MEASURING AND PREDICTING THE FACTORS ASSOCIATED WITH PERSISTENCE TO ANTIDEPRESSANT THERAPY IN PATIENTS WITH DIABETES

Abstract

Objective: The objective of this study was to measure the rate of persistence to antidepressants and to identify the factors influencing persistence to these medications in patients with diabetes. Methods: We conducted a retrospective study among patients with diabetes enrolled in a commercial health plan between 2009 – 2012. The study population includes patients who were at least 18 years of age and diagnosed with major depression during this period. The patients were eligible for acute phase treatment and continuation phase treatment if they were enrolled at least 90 days and 180 days after the Index antidepressant Prescription Start Date (IPSD) respectively. The patients were eligible for the study if (1) there was no history of diagnosis of major depression for at least 120 days prior to the first episode of major depression (Index Episode Start Date-IESD) and (2) there was no history of an antidepressant dispensing for at least 90 days prior to the IPSD. Results: The mean age of the patients in both the phases was approximately 60 years. A majority were prescribed SSRI (Selective Serotonin Reuptake Inhibitors) antidepressants in acute (71.5%) and continuation (74.9%) treatment phases, 81.8% of the patients in acute phase and 72.8% in continuation phase had monotherapy, 210 patients in acute phase and 112 patients in continuation phase had no follow up visits. Only 60.1 % and 43.5% of patients were found to be persistent to acute and continuation treatment phases respectively. Acute Phase Treatment: The odds of non-persistence were higher for patients in age group 18-40 compared to patients aged 40 above (OR 0.46 P=0.0036). Across the class of antidepressants patients utilizing trazadone or mirtazapine (OR=2.35 P=0.02) were more likely to non-persist. Patients who had 1 to 3 (OR=0.19 P=0.0036). Across the class of antidepressants patients utilizing trazadone or mirtazapine (OR=2.35 P=0.02) were more likely to non-persist. Patients who had 1 to 3 (OR=0.19 P<0.0001) or more than 3 (OR=0.63 P<0.0001) follow up visits were found to have lower odds for non persistence compared to patients with no follow up visits during the treatment. Patients who had a combination treatment with either buproprion or tricyclic antidepressants (TCA) were found to be more likely to non-persist (OR=2.85 P=0.003). Continuation Phase Treatment: The odds of non-persistence were higher for patients in age group 18-40 compared to patients aged 40 above (OR 0.52 P=0.03). Patients who had 1 to 3 (OR 0.1 P Conclusion: In this