Healthcare use in individuals with and without attention-deficit/hyperactivity disorder: A population-based...

Individuals with Attention-Deficit/Hyperactivity Disorder (ADHD) experienced worsening symptoms during the COVID-19 pandemic resulting in increased demand for healthcare services. However, it is unclear how those with and without ADHD utilized these services during the COVID-19 pandemic. This study examined healthcare utilization among individuals with and without ADHD and as a secondary objective, investigated these trends among female and male subgroups, from April 1, 2014-March 31, 2023. We conducted a population-based longitudinal retrospective cohort study among ADHD cases identified using a validated algorithm, and controls from Ontario, Canada over the same study period. We matched ADHD cases 1:1 to controls by sex, birth year, and geographical area. Outcomes were number of outpatient visits per person per fiscal year to family physicians, for mental health and to emergency departments, stratified by sex and age group over the follow-up period. Crude visit rate differences between sex-specific cases and controls were calculated with 95% confidence intervals (CI). We matched 427 716 ADHD cases to 427 716 controls. ADHD cases were 163 528 ≤ 17 years (32% female), and 264 188 adults (52% female). From 2013-2024, where March 17, 2020 marked the onset of the COVID-19 pandemic, females aged 1-17 years with ADHD appeared to have higher visit rate differences to family physicians, emergency departments, and increased mental health services, relative to their controls, particularly in 2020 [2.66 (95% CI: 2.65-2.68)]. In the same year, males with ADHD still had a higher mental health visit rate difference, [2.02 (95% CI: 2.01-2.02)] in 2020, but lower than that observed in females. Adult females with ADHD had the highest mental health visit rate difference in 2020 [5.09 (95% CI: 5.07-5.11)] and males with ADHD had 4.41 (95% CI: 4.40-4.43). These higher service utilization differences likely reflected greater health needs among females with ADHD while males underutilized these services.