Supplementary Material for: Consumption of sugar-sweetened beverages before 2 years of age and attention-deficit/hyperactivity disorder

Introduction: This study examined the association between sugar-sweetened beverage consumption before the first 24 months of life and attention-deficit/hyperactivity disorder (ADHD).
Methods: A population administrative cohort study was conducted in Korea (2008–2019) using linked national insurance data and a health screening survey. The cohort included 25,305 children in the exposed group with high sugar-sweetened beverage drinks (≥200 ml) and 339,931 in the reference groups (<200 ml) at 24 months of age. The primary outcome was the development of ADHD based on the International Classification of Disease (ICD) codes. Cox proportional model was used to identify the association between sugar-sweetened beverage consumption during early childhood and the later development of ADHD while controlling for multiple risk factors.
Results: Over a mean follow-up period of 9.2 years, the incidence rates of ADHD were 29.6 and 23.8 per 10,000 person-years (PY) in the exposed and reference groups, respectively. Compared with the reference group, children consuming high-sugar drinks were at an increased risk of ADHD (adjusted hazard ratio [aHR] 1.17, 95% confidence interval [CI] 1.08–1.27). These associations remained significant even after applying alternative ADHD definitions or adjusting for confounding variables.
Conclusion: Children who consume sweetened beverages during early childhood are at increased risk of developing ADHD later in life.