Differences in compliance patterns across the selective serotonin reuptake inhibitors (SSRIs)

Abstract

ABSTRACTObjective: To evaluate differential compliance rates between immediate-release (IR) selective serotonin reuptake inhibitors (SSRI) and a controlled-release (CR) SSRI in patients initiating SSRI therapy.Methods: A retrospective analysis of patients initiating treatment with SSRIs identified in the IHCIS National Managed Care Database between July 2001 and December 2002 was conducted. Logistic regression models were used to assess differences in 6‐month compliance rates, controlling for age, gender, utilization of mental health specialty care services, titration rates, diagnoses, and comorbidities. Compliance was defined as having a minimum medication possession ratio of 80% over a 180-day period without evidence of a 15‐day gap prior to 90 days of therapy.Results: There were 116 090 patients included in the study, with approximately 4% receiving a CR SSRI and 96% receiving IR SSRIs. Approximately 25% of patients had a diagnosis for depression, 16% had a diagnosis for anxiety, and 13% had a diagnosis for both anxiety and depression. Overall, 54.2% were noncompliant with therapy, while 30.2% of patients were compliant with therapy, and 15.7% had evidence of a therapy change. After controlling for baseline covariates, patients initiating IR SSRIs were 14% less likely to be compliant compared to those initiating paroxetine CR ( p < 0.0001). Patients initiating on paroxetine IR were least likely to be compliant (odds ratio [OR] 0.788; p < 0.0001), followed by escitalopram (OR 0.850; p = 0.0179), sertraline (OR 0.877; p = 0.0005), citalopram (0.909; p = 0.0114), and fluoxetine (OR 0.916; p = 0.0250).Conclusions: Approximately 54% of patients initiating SSRI therapy were noncompliant with SSRI therapy over a 6‐month period, with the lowest level of compliance found in patients receiving IR SSRI agents. Future studies should assess the effect of compliance on economic measures and determine if reductions in resource utilization are found across specific SSRI agents.