Attention-Deficit/Hyperactivity Disorder Is Associated With Increased Rates of Childhood Infectious Diseases: A Population-Based Case-Control Study

Objective: Infectious diseases (IDs) pose a heavy burden on children. An association between pediatric attention-deficit/hyperactivity disorder (ADHD) and specific IDs has been documented. Our objective was to test the possibility that ADHD is associated with increased likelihood for pediatric IDs at large. Method: A population-based case-control study was conducted using Electronic Medical Records (EMRs) of a national Health Maintenance Organization, Leumit Health Services (LHS). ICD-9/10 criteria were used for all diagnoses. The study population consisted of all children and adolescents (aged 5-18 years), members of LHS between January 1, 2006-June 30, 2021. Case patients met International Classification of Diseases (ICD-9/10) criteria for ADHD. Controls included randomly selected persons without ADHD (2:1 ratio), matched individually by demographic indices. The EMRs retrieved 3 exposure categories: pediatric ID, anti-infective medications use, and number of physician visits. The study was approved by the review board of Shamir Medical Center and the Research Committee of LHS. Results: Cases patients comprised 18,756 participants, with a mean age of 8.3 ± 2.6 years and a male/female ratio of 63%:37%. Matched controls comprised 37,512 participants, with a mean age of 8.3 ± 2.6 years and a male/female ratio of 63%:37%. Demographic variables were similar between the groups. The rates of all IDs were significantly higher in participants with ADHD than in controls and were not restricted to a single body system, including acute respiratory infection (OR = 1.4, 95% CI = 1.3-1.4, p < .001), acute gastroenteritis (OR = 1.3,95% CI 1.3-1.4, p < .001), salmonellosis (OR = 2.8, 95% CI = 2.3-3.5, p < .001), and urinary tract infection (OR = 1.3, 95% CI = 1.2-1.4, p < .001). All anti-infective agents were prescribed significantly more often to children with ADHD. There were significantly higher rates of physician visits for participants with ADHD. Conclusion: Study findings suggest an association between ID and pediatric ADHD Health care providers should be aware of this potential association. Clinical trial registration information: The Health and Economic Impact of Treated and Untreated ADHD; https://www.shamir.org/; 005-18-LEU.