Screening for Lipid Disorders

Implementation of the U.S. Preventive Services Task Force (USPSTF) Recommendations

By Nirmala Trisna Anak Agung Istri
(for PH7530 course - Spring 2005, Dr. Paul G. Farnham, Institute of Public Health, Georgia State University)

High blood cholesterol is a significant modifiable risk factor for heart disease, the major cause of death in the United States. Cholesterol is a fat-like substance (lipid) that is present in cell membranes, contains both lipid and proteins (lipoproteins), which has three major classes of lipoproteins, i.e. low density lipoproteins (LDL), high density lipoproteins (HDL), and very low density lipoproteins (VLDL).[1] Approximately 30%-40% of coronary heart disease (CHD) and 10%-20% of strokes in the United States are attributable to elevated cholesterol level.[2] This paper presents recommendations from the U.S. Preventive Services Task Force (USPSTF) to screen for any lipid disorders in order to reduce the prevalence of cardiovascular disease and how the implementations are viewed by other health professionals and general public.

The U.S. Preventive Services Task Force (USPSTF) released guidelines of screening for lipid disorders in adults in 2001. It provides strong recommendation that “clinicians routinely screen men aged 35 years and older, and women aged 45 years and older for lipid disorders and treat abnormal lipids in people who are at increased risk of CHD”. Screening is recommended for younger men (20-35 years of age) and women (20-45 years of age) if the person has diabetes, family history of cardiovascular disease, family history suggestive of familial hyperlipidemia, or multiple CHD risk factors. There is no certain age when the screening should be stopped.[3] Screening for lipid disorders or high blood cholesterol and other lipid abnormalities is “designed to reduce the average blood cholesterol level in the general population” and “to identify individuals who have elevated blood cholesterol or related disorders and who are candidates for cholesterol management in the clinical setting”.[4]

The USPSTF recommendations are supported by two other guidelines, which are:

§ The National Cholesterol Education Program (NCEP) Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel – ATP) provides recommendations for clinical management of high blood cholesterol. There have been three ATP reports with supporting recommendations, which are as follows:

a. ATP I provided “a strategy for primary prevention of coronary heart disease (CHD) in persons with high levels of low density lipoprotein (LDL) cholesterol (≥160mg/dL) or those with borderline-high LDL cholesterol (130-159mg/dL) and multiple risk factors”

b. ATP II added the recommendation for “intensive management of LDL cholesterol in persons with established CHD”, and set a new lower LDL cholesterol goal of ≤100mg/dL for CHD patients

c. ATP III recommends “more intensive LDL-lowering therapy in certain groups of people”.

NCEP recommendations mainly put focus on LDL level in the lipid disorders screening. There has been strong evidence showing significant association between increasing level of LDL and higher risk of having CHD.[5]

§ Institute for Clinical Systems Improvement (ICSI) came up with complementary clinical recommendations on lipid screening in adults, children, and adolescents.

a. For adults, ICSI recommends screening for men over age 34 and women over age 44 every five years, with nutrition and exercise assessment.

b. For children over the age of 2 and adolescent, ICSI recommends increasing appropriate lipid disorders screening for those at risk for familial hypercholesterolemia, by assessing nutrition and exercise status also by reviewing lipid status of first-degree relatives. Children or adolescent should have individual case management if LDL-cholesterol is ≥164mg/dL.[6]

For population at risk of or having CHD, lipid disorders screening recommendations are not adequately applied. A retrospective study on adult outpatients from nationwide medical practices in the period of 1994-1996 found that only 44% of patients with coronary artery disease had annual diagnostic testing of LDL cholesterol.[7] A study on stroke patients in a large rehabilitation unit in 1999-2000 found that only 25% of people undergoing rehabilitation at that institution after an acute stroke underwent lipid screening within 48 hours of admission.[8] In the Veterans Affairs (VA) health system, lipid disorder screening rates were low as found in 1999-2001, where 30% of CHD patients not receiving any form of cholesterol screenings.[9] Physicians only followed the guidelines to obtain an LDL value, but only 50% of those who need further treatment actually receive any lipid-lowering intervention and treatment.[10]

There are limited current data on the evaluation of lipid disorders screening guidelines. Yet, surveys found that the guidelines have started to be implemented in the general population. Statistics showed that the number of people who have had the screening increased significantly. In the period of 1991-1999, prevalence of screened adults in the United States increased 2.9% points (screening prevalence in 1991: 25.7%, 1999: 28.6%).[11] During 1999-2002, 63% of adult populations have had their cholesterol checked where women, older persons, and Whites race group are more likely to undergo the screening.[12] These numbers could be improved if the guidelines are more widely publicized. A poll in 2003 found that there is a public confusion on who should undergo cholesterol screening and how young should a person get the cholesterol checked.[13]

The importance of cholesterol screening as recommended by USPSTF, NCEP, and ICSI is supported by major stakeholders in the U.S. health care system. Two national health objectives for 2010 are reducing the proportion of adults with high total blood cholesterol levels to 17% and increasing the proportion of adults who have had their blood cholesterol checked within the preceding five years to 80% (objectives 12-14 and 12-15).[14] Access to lipid disorders screening for the elderly population in the U.S. has been broaden by the implementation of the Medicare Cholesterol Screening Coverage Act of 2003. As of January 1, 2005, Medicare part B beneficiaries are covered to have preventive screenings for cholesterol and other lipid levels every five years, with no deductible nor co-payments.[15]^,[16] To increase public awareness on the importance of lowering cholesterol levels, the National Heart, Lung, and Blood Institute (NHLBI) set the month of September as National Cholesterol Education Month. On this month, everyone is encouraged to actively promote healthy lifestyle and undergo cholesterol screening as recommended by NCEP – ATP III guidelines.[17]

Compliance to the USPSTF guidelines for lipid disorders screening should be enforced so that people at risk or those with CHD adequately receive screening and treatment for any lipid disorders. Public education on USPSTF guidelines and other supportive recommendations should be informed to the public to reduce any recommendation confusions and should emphasize the awareness campaign to those who are less likely to have cholesterol screening.

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References:

[1] National Cholesterol Education Program (NCEP). Third Report of the NCEP Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) – Final Report. National Institute of Health. NIH May 2001; Pub. No. 01-3670.

[2] Centers for Disease Control and Prevention (CDC). National Cholesterol Education Month – September 2001. Morbidity and Mortality Weekly Report (MMWR) September 7, 2001;50:753.

[3]U.S. Preventive Services Task Force (USPSTF). Screening for Lipid Disorders – Recommendations and Rationale. Agency for Healthcare Research and Quality. AHRQ April 2001; Pub. No. 02-503A: 47-52.

[4] National Heart, Lung, and Blood Institute (NHLBI). Recommendations Regarding Public Screening for Measuring Blood Cholesterol – Summary/Recommendations. National Institute of Health. NIH September 1995; Pub. No. 95-3045.

[5] National Cholesterol Education Program (NCEP). Third Report of the NCEP Expert Panel on Detection, Evaluation, and Treatment of High Blood Cholesterol in Adults (Adult Treatment Panel III) – Executive Summary. National Institute of Health. NIH May 2001; Pub. No. 01-3670.

[6] Institute for Clinical Systems Improvement (ICSI). Lipid screening in adults. Bloomington (MN): Institute for Clinical Systems Improvement (ICSI); 2004 Jun.

[7] Sueta, Carla et al. Analysis of the Degree of Undertreatmnet of Hyperlipidemia and Congestive Heart Failure Secondary to Coronary Artery Disease. Am J Cardiol 1999;83:1303-1307.

[8] Bogar, Mark D., Jeffrey R. Basford, Randal J. Thomas. Rate and Adequacy of Cholesterol Screening in Patients Admitted to a Large Rehabilitation Unit After Stroke. Arch Phys Med Rehab January 2005;86:69-72.

[9] Woodard, LeChauncy D., Kressin, Nancy R., Petersen, Laura A.Is Lipid-Lowering Therapy Underused by African Americans at High Risk of Coronary Heart Disease Within the VA Health Care System?Am J Public Health 2004;94:2112-2117.

[10] Frolkis, Joseph P. et al. Physician Noncompliance with the 1993 National Cholesterol Education Program (NCEP-ATPII) Guidelines. Circulation 1998;98:851-855.

[11] Centers for Disease Control and Prevention (CDC). National Cholesterol Education Month – September 2001. Morbidity and Mortality Weekly Report (MMWR) September 7, 2001;50:755.

[12] Centers for Disease Control and Prevention (CDC). National Cholesterol Education Month – September 2001. Morbidity and Mortality Weekly Report (MMWR) February 11, 2005;54:117-119.

[13] Mundell E.J. Public Confused on Cholesterol, Cancer Screening. MedicineNet.com. Available at http://www.medicinenet.com/script/main/art.asp?articlekey=31683. Accessed March 30, 2005.

[14] Healthy People 2010. Understanding and Improving Health. Available at http://www.healthypeople.gov/document/html/objectives/12-15.htm. Accessed March 30, 2005

[15] Medicare. The Official U.S. Government Site for People with Medicare. Available at http://www.medicare.gov/Health/cardio.asp. Accessed March 30, 2005

[16] American Heart Association (AHA). AHA applauds introduction of legislation guaranteeing Medicare coverage of cholesterol and lipid screening. Available at http://www.americanheart.org/presenter.jhtml?identifier=3009071. Accessed March 30, 2005

[17] National Heart, Lung, and Blood Institute (NHLBI). September is National Cholesterol Education Month. Available at http://hin.nhlbi.nih.gov/cholmonth/. Accessed March 30, 2005