Digitally augmented, parent-led CBT versus treatment as usual for child anxiety problems in child mental health services in England and Northern Ireland: a pragmatic, non-inferiority, clinical effectiveness and cost-effectiveness randomised controlled trial.

Background: Anxiety problems are common in children, yet few affected children access evidence-based treatment. Digitally augmented psychological therapies bring potential to increase availability of effective help for children with mental health problems. This study aimed to establish whether therapist-supported, digitally augmented, parent-led cognitive behavioural therapy (CBT) could increase the efficiency of treatment without compromising clinical effectiveness and acceptability.

Methods: We conducted a pragmatic, unblinded, two-arm, multisite, randomised controlled non-inferiority trial to evaluate the clinical effectiveness and cost-effectiveness of therapist-supported, parent-led CBT using the Online Support and Intervention (OSI) for child anxiety platform compared with treatment as usual for child (aged 5-12 years) anxiety problems in 34 Child and Adolescent Mental Health Services in England and Northern Ireland. We examined acceptability of OSI plus therapist support via qualitative interviews. Participants were randomly assigned (1:1) to OSI plus therapist support or treatment as usual, minimised by child age, gender, service type, and baseline child anxiety interference. Outcomes were assessed at week 14 and week 26 after randomisation. The primary clinical outcome was parent-reported interference caused by child anxiety at week 26 assessment, using the Child Anxiety Impact Scale-parent report (CAIS-P). The primary measure of health economic effect was quality-adjusted life-years (QALYs). Outcome analyses were conducted blind in the intention-to-treat (ITT) population with a standardised non-inferiority margin of 0·33 for clinical analyses. The trial was registered with ISRCTN, 12890382.

Findings: Between Dec 5, 2020, and Aug 3, 2022, 706 families (706 children and their parents or carers) were referred to the study information. 444 families were enrolled. Parents reported 255 (58%) child participants' gender to be female, 184 (41%) male, three (<1%) other, and one (<1%) preferred not to report their child's gender. 400 (90%) children were White and the mean age was 9·20 years (SD 1·79). 85% of families for whom clinicians provided information in the treatment as usual group received CBT. OSI plus therapist support was non-inferior for parent-reported anxiety interference on the CAIS-P (SMD 0·01, 95% CI -0·15 to 0·17; p<0·0001) and all secondary outcomes. The mean difference in QALYs across trial arms approximated to zero, and OSI plus therapist support was associated with lower costs than treatment as usual. OSI plus therapist support was likely to be cost effective under certain scenarios, but uncertainty was high. OSI plus therapist support acceptability was good. No serious adverse events were reported.

Interpretation: Digitally augmented intervention brought promising savings without compromising outcomes and as such presents a valuable tool for increasing access to psychological therapies and meeting the demand for treatment of child anxiety problems.

Funding: Department for Health and Social Care and United Kingdom Research and Innovation Research Grant, National Institute for Health and Care (NIHR) Research Policy Research Programme, Oxford and Thames Valley NIHR Applied Research Collaboration, Oxford Health NIHR Biomedical Research Centre.