantial variability in intervention effects across studies suggests that treatment effectiveness may vary with population characteristics, intervention approaches, and outcome measurement methods.