Screening for liver diseases
Benefits outweigh costs for some, but not all, conditions
Screening programs for liver diseases can detect asymptomatic conditions which might have better outcomes if diagnosed and treated earlier. However, such programs can also have undesirable consequences: they can be very costly; they might detect conditions which would never become a problem, they can lead to an array of unnecessary further testing and treatment; and lastly, diagnosis of certain conditions could lead to stigmatization of patients by insurance companies or society at large.
A panel of researchers considered the value and the drawbacks of screening for various liver diseases for an American Association for the Study of Liver Diseases (AASLD) workshop presented at Digestive Diseases Week 2003. Their evaluation is published in the May 2004 issue of Hepatology, the official journal of the AASLD. Published by John Wiley & Sons, Inc., Hepatology is available online via Wiley InterScience at http://www.interscience.wiley.com/journal/hepatology.
Dawn Provenzale of Duke University Medical Center considered the cost-effectiveness of screening programs and found it was rare that screening programs saved money. "A seemingly inexpensive test, if suggested for a large number of subjects, can rapidly become an expensive program," she wrote. "A more expensive test with better operating characteristics (fewer false negatives and false positives) may actually be a better investment."
Mark Hall, of Wake Forest University Medical School, considered the potential for insurance discrimination against patients who are found to have a high genetic risk for certain liver diseases. Some fear that life and health insurers will use the results of genetic blood tests to refuse coverage. So far, there is no data that shows health insurers ask about or consider genetic test results. Still, more than half of all states have passed legislation forbidding health insurers from using predictive genetic test results. Life insurers, on the other hand, "are now routinely using predictive genetic information in the form of family history and argue strenuously that they must be able to consider the results of predictive genetic testing as this technology becomes more commonplace," reports Hall.
Researchers also considered the potential value of screening for a number of specific liver conditions. While screening for hepatocellular carcinoma (HCC) might seem desirable, because the disease is more treatable when caught early, studies have shown that screening costs are very high per year of life saved. Still, hepatologists typically screen high-risk patients, despite a lack of proven value, and will probably continue to do so.
Hemochromatosis has been shown to have a strong genetic component, with men of Northern European ancestry at highest risk, therefore, screening of this population might be considered, the authors advised. For medication-related hepatotoxicity, they said the future of screening lies in pharmacogenomics.
Screening for chronic viral hepatitis (B and C) has been shown to have a positive impact on high-risk populations. It is warranted, the authors say, based on its effectiveness in reducing transmission as well as leading to treatment. However, they note that diagnosis of hepatitis B or C can lead to stigmatization or discrimination. The authors found that screening methods for two other liver conditions -- cirrhosis and portal hypertension -- have not been found to be sufficiently accurate.
In summary, the value of screening varies by condition, and therefore, should be carefully considered before being widely implemented. While it may be able to identify treatable or contagious liver conditions in some patients, it can also harm others by discovering disease that might never cause symptoms and also subjecting patients to invasive evaluations or treatments.
The authors also pointed out a paucity of strong evidence on the value of screening programs for many conditions. "The future will require prospective studies on the efficacy of screening and surveillance to prevent the morbidity and mortality of liver diseases," they conclude. "Many of these studies are already in progress and, despite their limitations, will likely guide our management decisions into the next decade."
Source: Eurekalert & othersLast reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
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