P. Michael Ho, MD, PhD1,2 ? John S. Rumsfeld, MD, PhD1,2 ? Frederick A. Masoudi, MD, MSPH2,3,4 ? David L. McClure, PhD, MSc5 ? Mary E. Plomondon, PhD, MSPH1 ? John F. Steiner, MD2,4 ? David J. Magid,

We evaluated the association between medication nonadherence and outcomes among subjects with diabetes mellitus. Nonadherent subjects had higher blood pressure, glycosylated hemoglobin, and low-density lipoprotein cholesterol levels. In addition, there was an association between medication nonadherence and an increased risk of all-cause hospitalization and all-cause mortality. These findings suggest that interventions are needed to increase medication adherence so that patients can realize the full benefit of prescribed therapies.