Canadian Association of Gastroenterology Practice Guidelines: evaluation of abnormal liver enzyme tests.

Approximately one in 10 Canadians has at least one abnormal liver biochemical test on routine screening. Although in the majority of these individuals the abnormality reflects a benign liver condition such as Gilbert’s syndrome or enzyme induction from recent alcohol consumption, a subgroup will have progressive and potentially life-threatening liver disease for which therapeutic interventions are often available (1). The objectives of these guidelines are to, first, outline when screening for liver disease would be appropriate; second, determine which biochemical tests should be used in screening for liver disease; third, review second-line tests for when screening tests are positive; fourth, outline when referrals to specialists would be appropriate; and, fifth, review additional testing that specialists might undertake in their evaluation of the patient. Because sanctioned guidelines for investigating asymptomatic patients with liver biochemical abnormalities have not been developed, the options, outcomes and evidence considered in formulating the present guidelines largely reflect the experience of individuals with expertise in the area and a limited number of clinical studies in which liver biochemical abnormalities were described in the healthy blood donor population as well as in patients with various forms of acute and chronic liver disease. BENEFITS, HARMS AND COSTS The benefits, harms and costs of screening for liver disease can only be estimated on the basis of efficiently arriving at a correct diagnosis (or at least appreciation) of the general form of liver disease (hepatocellular versus cholestatic), avoidance of unnecessary, interventional procedures and efficient use of laboratory testing.