Press Release Details

Average LDL Cholesterol Levels Decreased Approximately 10 Percent Among People Under Doctors' Care from 2001 to 2004


- Quest Diagnostics launches Health Trends(R), a national source of patient health information that provides insights from the nation's largest private database of clinical test results -

- Cholesterol levels decreased less in women than men -

LYNDHURST, N.J., Oct. 10 /PRNewswire-FirstCall/ -- Quest Diagnostics (NYSE: DGX), the nation's leading provider of diagnostic testing, information and services, announced today that it identified a significant and steady decline of approximately 10 percent over a four-year period in average LDL (low-density lipoprotein) cholesterol levels in blood tests ordered on behalf of patients under a physician's care in the United States. However, the decline was slower in women than in men.

The average serum LDL cholesterol level declined from 123.7 milligrams per deciliter (mg/dL) at the beginning of 2001 to 111.7 mg/dL at the end of 2004. The recommended upper limit of LDL cholesterol for people at average risk for heart disease is 130 mg/dL, according to the National Cholesterol Education Program (NCEP). Lowering LDL cholesterol, also known as "bad" cholesterol, decreases the risk of arteriosclerosis and heart attack.

The findings are contained in an LDL Cholesterol Heart Health Report released as the first in a series of Quest Diagnostics Health Trends, a new indicator of patient health based on de-identified patient testing data in the nation's largest private database of clinical test results. For the Heart Health Report, Quest Diagnostics conducted a retrospective analysis of data from nearly 80 million LDL cholesterol results reported by its laboratories across the U.S. from 2001 through 2004 for adult patients age 20 years and older.

The Heart Health Report is the first assessment of its kind to involve so many people, and it provides up-to-date information on national LDL cholesterol trends for people who visit the doctor. Other population-based cardiovascular disease studies rigorously evaluate general populations ranging from 3,000 to 60,000 well-characterized study participants and are often regional or localized in scope. Certain characteristics of the Quest Diagnostics data, such as seasonal variation and gender differences, have been well described in prior studies.

"The 10% decline we saw in average LDL cholesterol levels between 2001 and 2004 is a steeper decrease than has been reported in a published U.S. population study, and these data are very current," said Joyce G. Schwartz, M.D., Vice President and Chief Laboratory Officer for Quest Diagnostics. "In addition, women showed higher average LDL cholesterol levels than men, and their results declined less than the men's."

"The Quest Diagnostics study shows that cholesterol is decreasing in Americans who see their doctors and have their cholesterol measured, and this is very important for public health," said Frank M. Sacks, M.D., Professor of Cardiovascular Disease Prevention at Harvard School of Public Health. "I would expect that these patients have an improved quality of life because lower cholesterol means fewer heart attacks and other cardiovascular events."

The decline in average LDL cholesterol levels was observed across all age groups, but was most pronounced for tests performed on older patients. The decrease was greatest (approximately 13%) for people aged 70 years and older and least pronounced (approximately 7%) for the 20-to-39-year age range.

Gender Differences

The data also revealed gender differences in LDL cholesterol levels, which declined further in men than in women over the four-year period. The largest differences between men and women were observed in the older age groups. Overall, from January 2001 to December 2004, average LDL cholesterol in men fell from 124.0 mg/dL to 110.9 mg/dL. In women, average LDL cholesterol declined from 123.4 mg/dL to 112.5 mg/dL during the same time period. The rate of decline was larger in men than women, and is statistically significant.

"These data highlight a potentially important gender gap in cardiovascular disease risk among patients with access to medical care. The finding underscores the need to develop system approaches to improve the application of evidence-based guidelines and quality of care for both men and women," said Lori Mosca, M.D., M.P.H, Ph.D., Director, Preventive Cardiology, New York- Presbyterian Hospital and Associate Professor of Medicine at Columbia University.

"At a time when the world is looking to evidence-based medicine to drive better outcomes, we are proud to be able to utilize our unique clinical database to provide quantitative insights on the health of patients," said Surya N. Mohapatra, Ph.D., Chairman and Chief Executive Officer, Quest Diagnostics. "Our first Health Trends report provides a glimpse into how 'real-world medicine' is advancing the nation's heart health and well-being. This is an exciting undertaking and we are pleased to share our findings."

"The Quest Diagnostics' data are remarkably consistent with more conventional studies, such as the government's National Health and Nutrition Examination Survey (NHANES)," said Josef Coresh, M.D., Ph.D., Professor of Epidemiology, Biostatistics & Medicine at Johns Hopkins University. "The broad representation and large sample size of the Quest Diagnostics population make this report unique and gives Quest Diagnostics the ability to provide fresh data without the longer lag time necessarily associated with research studies, such as NHANES."

Quest Diagnostics is not providing interpretation of the data, which has to be considered in the context of the extensive published research in the field. Data used in the report only include test results with the patient's age, gender, and geographic region.

"The compilation of this large amount of lipid testing data represents an ambitious effort to assemble information that is potentially related to the health of Americans over the past few years of laboratory testing by Quest Diagnostics," said Peter W. F. Wilson, M.D., Professor of Medicine at Medical University of South Carolina and the former Director of Laboratories for the Framingham Heart Study. "However, there are limitations of the data that affect interpretation." The limitations include the fact that individuals or their physicians were not identified by name; some tests have been repeated for the same person; and the data does not include defining characteristics such as a person's ethnicity, medications, or medical history.

LDL cholesterol data was derived from results of 78.3 million tests ordered by physicians on their adult, predominantly non-hospitalized patients from January 1, 2001 through December 31, 2004. LDL cholesterol results were calculated from serum measurements of total cholesterol, HDL cholesterol and triglycerides using standardized laboratory procedures. The company plans to utilize its extensive database of de-identified laboratory test results to identify health trends for other medical conditions.

About Quest Diagnostics

Quest Diagnostics is the leading provider of diagnostic testing, information and services that patients and doctors need to make better healthcare decisions. The company offers the broadest access to diagnostic testing services through its national network of laboratories and patient service centers, and provides interpretive consultation through its extensive medical and scientific staff. Quest Diagnostics is a pioneer in developing innovative new diagnostic tests and advanced information technology solutions that help improve patient care. Additional company information is available at:

The statements in this press release which are not historical facts or information may be forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause actual results and outcomes to be materially different. Certain of these risks and uncertainties may include, but are not limited to, competitive environment, changes in government regulations, changing relationships with customers, payers, suppliers and strategic partners and other factors described in the Quest Diagnostics Incorporated 2004 Form 10-K and subsequent filings.

SOURCE Quest Diagnostics Incorporated

Gary Samuels - Media, +1-201-393-5700, or
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