No study has determined whether stepping up screening for hepatitis C will lead to clinical benefit or harm, conclude the authors of an analysis published in The BMJ.

Doctors "should resist screening until we have strong evidence that antiviral therapy is clinically effective and the benefits outweigh the harms," wrote lead author Ronald Koretz, emeritus professor at UCLA School of Medicine.

The Centers for Disease Control and Prevention recommends screening all adults born between 1945 and 1965 for hepatitis C. The U.S. Preventative Services Task Force and the World Health Organization also recommend widespread screening.

Still, most of those with hepatitis C "will not develop end stage liver disease and will therefore be unnecessarily treated," contended Koretz and his co-authors. They “question the validity of using surrogate markers in drug trials to predict long term effects of treatments," and say the ability of therapy to reduce the incidence of end stage liver disease is unproved, according to a press release. 

The authors also argued that, "Given the uncertainty about the validity of the surrogate markers, the lack of evidence regarding clinical outcomes of treatment or of screening strategies, and the adverse events caused by the newer regimens, screening may be premature." 

Because of this, “physicians should resist screening until we have strong evidence that antiviral therapy is clinically effective and the benefits outweigh the harms," the authors concluded. “Claims of increased safety or tolerability of the newer treatment have been based on fewer and less severe side effects. However, the new drugs can still cause serious adverse events (resulting in persistent disability, hospital admission, or death),” they explained.