Stimulant treatment patterns and compliance in children and adults with newly treated attention-deficit/hyperactivity disorder.

OBJECTIVE: To identify newly treated cases of attention-deficit/hyperactivity disorder (ADHD), assess the presence of comorbid psychiatric conditions, identify pharmacological treatment patterns, and examine treatment compliance rates among children and adults with newly diagnosed and pharmacologically treated ADHD in a managed care population.
METHODS: Children (aged 18 years or younger) and adults having newly treated ADHD were identified from medical and pharmacy claims in an administrative claims database from 6 health plans. Claims data for services or products provided between April 1, 1997, and September 30, 1999, was analyzed for the managed care population (604,538 children and 1,542,304 adults). Data on compliance, persistence, and pharmacological treatment patterns were collected for the 6 months prior to and the 18 months following each patient.s initial ADHD pharmacological treatment. A medication possession ratio (MPR) was calculated by dividing the number of days supplied in a prescription by the number of days until the next prescription was filled. Compliance was defined as an MPR >0.8 and persistence as an MPR >0.3.
RESULTS: The prevalence of diagnosed ADHD in this population was 0.7% (11,962 [2%] of children and 2,636 [0.2%] of adults) and incidence of ADHD was 0.04% (735 [0.1%] of children and 162 [0.01%] of adults). The most common comorbid psychiatric condition for incident cases was depression (31.6% of children and 63% of adults). Few children and adults switched their initial ADHD treatment agent, 11% and 12%, respectively. Dose titration occurred in 67% of children and 54% of adults. On average, changes in treatment (switching, titrating) took place after 2 to 3 months of treatment. Although patients, on average, obtained more than 6 refills for a total 200 days supply, the majority of patients (84% of children and 88% of adults) were compliant for less than 2 months over the period they were refilling prescriptions.
CONCLUSION: Although the majority of patients had dosage changes, these changes typically occurred after several months of treatment. Results suggest that, even though patients continued their ADHD medication for several months, they did not consistently take medication for more than 2 months. Given these treatment patterns, pharmacologic treatment in newly treated ADHD patients may be suboptimal and may impact outcomes, including the effectiveness and cost of treatment.