Tourette syndrome increases risk of bone fractures: a population-based cohort study

This study assesses the risk of fractures among children with Tourette syndrome (TS), and identifies the effects of comorbidities and antipsychotics. We randomly sampled the claims data of 1 million enrollees in the National Health Insurance program of Taiwan, and identified 1258 children with TS diagnosed between 2000 and 2010. Additionally, 12,580 children without TS who were frequency matched for sex, age, residential area, parental occupation, and index year were identified for comparison. The children's cases were followed until December 31, 2010, or censored to ascertain incident fractures cases and associations with comorbidities of attention-deficit/hyperactivity disorder (ADHD) or obsessive-compulsive disorder (OCD) and treatments with antipsychotics, antidepressants, or clonidine. The TS cohort had a 1.27-fold higher incidence of fractures than did the comparison cohort (190.37 vs. 149.94 per 10,000 person-years), with an adjusted hazard ratio (HR) of 1.28 [95% confidence interval (CI) 1.06-1.55] based on multivariable Cox regression analysis. This increased risk of fractures was apparent for fractures of the skull, neck, and spine. Comorbid ADHD and OCD did not result in an additional risk of fractures. The children without both ADHD and OCD were also at a higher risk of fractures, indicating that TS alone increases the risk of fractures. The children taking antipsychotics had a reduced risk of fractures, and the adjusted HR decreased to 1.17 (95% CI 0.90-1.52). Children with TS have an increased risk of fractures. ADHD and OCD do not increase the risk further.