It has been hypothesised that ADHD could be associated with an increased risk of unintentional physical injuries (UPIs), which in turn may be linked to increased mortality. Several studies have examined the association between ADHD and UPIs in children and adolescents, and even after controlling for comorbidities, the extent of this association remains unclear. The purpose of this study was to assess the risk of UPIs in children and adolescents with and without ADHD, and to determine whether patients treated with ADHD-approved medication were at a lower risk of UPIs.
This was a systematic review with meta-analyses which pooled data from both published and unpublished studies that contrasted the risk of UPIs in children and adolescents with ADHD with those without ADHD (‘risk’ meta-analysis), and the risk of UPIs in individuals with ADHD while taking and not taking medication (‘medication’ meta-analysis). Any type of empirical study was included in the analyses, regardless of study design, temporality, setting or risk of injury, while in order to prevent bias, studies that did not control for gender differences between individuals with and without ADHD were excluded from the analyses.
A total of 220 full-text articles were assessed for eligibility; 30 studies were used in the risk meta-analysis and 5 studies were used in the medication meta-analysis. In total, 350,938 (based on studies presenting odds ratios [ORs]) and 20,363 (based on studies presenting hazard ratios [HRs]) children or adolescents with ADHD were included in the risk meta-analysis, and 13,254 were included in the medication analysis. For comparison, 4,055,620 (based on ORs) and 901,891 (based on HRs) children and adolescents without ADHD were included in the risk meta-analysis.
Both the OR- and HR-based risk meta-analyses indicated a significantly higher risk of UPIs in children or adolescents with ADHD compared with those without ADHD, with significant heterogeneity between studies (OR-based meta-analysis: OR=1.53, 95% confidence interval [CI] 1.40–1.67, I2=74.7%; HR-based meta-analysis: HR=1.39, 95% CI 1.06–1.83, I2=77.5%). Results were similar when studies with <1 year (OR=1.50; 95% CI 1.36–1.67) or ≥1 year of follow-up (OR=1.54; 95% CI 1.30–1.84) were included in the risk meta-analysis. In the medication meta-analysis, the fixed-effects combination of the self-controlled medication studies showed that ADHD medication was protective against UPIs, and heterogeneity of studies was not significant (effect size 0.898, 95% CI 0.851–0.948, I2=32.8%). These results were robust to all sensitivity analyses, indicating that the type of OR (adjusted or unadjusted), the method used to diagnose ADHD, the definition of UPI, age, gender, comorbidities and the period when the study was conducted did not significantly affect the results.
These meta-analyses showed that children and adolescents with ADHD are at a higher risk of UPIs but that ADHD medication has a protective effect in preventing UPIs. However, this study had the following limitations: bias on individual studies; the low number of studies available for the meta-regression analyses; and the fact that it is unknown whether the protective effect of ADHD medication varies between medications, if it is influenced by other variables, or if non-pharmacological interventions also influence the risk of UPIs.
The authors concluded that these results have implications from both a research and clinical perspective. In terms of research, there is growing evidence that ADHD has an impact on quality of life, and the fact that ADHD is associated with increased risk of UPIs adds to this body of literature. From a clinical perspective, the authors recommend that parents of children and adolescents with ADHD should take extra preventative measures to minimise UPIs, and suggest that direct costs associated with hospital admissions may be reduced through use of ADHD medication. In addition, results from this study highlight that the practice of discontinuing ADHD medication during school holidays should be revised, as this period may be associated with an especially increased risk of UPIs.
Read more about the link between ADHD in children and adolescents and UPIs here
Ruiz-Goikoetxea M, Cortese S, Aznarez-Sanado M, et al. Risk of unintentional injuries in children and adolescents with ADHD and the impact of ADHD medications: A systematic review and meta-analysis. Neurosci Biobehav Rev 2018; 84: 63-71.