Detailed contribution information
| Contribution title | 2670 - Drug utilization and treatment patterns in children and adolescents with ADHD receiving guanfacine extended release or atomoxetine as second-line therapies |
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| Contribution code | PS02-64 (P) |
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| Form of presentation | Poster |
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| Abstract |
Objective To compare drug utilization and treatment patterns with guanfacine extended release (GXR) and atomoxetine (ATX) in children and adolescents with attention-deficit/hyperactivity disorder (ADHD) and previous stimulant treatment. Methods Medical claims data from 2010 to 2015 were extracted from the Truven MarketScan® database for patients aged 6–17 years with ≥1 claim for a stimulant for a primary diagnosis of ADHD in the 6 months before initiating GXR or ATX, and ≥1 claim for a first prescription of GXR or ATX in the 12-month follow-up (with the first 30 days of GXR or ATX as monotherapy). Cohorts were balanced using propensity score matching. Drug utilization (daily average consumption [DACON], adherence and persistence) and treatment patterns (maintenance, discontinuation, switching and augmentation) were assessed over the follow-up period. DACON was assessed over a 90-day period (starting 30 days after initiating GXR or ATX, to allow for potential dose titrations). Adherence was defined as a medication possession ratio (MPR) ≥0.8; persistence was defined as continuous, successive prescriptions without gaps >30 days. Clinical events (CEs) of interest (based on known safety profiles of GXR and ATX) were assessed to investigate a possible link between tolerability and adherence. Results After matching, each cohort included 954 patients. Mean (standard deviation [SD]) DACON was 1.26 (4.14) for GXR, and 1.06 (0.71) for ATX (p<0.01); mean (SD) MPR was 0.51 (0.34) for GXR, and 0.43 (0.32) for ATX (p<0.01). Rates of adherence and persistence were significantly greater with GXR (30.3% and 28.1%, respectively) than ATX (20.6% and 17.8%, respectively) (both p<0.01). Treatment patterns for GXR and ATX were significantly different (p<0.01), with lower rates of discontinuation (60.6% vs 69.4%) and switching (9.0% vs 11.3%), and higher rates of maintenance (24.1% vs 16.4%) and augmentation (6.4% vs 2.8%) for GXR than ATX. Kaplan–Meyer estimates for 1-year discontinuation rates were significantly lower for GXR than ATX (65.0% vs 76.3%; p<0.01). The proportion of patients with any CE of interest was 12.3% for GXR and 13.5% for ATX (p=0.58). Conclusions In children and adolescents with prior stimulant treatment, GXR was associated with a higher DACON, suggesting more frequent dose adjustments, than ATX. However, adherence and persistence were greater with GXR than ATX. Rates of CEs were similar between both cohorts. Study funded by Shire Human Genetic Therapies, INC. |