title: Association of Attention deficit hyperactivity disorder and Kawasaki disease: a nationwide population-based cohort study.
abstract: OBJECTIVE
  The association between Kawasaki disease (KD) and Attention deficit hyperactivity disorder (ADHD) has rarely been studied. In this study, we investigated the hypothesis that KD may increase the risk of ADHD using a nationwide Taiwanese population-based claims database.
  
  
  METHODS
  Our study cohort consisted of patients who were diagnosed with KD between January 1997 and December 2005 (N = 651). For a comparison cohort, five age- and gender-matched control patients for every patient in the study cohort were selected using random sampling (N = 3255). The cumulative incidence of ADHD was 3.89/1000 (from 0.05 to 0.85) in this study. All subjects were tracked for 5 years from the date of cohort entry to identify whether or not they had developed ADHD. Cox proportional hazard regression analysis was performed to evaluate 5-year ADHD-free survival rates.
  
  
  RESULTS
  Of all patients, 83 (2.1%) developed ADHD during the 5-year follow-up period, of whom 21 (3.2%) had KD and 62 (1.9%) were in the comparison cohort. The patients with KD seemed to be at an increased risk of developing ADHD (crude hazard ratio (HR): 1.71; 95% confidence interval (CI) = 1.04-2.80; p < 0.05). However, after adjusting for gender, age, asthma, allergic rhinitis, atopic dermatitis and meningitis, the adjusted hazard ratios (AHR) of the ADHD in patients with KD showed no association with the controls (AHR: 1.59; 95% CI = 0.96-2.62; p = 0.07). We also investigated whether or not KD was a gender-dependent risk factor for ADHD, and found that male patients with KD did not have an increased risk of ADHD (AHR: 1.62; 95% CI = 0.96-2.74; p = 0.07) compared with the female patients.
  
  
  CONCLUSIONS
  The findings of this population-based study suggest that patients with KD may not have an increased risk of ADHD and whether or not there is an association between KD and ADHD remains uncertain.
authors.affiliation: Department of Pediatrics and Kawasaki Disease Center,Kaohsiung Chang Gung Memorial Hospital,Taiwan.
authors.forename: H-C
authors.identifier: http://orcid.org/0000-0002-3295-2984
authors.initials: HC
authors.lastname: Kuo
authors.affiliation: Department of Clinical Pharmacy,School of Pharmacy,Taipei Medical University,Taipei,Taiwan.
authors.forename: W-C
authors.initials: WC
authors.lastname: Chang
authors.affiliation: Master Program for Clinical Pharmacogenomics and Pharmacoproteomics,School of Pharmacy,Taipei Medical University,Taipei,Taiwan.
authors.forename: L-J
authors.initials: LJ
authors.lastname: Wang
authors.affiliation: Department of Pharmacy,Taipei Medical University-Wanfang Hospital,Taipei,Taiwan.
authors.forename: S-C
authors.initials: SC
authors.lastname: Li
authors.affiliation: Department of Healthcare Management,YuanPei University of Medical Technology,HsinChu,Taiwan.
authors.forename: W-P
authors.initials: WP
authors.lastname: Chang
mesh_terms: D001289:Attention Deficit Disorder with Hyperactivity / Q000150:complications / Q000453:epidemiology*; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009080:Mucocutaneous Lymph Node Syndrome / Q000150:complications / Q000453:epidemiology*; D016016:Proportional Hazards Models; D012307:Risk Factors
keywords: ADHD; Kawasaki disease; population-based study