In light of recent recommendations for widespread hepatitis C screening, researchers are calling for clinical trials to determine if that screening would result in greater benefit or harm.

Though the recommendations have vocal support from some experts and advocates, no studies have yet established whether such screening would result in greater benefit than harm to patients, three physicians and an investigative medical journalist explain in the British Medical Journal.

In 2012, the U.S. Centers for Disease Control and Prevention (CDC) recommended that all people born between 1945 and 1965 be screened for hepatitis C. The U.S. Preventive Services Task Force (USPSTF) followed suit in 2013 and the World Health Organization called for expanded screening in 2014. Previously, screening recommendations had focused only on those at high risk of developing the disease, such as intravenous drug users and those who received a transfusion prior to 1992.

In issuing its 2013 recommendations, the USPSTF noted the absence of studies on "long-term harms associated with antiviral regimens" and "the outcomes of treatment in screen-detected patients."

"We have a limited window of opportunity to collect appropriate evidence on whether this [widespread screening] is a good idea," write the authors, which include lead author Jeanne Lenzer, an investigative medical journalist, and physicians Ronald L. Koretz, MD, of David Geffen-UCLA School of Medicine; John P. A. Ioannidis, MD, of Stanford University; and Kenneth W. Lin, MD, of Georgetown University School of Medicine.

One missing piece of evidence, says Georgetown's Lin, is to understand who is most likely to benefit from antiviral medications, many of which come with a hefty price tag.

"We know current medications can result in the virus becoming undetectable in a high number of people after 3 to 6 months, but 80 percent of people with hepatitis C do fine with or without treatment," explains Lin. "We need to know if the treatments have any long-term impact on the remaining 20 percent who are destined to develop liver failure, liver cancer or die from the disease."

The authors report that at least 2.7 million people have hepatitis C in the U.S. Many people with the disease do not have symptoms and are not aware they have it. About 16,000 require a liver transplant or die from hepatitis C each year.

"Since most individuals with hepatitis C never develop symptoms and die with it not of it, exposing these individuals to the harms of treatment with no possible benefit might outweigh benefits for the minority destined to develop end-stage disease," Lin argues.

The authors report having no personal financial interests related to the study.