Internet-Delivered Exposure and Response Prevention for Pediatric Tourette Syndrome: 12-Month Follow-Up of a Randomized Clinical Trial.

IMPORTANCE: Behavior therapy is a recommended intervention for Tourette syndrome (TS) and chronic tic disorder (CTD), but availability is limited and long-term effects are uncertain.

OBJECTIVE: To investigate the long-term efficacy and cost-effectiveness of therapist-supported, internet-delivered exposure and response prevention (ERP) vs psychoeducation for youths with TS or CTD.

DESIGN, SETTING, AND PARTICIPANTS: This 12-month controlled follow-up of a parallel group, superiority randomized clinical trial was conducted at a research clinic in Stockholm, Sweden, with nationwide recruitment. In total, 221 participants aged 9 to 17 years with TS or CTD were enrolled between April 26, 2019, and April 9, 2021, of whom 208 (94%) provided 12-month follow-up data. Final follow-up data were collected on June 29, 2022. Outcome assessors were masked to treatment allocation throughout the study.

INTERVENTIONS: A total of 111 participants were originally randomly allocated to 10 weeks of therapist-supported, internet-delivered ERP and 110 participants to therapist-supported, internet-delivered psychoeducation.

MAIN OUTCOMES AND MEASURES: The primary outcome was within-group change in tic severity, measured by the Total Tic Severity Score of the Yale Global Tic Severity Scale (YGTSS-TTSS), from the 3-month follow-up to the 12-month follow-up. Treatment response was defined as 1 (very much improved) or 2 (much improved) on the Clinical Global Impression-Improvement scale. Analyses were intention-to-treat and followed the plan prespecified in the published study protocol. A health economic evaluation was performed from 3 perspectives: health care organization (including direct costs for treatment provided in the study), health care sector (additionally including health care resource use outside of the study), and societal (additionally including costs beyond health care [eg, parent's absenteeism from work]).

RESULTS: In total, 221 participants were recruited (mean [SD] age, 12.1 [2.3] years; 152 [69%] male). According to the YGTSS-TTSS, there were no statistically significant changes in tic severity from the 3-month to the 12-month follow-up in either group (ERP coefficient, -0.52 [95% CI, -1.26 to 0.21]; P = .16; psychoeducation coefficient, 0.00 [95% CI, -0.78 to 0.78]; P > .99). A secondary analysis including all assessment points (baseline to 12-month follow-up) showed no statistically significant between-group difference in tic severity from baseline to the 12-month follow-up (coefficient, -0.38 [95% CI, -1.11 to 0.35]; P = .30). Treatment response rates were similar in both groups (55% in ERP and 50% in psychoeducation; odds ratio, 1.25 [95% CI, 0.73-2.16]; P = .42) at the 12-month follow-up. The health economic evaluation showed that, from a health care sector perspective, ERP produced more quality-adjusted life years (0.01 [95% CI, -0.01 to 0.03]) and lower costs (adjusted mean difference -$84.48 [95% CI, -$440.20 to $977.60]) than psychoeducation at the 12-month follow-up. From the health care organization and societal perspectives, ERP produced more quality-adjusted life years at higher costs, with 65% to 78% probability of ERP being cost-effective compared with psychoeducation when using a willingness-to-pay threshold of US $79 000.

CONCLUSIONS AND RELEVANCE: There were no statistically significant changes in tic severity from the 3-month through to the 12-month follow-up in either group. The ERP intervention was not superior to psychoeducation at any time point. While ERP was not superior to psychoeducation alone in reducing tic severity at the end of the follow-up period, ERP is recommended for clinical implementation due to its likely cost-effectiveness and support from previous literature.

TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT03916055.