Objective: Little is known about early discontinuation of duloxetine therapy or the effect that initial dose has on discontinuation in patients with major depressive disorder (MDD).
Methods: Data from a private payer insurance claim database included 6132 patients with MDD who started duloxetine between 7/1/2005 and 6/30/2006, had no prescription for duloxetine in the previous 3 months, and were enrolled for 12 months before and after initiation. Chi-square tests, t-tests, and logistic regression were used to compare demographic, clinical, and healthcare cost data stratified by length of continuation. Early discontinuation was defined as continuation ≤30 days. Healthcare costs, persistence, and adherence were compared between patients with suboptimal initial dose (<40 mg/day) and those with recommended initial dose (40-60 mg/day).
Results: Discontinuation rates were 16.8% at ≤30 days, 16.7% at 31-90 days, 14.9% at 91-180 days, and 51.6% at >180 days. Suboptimal initial dose, younger age, male gender, prior benzodiazepine use, insomnia, psychiatric disorders, infectious diseases, digestive disorders, genitourinary disorders, and injury/poisoning increased the likelihood of early discontinuation (Odds ratios [ORs]: 1.18-2.16), while recent use of SSRIs or venlafaxine XR decreased the likelihood (ORs: 0.67-0.68). Compared with patients who persisted with therapy for >180 days, patients who discontinued early had more hospital admissions, longer hospital stays, and more ER visits during the 1-year follow-up (all p-values <0.01). Patients with an initial dose <40 mg/day had shorter persistence (p < 0.001) and lower rates of adherence (p < 0.001) compared with patients with an initial dose of 40-60 mg/day.
Limitations: Limitations of this study were those of all analyses based on data from insurance claim databases.
Conclusions: Early discontinuation was associated with increased healthcare utilization. Demographic and clinical predictors of early discontinuation were identified that may help target care for at-risk patients. Beginning therapy within the recommended dose range may improve persistence.