Incidence and risk of attention-deficit hyperactivity disorder in children with amblyopia: A nationwide cohort study

ImportanceThe association between visual deficits and attention disorders has been reported but remains unproven. BackgroundThe objective of this study was to evaluate the risk of attention-deficit hyperactivity disorder (ADHD) in children with amblyopia. DesignPopulation-based, cohort study. ParticipantsThe dataset from the Taiwan National Health Insurance Research Database in 2000 to 2010. MethodsA total of 6817 patients aged <18years with newly diagnosed amblyopia were identified. Four age- and sex-matched controls without amblyopia were included for each patient, that is, 27268 controls. Main Outcome MeasuresThe primary outcome was the risk of ADHD. The secondary outcomes were age at ADHD onset and use of ADHD medication. ResultsDuring a mean observation period of 7.18years, the incidence of ADHD per 1000 person-years was 7.02 in the amblyopia group and 4.61 in the control group (P < 0.0001). The ADHD risk in the amblyopia group was 1.81 times that in the control group (hazard ratio 1.81; 95% confidence interval 1.59-2.06). After stratification by amblyopia subtype, the greatest risk was in the deprivation type (hazard ratio 2.14; 95% confidence interval 1.56-2.92) followed by the strabismic (hazard ratio 2.09; 95% confidence interval 1.15-3.79) and refractive (hazard ratio 1.76; 95% confidence interval 1.54-2.02) types. Age at ADHD onset was younger in the amblyopia group (median 8.14 vs 8.45years; P =0.0096). The average duration of neuropsychiatric medication use was comparable between groups (P =0.98). Conclusions and RelevanceThe ADHD risk is higher in children with amblyopia.