This large-scale study of Danish children revealed that sociodemographic composition accounts for only a minor part of the regional variation in prescribing patterns for ADHD.
This study analysed registry data for all Danish children aged 5–17 years (n=813,416), to assess whether the regional prescribing patterns of ADHD medications (North, Middle, South, Capital and Zealand regions) were linked to sociodemographic composition.*
Results identified considerable regional differences in ADHD prescribing practices, with prescribing being greatest in the North (6.97% cumulative incidence proportion [CIP]) and Zealand (7.07% CIP) regions, and lowest in the South region (3.59% CIP).
The incidence of prescribing ADHD medication decreased in all regions with increasing length of parental education, particularly in the North region, where 15.5% of children from families with parental education of <10 years initiated ADHD medication versus 7.2% of those from families with parental education of 10–12 years. Furthermore, prescribing rates were greatest for disadvantaged children (i.e. children experiencing social adversity) in all regions. Overall, demographic composition explained little of the variation in ADHD prescribing practices: 3% of CIP in the North region to 13% of CIP in the Zealand region.
The regional variation observed in the prescribing of medication for ADHD in Denmark indicates that local culture plays a considerable role in the management of children with ADHD, whereas sociodemographic composition appears to have a minor influence. The unselected, nationwide cohort of Danish school-age children represents a considerable strength of this study. However, the potential influence of social adversity on being diagnosed with ADHD was not explored.
*Danish nation-wide registries contain individual-level information on health (e.g. information on dispensed prescriptions was retrieved from the Danish National Prescription Registry) and sociodemographic indicators, such as education, income, cohabitation status and region of residence. By means of an encrypted person identifier, each child was linked to associated data for their biological parents/caregivers.
Wallach-Kildemoes H, Skovgaard AM, Thielen K, et al. Social adversity and regional differences in prescribing of ADHD medication for school-age children. J Dev Behav Pediatr 2015; 36: 330-341.