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

Abstract

Importance: The association between visual deficits and attention disorders has been reported but remains unproven.

Background: The objective of this study was to evaluate the risk of attention-deficit hyperactivity disorder (ADHD) in children with amblyopia.

Design: Population-based, cohort study.

Participants: The dataset from the Taiwan National Health Insurance Research Database in 2000 to 2010.

Methods: A total of 6817 patients aged <18 years 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 measures: The primary outcome was the risk of ADHD. The secondary outcomes were age at ADHD onset and use of ADHD medication.

Results: During a mean observation period of 7.18 years, 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 8.45 years; P = 0.0096). The average duration of neuropsychiatric medication use was comparable between groups (P = 0.98).

Conclusions and relevance: The ADHD risk is higher in children with amblyopia.

Keywords: amblyopia; attention-deficit hyperactivity disorder; children; incidence.