Nonadherence to depression treatment guidelines among veterans with diabetes mellitus

Objective: To assess the adequacy of antidepressant dosage and duration among veterans with and without diabetes mellitus (DM), as well as provider-level and patient-level predictors of depression care quality, based on Veterans Health Administration (VHA) evidence-based clinical practice guidelines. Study Design: Retrospective (1997-2005) cohort study of administrative, clinical, and pharmacy data from a midwestern VHA facility. Methods: The sample included 2332 subjects (773 with DM) who had a new episode of depression, received antidepressant therapy, and had neither schizophrenia nor bipolar disorder. Antidepressant dosage and duration were evaluated in the acute and continuation phases. Dosage was adequate if the treatment dosage met the minimum therapeutic dosage specified in VHA guidelines. Treatment duration was adequate if the medication possession ratio was at least 80%. Multivariate logistic regression analysis was used to calculate odds ratios (ORs), adjusted for demographic, clinical, and healthcare utilization characteristics. Results: Most subjects received an adequate dosage during the acute (88%) and continuation (58%) phases. Subjects with DM were 1.51-fold more likely to receive adequate dosage during the acute phase but were similarly likely (OR, 1.15) to receive adequate dosage during the continuation phase. Few subjects (<10%) received adequate treatment duration. Diabetes mellitus was not associated with less adequate duration during the acute phase (OR, 1.14). Few factors were identified as significant predictors of both antidepressant dosage and duration. Conclusions: Diabetes mellitus did not adversely affect depression care quality. Adequate antidepressant dosages were prescribed, but treatment duration fell short of guideline recommendations. Strategies to more effectively manage depression treatment are needed.