Combination therapy patterns and predictors of ADHD in commercially insured and Medicaid populations.

OBJECTIVES: Several stimulant and nonstimulant medications are used alone or in combination to treat attention-deficit/hyperactivity disorder (ADHD). Little is known about the current prevalence and predictors of combination therapy. This analysis describes ADHD medication use focusing on combination versus monotherapy. METHODS: Health insurance claims from the Truven Health MarketScan® Commercial Database and Multi-State Medicaid Database were analyzed for patients with an ADHD diagnosis (International Classification of Diseases, Ninth Revision codes 314.0x). Patients included were aged ≥ 6 years as of January 2010, continuously enrolled from July 2009 through December 2010, and had a claim for an ADHD medication in 2010. Medication use was measured in treatment months during 2010. Baseline demographic and clinical predictors of combination therapy (> 1 ADHD medication class in the same month) involving atomoxetine, long-acting stimulants, and α2-adrenergic agonists were explored using logistic regression, with generalized estimating equations to account for within-patient correlation between months. RESULTS: Commercially insured patients with ADHD (N = 211 226) were primarily aged 6 to 17 years (58.4%) and male (61.5%). Attention-deficit/hyperactivity disorder with hyperactivity was present in 15.8% of these patients. Combination therapy was used in 10.3% of 1 125 119 treatment months. Short-acting stimulants and α2-adrenergic agonists had the highest combination use (45.3% and 54.0%, respectively). Patients with ADHD insured through Medicaid (N = 125 104) were primarily aged 6 to 17 years (94.4%) and male (69.5%). Hyperactivity was present in 39.7% of these patients. Combination therapy was used in 24.0% of 721 986 treatment months. Short-acting stimulants, α2-adrenergic agonists, and intermediate-acting stimulants had the highest combination use (70.0%, 63.8%, and 51.8%, respectively). In multivariate models for both data sources, female patients were less likely to use combination therapy. Patients with hyperactivity were more likely to use combination therapy. Tics/Tourette's syndrome was associated with combination therapy for atomoxetine and long-acting stimulants. CONCLUSION: In commercially insured and Medicaid ADHD populations, combination therapy rates differed by medication class, as did the demographic and clinical characteristics statistically significantly associated with combination therapy. This suggests that these medications may be used differently in clinical practice.

Predictors of pain medication selection among patients diagnosed with fibromyalgia.

OBJECTIVES: Several pharmacologic therapies have been recommended for managing fibromyalgia. However, the factors associated with each treatment initiation have not been well established. This study assessed factors that were associated with the use of duloxetine vs. other pain medications among patients with fibromyalgia. RESEARCH DESIGN AND METHODS: Administrative claims from a large, U.S. commercially insured population were analyzed using a retrospective cohort design. Patients with fibromyalgia who were 18 to 64 years old and initiated duloxetine vs. selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs), venlafaxine, gabapentin, pregabalin, tramadol, or nontramadol opioids between January 1, 2007 and December 12, 2008 were selected. Treatment initiation was defined as no access to the same medication over the previous 90 days, with the most recent initiation date as the index date. All patients selected had at least one fibromyalgia diagnosis (ICD-9-CM: 729.1) in the 12 months prior to initiation of each study medication. Multiple logistic regression models were estimated to assess the predictors of initiating duloxetine vs. each of the other medications. RESULTS: The study included 117,305 patients with fibromyalgia (48 years of age on average; 76% women) who initiated duloxetine (n = 5,827), SSRIs (n = 8,620), TCAs (n = 5,424), venlafaxine (n = 2,038), gabapentin (n = 5,733), pregabalin (n = 11,152), tramadol (n = 7,312), or nontramadol opioids (n = 71,199). Common fibromyalgia-related comorbidities were low back pain (31% to 49%), osteoarthritis (14% to 21%), and sleep disturbance (10% to 15%). Controlling for demographic and clinical characteristics, patients who received pregabalin in the prior 12-month period were more likely to initiate duloxetine. Patients from other treatment cohorts, except for those in the pregabalin and nontramadol opioid cohorts, were more likely to re-initiate the same prior medication than to begin treatment with duloxetine. Other predictors of duloxetine initiation included history of rheumatoid and sleep disturbance. CONCLUSIONS: The presence of select comorbidities and prior use of certain medications were associated with the duloxetine initiation among working-age, commercially insured patients with fibromyalgia.