This suggests that the protective effect of improved medication adherence among these longer-standing diabetes patients is negated by other factors that contribute to poor glycemic control. The phenomenon of poor glucose control in patients with disease of long duration has been attributed to islet cell exhaustion, i.e. decreasing pancreatic function, and subsequent lower levels of secreted insulin. This, in combination with insulin resistance, which is characteristic in type 2 diabetes, yields the worsening of glucose control over time. As many diabetes patients are taking multiple chronic medications, which are actively managed by physicians, some of these medications will only be GF 109203X prescribed for intermittent periods. Consequently, when examining adherence to multiple medications, the ability to relate prescriptions filled to prescriptions written, as done in this study, may likely be critically important. Additionally, the variation among studies in measurements of medication adherence may substantially influence the strength of its association with glucose control. Many studies have used subjective patient-reported assessments of adherence rather than quantitative measures, such as medication possession ratios. Although self-reported medication adherence is a widely accepted measure in research, there are well-documented biases and errors in member-reported adherence measures. The novel measure we utilized to evaluate weighted adherence to multiple medications was capped by first and last prescriptions dispensed, and detects those patients who were written a prescription but did not fill it. This potentially provides a more accurate indication of the complete medication period intended by the physician. Previous studies which have objectively measured adherence for multiple medications, such as Choudry et al.��s, do not utilize written prescription data, and therefore may overestimate poor adherence because of the inability to capture physician intended treatment gaps. Therefore, the MWA measure in our study potentially captures these varying treatment regimens and the Dronedarone hydrochloride active medication management of physicians more accurately than traditional MPR measures.