Early discontinuation and suboptimal dosing of duloxetine treatment in patients with major depressive disorder: analysis from a US third-party payer perspective.

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.