Incidence and costs of accidents among attention-deficit/hyperactivity disorder patients

The purpose is to analyze the incidence and costs of accidents among Attention-Deficit/Hyperactivity Disorder (ADHD) patients.

The analysis relied on administrative medical, pharmaceutical, and disability claims for a national manufacturer's employees, spouses, dependents, and retirees (n > 100,000). Accidental injuries were identified using ICD-9 codes for injuries or poisoning treatment. ADHD sample consists of individuals with at least one claim for ADHD during 1996-98 (NADHD = 1308), which was compared with a matched control sample. In addition to descriptive statistics, multivariate analysis involving logistic regression was used to model the probability of having an accident claim in 1998. This probability was estimated for the whole population, for adults alone, for children (under age 12 years), and for adolescents (age 12-18 years). We also estimated a generalized estimation equation (GEE) model to account for the possibility of multiple accident claims for a single patient.

ADHD patients had a greater probability of having at least one accident claim than their controls for children (28% vs. 18%), adolescents (32% vs. 23%), and adults (38% vs. 18%). Although ADHD patients' costs were greater than their controls for adults ($483 vs. $146), there was no difference for children or adolescents. However, among patients with accident claims, the average number of accident claims was similar for both groups (3.6 vs. 3.5) and costs were not statistically different. The multivariate analysis confirms this utilization pattern: the odds of having an accident for ADHD patients were 1.7 times greater than for controls.

ADHD was a significant predictor of having an accident claim. However, for people with an accident claim, ADHD patients and controls had a similar number of accident claims and costs.