Results of retrospective chart review to determine improvement in lipid goal attainment in patients treated by high-volume prescribers of lipid-modifying drugs

Abstract

Background: There is a primary focus in cholesterol management on the elevated low-density lipoprotein cholesterol (LDL-C) component of dyslipidemia and a secondary focus on the other components of dyslipidemia, such as low high-density lipoprotein cholesterol (HDL-C), high triglycerides (TGs), and high non-HDL-C.

Objective: This was a physician practice analysis to examine the real-world therapeutic management of patients diagnosed with hyperlipidemia and/or hypercholesterolemia according to the guidelines of the National Cholesterol Education Program (NCEP) Adult Treatment Panel Third Report (ATP III) and the American Heart Association (AHA). Additionally, the number of patients who should be diagnosed with mixed hyperlipidemia instead of hyperlipidemia or hypercholesterolemia was estimated.

Methods: A total of 600 high-volume prescribers of lipid-modifying drugs were identified in 6 metropolitan areas using the IMS Health prescription database. A total of 101 physician prescribers (about 17%) agreed to participate in the study and had the necessary medical records available. The participating prescribers were asked to identify all patients aged between 18 and 79 years who were seen in their practice in the last 2 years having a diagnosis of hyperlipidemia (International Classification of Diseases, Ninth Revision, Clinical Modification [ICD-9-CM] code 272.4) and/or hypercholesterolemia (ICD-9-CM code 272.0). ICD-9-CM code 272.2 (mixed hyperlipidemia) was purposely excluded from the criteria for patient chart selection in order to estimate the prevalence of mixed hyperlipidemia in patients previously diagnosed with hyperlipidemia and/or hypercholesterolemia. A random number generator was used to select 25 patient medical records from each office. A common instrument was used to collect data on patient demographics; clinical history; comorbid disease states; laboratory test results, including liver function; and 4 values for serum cholesterol (total cholesterol, LDL-C, HDL-C, TG). Total cholesterol was recorded to permit calculation of non-HDL-C. Data collection via patient chart abstraction occurred from March 2004 through August 2004, performed by a staff member in each physician practice who had been trained for this purpose. Drug prescribing was identified from the patient chart.

Results: For the physician practice assessment portion of the project, we used patient charts if there was a complete (total cholesterol, TG, HDL-C, and LDL-C) lipid profile for baseline and follow-up, and a minimum of 6 weeks between baseline and follow-up values. At follow-up, the proportion of patients meeting goal lipid values according to the guidelines for LDL-C was 68%, 63% for HDL-C, 59% for TG, and 68% for non-HDL-C. Only 32% of patients met all 3 goals (LDL-C, HDL-C, and TG). The average time between the baseline and follow-up lipid profile was 3.7 years, with a median of 2.9 years, and a minimum of 6 weeks and a maximum of 42 years. Compared with baseline, the most recent follow-up lipid assessment for HDL-C goal attainment showed improvement by an absolute 6%, from 57% to 63% of patients. TG goal attainment improved an absolute 18% (from 41% to 59%), LDL-C goal attainment improved an absolute 45% (from 23% to 68%), non-HDL-C goal attainment improved an absolute 46% (from 22% to 68%), and the combined goals of LDL-C, HDL-C, and TG improved from 8% of patients at baseline to 32% at follow-up. Of the 2,119 patients in the study population, 1,784 (84%) at the time of chart review had been prescribed at least 1 lipid-modifying medication: 1,552 (87%) a single lipid-modifying medication and 232 (13%) combination therapy. The hydroxymethylglutaryl (HMG) coenzyme-A reductase class (statins) accounted for 89% of the monotherapy regimens. Of the patients with baseline LDL-C, HDL-C, and TG readings, 40% could have been diagnosed as having mixed hyperlipidemia, defined as having (a) baseline LDL-C greater than their NCEP ATP III goal and (b) either baseline TG of >150 mg/dL or a baseline HDL-C of <40 mg/dL for males or <50 mg/dL for females. Of the 40% of patients estimated to have mixed hyperlipidemia, 69% were prescribed lipid-modifying monotherapy, 18% were prescribed combination drug therapy, and 14% were not prescribed drug therapy.

Conclusion: Attainment of therapeutic goals for serum lipids improved from baseline to follow-up, but approximately one third of patients did not achieve individual lipid goals and two thirds of patients did not attain goal for all 3 targets (LDL-C, HDL-C, and TG).