Adherence to Statin Therapy and LDL Cholesterol Goal Attainment by Patients With Diabetes and Dyslipidemia

Abstract

OBJECTIVE—The purpose of this study was to assess the relationship between adherence to statin therapy and LDL cholesterol goal achievement in patients with diabetes and dyslipidemia. RESEARCH DESIGN AND METHODS—The records of patients being medically treated for dyslipidemia in a managed care diabetes program from January 2001 to December 2002 were used to assess LDL cholesterol goal attainment (<100 mg/dl) and to compute a 9-month medication possession ratio (percentage of days when medication was available [MPR], beginning with the first prescription in the database). RESULTS—A total of 653 patient records was analyzed. The average MPR was significantly higher for men than for women (0.75 vs. 0.66, P < 0.05). Overall, 44% (n = 290) of the patients achieved an LDL cholesterol level <100 mg/dl (52% of men and 37% of women, P < 0.05). A significant correlation emerged between MPR and plasma LDL cholesterol (P < 0.001), and MPR was significantly higher in patients who achieved the LDL cholesterol target than in those who did not (0.82 vs. 0.61, P < 0.05). CONCLUSIONS— Although statins are highly effective for decreasing LDL cholesterol levels in patients with dyslipidemia, including those with diabetes, failure to reach LDL cholesterol targets remains common. Adherence to statin therapy, as reflected by MPR, is closely related to LDL cholesterol goal attainment in patients with diabetes and dyslipidemia. The probability of goal achievement appears to increase substantially when the MPR is >0.80. Pharmacy records can be used to identify patients who are poorly compliant with statin therapy and at high risk for failure to attain LDL cholesterol goals. Because outcomes are directly related to patients’ medication-taking behavior, when clinical goals (such as serum cholesterol levels) are not being reached, adherence should be the first item assessed by the clinician.