Large Disparities in Kidney Testing Based on Disease, Gender and State, Quest Diagnostics Health Trends(TM) Report Finds

MADISON, N.J. (Map) - MADISON, N.J., March 12 /PRNewswire-FirstCall/ -- Diabetes and hypertension are the two leading risk factors for chronic kidney disease (CKD), responsible for up to two-thirds of cases. Yet a new study that will be presented at a National Kidney Foundation Spring Clinical Meeting next month indicates there is wide discrepancy in diagnostic testing for kidney disease among patients with these conditions, with patients with high blood pressure (hypertension) tested at half the rate as those with diabetes. The Quest Diagnostics Health Trends(TM) Report, "Chronic Kidney Disease - An Analysis of Testing Rates by Co-Morbidity, State and Gender in the U.S.," which is based on tests ordered for more than 5 million patients, also highlights large discrepancies in diagnostic testing by state and gender, with a distinct bias in diagnostic testing favoring men in every age range.

The latest Quest Diagnostics Health Trends Report provides new insights into testing trends for CKD in at-risk diabetes and hypertension patients, expanding on information provided by the company's earlier Health Trends Report on Chronic Kidney Disease. The first report, which was presented in November 2007, examined testing rates for patients with diabetes and/or cardiovascular disease and CKD in the U.S., and found that a majority of these patients are not being tested for CKD according to medical guidelines. Diagnostic testing in patients with one or more of these high-risk conditions is essential to identify CKD and to slow or halt disease progression. More than 25 million American adults have CKD, and deaths from untreated CKD have increased 52 percent over the last 16 years.

The March 2008 Quest Diagnostics Health Trends(TM) Report announced today reviewed the use of microalbumin testing, a widely available urine test of kidney damage and a key indicator of CKD. The National Kidney Foundation (NKF) recommends that adults with diabetes and/or hypertension receive an annual test for microalbuminuria, a condition characterized by the excretion of albumin in urine. The report shows that while microalbumin testing for CKD in patients with diabetes and/or hypertension was low overall (32.7 percent), rates for those with hypertension were significantly lower (22.3 percent) than in patients with diabetes (43.1 percent). These findings, based on diagnostic tests performed for more than 5 million patients in the Quest Diagnostics database, were released by Quest Diagnostics Incorporated (NYSE: DGX) to coincide with World Kidney Day on March 13. Results of this analysis will be presented at the National Kidney Foundation 2008 Spring Clinical Meeting, April 2-6, 2008, in Dallas, Texas.

"More aggressive monitoring in the early stages of kidney disease allows more time for evaluation and intervention. We need to work together to promote implementation of early detection and treatment of chronic kidney disease," said Joseph A. Vassalotti, M.D., chief medical officer, National Kidney Foundation. "The burden of type 2 diabetes and hypertension is expected to grow as the Baby Boomers age and as the obesity epidemic continues. The increase in diabetes and hypertension, the major risk factors for chronic kidney disease, will also drive up the rates of chronic kidney disease unless there are major improvements in diabetes and hypertension management."

The Quest Diagnostics report is based on findings from 6.2 million eGFR (estimated Glomerular Filtration Rate) calculations and microalbumin test results, two key indicators physicians use to diagnose and stage CKD, performed by Quest Diagnostics between November 2005 and October 2006 on 5.2 million patients who saw a healthcare professional. Among patients who had an eGFR test result, approximately 19 percent had a result below 60 mL/min/1.73 m, a level indicative of impaired kidney function. The analysis determined the percentage of patients with eGFR values below 60 in tests conducted in November 2006 who also had a microalbumin test performed during the previous 12 months. The reported difference in testing rate between the diabetes and hypertension groups was statistically significant (p<0.001).

Diabetes affects 7 percent of the U.S. population and more than 21 percent of adults over age 60, while hypertension affects approximately 30 percent of American adults and more than half of those over age 60.

States Vary Widely in Compliance with CKD Testing Guidelines

The analysis also showed wide variability in microalbumin testing rates for patients with diabetes or hypertension by state. Testing in patients with diabetes ranged from a low of 13.0 percent in Iowa to a high of 61.4 percent in Massachusetts. For patients with hypertension, the percentage of tests ranged from a low of 0.5 percent in Iowa to a high of 26.3 percent in Utah. Patients with hypertension were tested less frequently than patients with diabetes -- at a rate of almost two to one -- in virtually every state assessed for the study.

"It is a concern that patients in some states are not getting appropriate care to manage this potentially life-threatening disease," said Joyce G. Schwartz, M.D., vice president and chief laboratory officer, Quest Diagnostics. "Even in those states that had higher testing rates, the percentage of patients receiving the microalbumin test overall is far lower than recommended."

Bias Against Women Found

The Quest Diagnostics Health Trends(TM) Report also found that even though more women were identified as having an early stage of CKD based on their eGFR value, they were less likely to receive a microalbumin test (31.1 percent for women compared with 34.3 percent of men). This bias toward ordering more testing on men was similar whether patients had diabetes or hypertension. Among patients with diabetes, 42.1 percent of women were tested for microalbumin, compared to 44.1 percent of men. Similarly, 20.2 percent of women and 24.4 percent of men with hypertension received the test. The largest differences in testing rates were seen in patients between 31 and 40 years of age (42.9 percent for women versus 47.8 percent in men for patients with diabetes, and 18.7 percent for women versus 24.7 percent in men for patients with hypertension). The overall difference for men and women was statistically significant (p<0.001) as were the differences between men and women for each age group and disease group (at least at the p<0.05 level). The exceptions were for men and women in the 18-30 age group (for the diabetes and hypertension group, p-values were 0.32 and 0.12, respectively) and the 41-50 age group for diabetes (p-value of 0.63).

"Based on the Quest Diagnostics data, it is evident that physicians are not applying the guidelines equally for women and men, and most likely endangering the lives of women in particular," said Massy Safai, M.D., former faculty at University of California San Francisco, Division of Nephrology, and former director of the Low GFR Clinic at San Francisco General Hospital. "This finding is particularly disturbing in light of a number of studies that demonstrate a higher prevalence of CKD in advanced stages (3-5) in women compared to men. An aging population and the epidemic of patients with type-2 diabetes is causing a surge in the number of patients with CKD in the U.S. A yearly microalbuminuria test is essential to detect CKD and initiate appropriate treatments in at-risk patients of both genders."

About Chronic Kidney Disease

Chronic kidney disease (CKD) includes conditions that damage the kidneys and decrease their ability to effectively remove wastes from the body through urine. More than 25 million American adults have CKD. If kidney disease worsens, wastes can build to high levels in the blood, potentially leading to complications such as hypertension, anemia (low blood count) and kidney failure. Kidney disease also increases the risk of heart and blood vessel diseases. Clinical evidence has shown that early detection and treatment of CKD could slow or prevent the progression of the disease to chronic kidney failure, as well as reduce the risk of heart attack, stroke and death. Deaths from CKD have increased 52 percent over the last 16 years.

About CKD Testing

Two of the most widely used tests for CKD are the microalbumin test and the estimated Glomerular Filtration Rate (eGFR). Physicians use the results of these tests to determine the status of kidney function, whether kidney disease has developed suddenly or as a long-term process, and the cause of kidney damage. The microalbumin test is a simple measurement to detect protein in the urine. Persistent protein in the urine is a sign of CKD. The eGFR is considered the most accurate way to detect changes in kidney function. An eGFR below 60 is an indication of significant kidney function loss. Tests for eGFR and microalbumin are available at virtually all medical testing laboratories in the U.S.

Study Methodology

The Quest Diagnostics Health Trends(TM) Report is based on an initial review of test results from November 2005 to October 2006, for patients ages 18 and older. Patient matching software was used to assign a "patient matching" identification number, so that a de-identified data set of individual patient results, matched over time, could be created. The de- identified data was then aggregated for analysis. The result was a HIPAA- compliant data set that allowed the company to analyze data on the level of the individual patient, while assuring that patients could not be identified by name, address, physician name, or similar features.

The analysis was based on results of 6.2 million eGFR test and microalbumin test results. Physicians use both tests to evaluate a patient's kidney function and diagnose kidney disease. The 6.2 million test results were comprised of 3.4 million calculated eGFR tests performed in October 2006 and 2.8 million microalbumin test results performed between November 2005 and October 2006. The analysis determined the percentage of patients with significant kidney function loss (eGFR below 60) who had a microalbumin test performed during the previous 12 months.

These patients were then categorized according to patient groups of diabetes or hypertension based on ICD-9 codes. In addition, for some of the patients who did not have an ICD-9 code for diabetes associated with their eGFR or microalbumin results, additional information was obtained if they had hemoglobin A1c (HbA1c) testing. (HbA1c testing is used by physicians to assess diabetes control.) This assessment allowed these patients to be included in the diabetes group. The diabetes and hypertension diagnostic groups were further analyzed by age group (18-70+), gender and geographic area (U.S. state). The calculated eGFR values were determined from the serum creatinine test results according to the Modification of Diet in Renal Disease (MDRD) study formula for patients ages 18 and older. Adjustments for ethnicity were not included in the eGFR calculations used in this study (although Quest Diagnostics provides eGFR results for African-Americans and non-African- Americans to physicians to help them more accurately assess the kidney function of their patients).

Quest Diagnostics Health Trends(TM)

Quest Diagnostics maintains the largest private clinical laboratory data warehouse in the United States. Growing by 9 million data points a day, the database provides laboratory information on the vast majority of conditions and diseases affecting Americans today. Quest Diagnostics provides these data to health plans to help manage the health of their members. Quest Diagnostics Health Trends(TM) Reports identify and track disease and wellness benchmarks. De-identified data are made available as a public service to inform patients, health professionals and policymakers about the current status of the nation's health.

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 healthcare information technology solutions that help improve patient care. Additional company information is available at: www.questdiagnostics.com.

The statements in this press release that 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 2007 Form 10-K and subsequent SEC filings.