Impact of cost-sharing on treatment augmentation in patients with depression.

OBJECTIVES

Many patients with depression do not respond to first-line antidepressant therapy and may require augmentation with another concurrent treatment such as a second antidepressant, a stimulant, a mood stabilizer, or a second-generation antipsychotic (SGA). The objective of this study was to examine the relationship between patient cost-sharing and the use of augmentation among a sample of commercially insured patients.

STUDY DESIGN

Retrospective observational study of adult patients diagnosed with depression and receiving antidepressant therapy (n = 48,807).

METHODS

Logistic regression models estimated the likelihood of augmentation as a function of patient cost-sharing amounts. An alternative-specific conditional logit model of the likelihood of each augmentation class, varying the cost-sharing prices faced for each class, was also estimated. All models controlled for sociodemographic characteristics, physical and mental comorbidities, health plan type, and year of index antidepressant therapy initiation.

RESULTS

The range of mean copayments paid by patients for augmentation therapy was from $27.05 (antidepressant) to $38.81 (SGA). A $10- higher cost-sharing index for all augmentation classes was associated with lower odds of augmentation (adjusted odds ratio = 0.85; 95% confidence interval 0.79-0.91). Doubling the costsharing amount for each augmentation class was associated with a smaller percentage of patients utilizing each class of augmentation therapy.

CONCLUSIONS

Employers and payers should consider the relationship between cost-sharing and medication utilization patterns of patients with depression.