by John Gever, Senior Editor, MedPage Today
October 13, 2010
Testosterone measurements are frequently inaccurate, due in large part to lack of standards for performing the assays -- a situation that must change -- the Endocrine Society and 10 other groups declared in a consensus statement.
"Testosterone assays are widely used in clinical research, epidemiological studies, and patient care. However, deficiencies in these assays limit their broad and effective implementation and threaten the health of those patients whose medical care relies upon accurate measurement of testosterone," wrote William Rosner, MD, of St. Luke's-Roosevelt Hospital Center in New York City, and Hubert Vesper, PhD, of the CDC, on behalf of the organizations.
They called on all stakeholders -- physicians, clinical laboratories, instrument makers, insurers, government, and patient groups -- "to formulate plans to implement accuracy-based, calibrated testing across the entire community of providers and users of these assays."
The statement, which suggests that reliable inter-laboratory testing is possible within two years, was published in the October issue of the Journal of Clinical Endocrinology and Metabolism.
The statement resulted from a conference held last February in Atlanta, attended by more than two dozen representatives of the endocrinologist societies, FDA, CDC, and major clinical labs.
The consensus statement noted that the underlying problem is the lack of a single, agreed-upon standard method for measuring testosterone in serum or plasma, according to the consensus statement.
"Consequently, many widely used tests do not provide accurate results across the range of testosterone concentrations applicable to patient care," Rosner and Vesper noted in the statement, particularly at low concentrations,
Back in 2007, the CDC began a project to develop a workable standard for testosterone assays.
Since then, CDC researchers have collaborated with academics and industry scientists to develop reference materials and calibration and verification procedures, with much of the work already completed.
They have also conducted studies to demonstrate the variability in results obtained with the different methods in current use.
However, further progress requires cooperation from instrument makers, clinical labs, and other stakeholders, the consensus statement indicated.
"It is important that the broader scientific and medical communities demand accuracy-based standards for testosterone assays, that manufacturers and laboratories provide accurate and reliable tests, and that research funding agencies and third-party payers reimburse accordingly," Rosner and Vesper wrote in the statement.
Work also remains to be done within the technical community, they indicated. Performance criteria and reference intervals covering "the full range of expected values, from children to adult males and females," must also be established and validated.
Guidelines for patient preparation and specimen handling must also be developed, Rosner and Vesper indicated.
Medical journals and research funders also have a role to play, they added.
"Journals should accept only research results that are based on high-quality, standardized tests, the results of which are based on demonstrable accuracy," Rosner and Vesper wrote. "When selecting tests for patient care and research, or when supporting research and public health activities, an assessment of whether tests are standardized to CDC should become part of the selection and support granting process."
The consensus statement included a timeline suggesting that standardization of testosterone assays could be achieved by 2012.
Next year, it projected, "broad participation" by assay manufacturers and clinical labs should be achieved, and refinement of performance criteria should be finished.
By 2012, physicians should be able to order tests meeting the new uniform standard, and reference intervals for interpreting the results should be available.
The statement also indicated that the performance criteria should be reevaluated every two to four years thereafter.
In addition to the Endocrine Society, organizations signing on to the statement included the American Association of Clinical Endocrinologists, the American Association for Clinical Chemistry, the American Society for Bone and Mineral Research, the American Society for Reproductive Medicine, the American Urological Association, and the North American Menopause Society.
Solvay Pharmaceuticals funded the project through the CDC Foundation.
Funding was also provided by the National Center for Environmental Health and the Division of Cancer Prevention and Control at the National Center for Chronic Disease Prevention and Health Promotion.
Employees of Laboratory Corp. of America, Quest Diagnostics, and Solvay participated in the workshop that drafted the consensus statement.
No other potential conflicts of interest were reported.
Primary Source
Journal of Clinical Endocrinology and Metabolism
Source Reference: Rosner W, et al "Toward excellence in testosterone testing: A consensus statement" J Clin Endocrinol Metab 2010; 95: 4542-4548.