Long-term clinical and cost-effectiveness of a therapist-supported online remote behavioural intervention for tics in children and adolescents: extended 12- and 18-month follow-up of a single-blind randomised controlled trial.

Background: Little is known about the long-term effectiveness of behavioural therapy for tics. We aimed to assess the long-term clinical and cost-effectiveness of online therapist-supported exposure and response prevention (ERP) therapy for tics 12 and 18 months after treatment initiation.

Methods: ORBIT (online remote behavioural intervention for tics) was a two-arm (1:1 ratio), superiority, single-blind, multicentre randomised controlled trial comparing online ERP for tics with online psychoeducation. The trial was conducted across two Child and Adolescent Mental Health Services in England. Participants were recruited from these two sites, across other clinics in England, or by self-referral. This study was a naturalistic follow-up of participants at 12- and 18-month postrandomisation. Participants were permitted to use alternative treatments recommended by their clinician. The key outcome was the Yale Global Tic Severity Scale Total Tic Severity Score (YGTSS-TTSS). A full economic evaluation was conducted. Registrations are ISRCTN (ISRCTN70758207); ClinicalTrials.gov (NCT03483493).

Results: Two hundred and twenty-four participants were enrolled: 112 to ERP and 112 to psychoeducation. The sample was predominately male (177; 79%) and of white ethnicity (195; 87%). The ERP intervention reduced baseline YGTSS-TTSS by 2.64 points (95% CI: -4.48 to -0.79) with an effect size of -0.36 (95% CI: -0.61 to -0.11) after 12 months and by 2.01 points (95% CI: -3.86 to -0.15) with an effect size of -0.27 (95% CI -0.52 to -0.02) after 18 months, compared with psychoeducation. Very few participants (<10%) started new tic treatment during follow-up. The cost difference in ERP compared with psychoeducation was £304.94 (-139.41 to 749.29). At 18 months, the cost per QALY gained was £16,708 for ERP compared with psychoeducation.

Conclusions: Remotely delivered online ERP is a clinical and cost-effective intervention with durable benefits extending for up to 18 months. This represents an efficient public mental health approach to increase access to behavioural therapy and improve outcomes for tics.