Design of a Multisite Study Assessing the Impact of Tic Disorders on Individuals, Families, and Communities

Abstract

Background: Tic disorders, including Tourette syndrome, are complex, multisymptom diseases, yet the impact of these disorders on affected children, families, and communities is not well understood.

Methods: To improve the understanding of the impacts of Tourette syndrome, two research groups conducted independent cross-sectional studies using qualitative and quantitative measures. They focused on similar themes, but distinct scientific objectives, and the sites collaborated to align methods of independent research proposals with the aim of increasing the analyzable sample size.

Results: Site 1 (University of Rochester) was a Pediatric Neurology referral center. Site 2 (University of South Florida) was a Child Psychiatry referral center. A total of 205 children with tic disorders were enrolled from both studies. The University of Rochester also enrolled 100 control children in order to clearly isolate impacts of Tourette syndrome distinct from those occurring in the general population. The majority of children with tic disorders (n = 191, 93.1%) had Tourette syndrome, the primary population targeted for these studies. Children with Tourette syndrome were similar across sites in terms of tic severity and the occurrence of comorbid conditions. The occurrence of psychiatric comorbidities in the control group was comparable with that in the general pediatric population of the United States, making this a well-justified comparison group.

Conclusions: Through collaboration, two sites conducting independent research developed convergent research methods to enable pooling of data, and by extension increased power, for future analyses. This method of collaboration is a novel model for future epidemiological research of tic disorders.

Keywords: Tourette syndrome; epidemiology; research design; research methods; tics.

Figure 1. Participant Recruitment and Eligibility

Abbreviations CTD: chronic tic disorder DSM-IV-TR: Diagnostic and Statistical Manual for Mental Disorders, 4^th edition, text revision1 TD-NOS: Tic disorder not otherwise specified TS: Tourette syndrome

Figure 2. Triage Protocol

Abbreviations DISC-IV: Diagnostic Interview Schedule for Children – Fourth edition (DISC-IV) MAVRIC-P: Measure of Anger, Violence, and Rage in Children, parent-report PI: Principal investigator