Background: Chronic hepatitis C virus infection is mostly asymptomatic, so it will not be identified if specific diagnostic tests are not performed.
Aims: To evaluate the positive predictive value of some risk factors in detecting anti-hepatitis C virus-positive subjects in the general population.
Subjects: Two-thousand five hundred and sixty-one subjects randomly selected from the list of the census in three population-based surveys performed in hepatitis C virus endemic areas in Southern Italy.
Methods: The sensitivity, specificity and positive predictive value of blood transfusion, past use of glass syringes and surgical intervention in detecting hepatitis C virus positivity were assessed. Data were collected using a precoded questionnaire administered by an interviewer.
Results: All risk factors showed a poor positive predictive value (ranging from 21.0% for surgical intervention to 29.0% for blood transfusion). The positive predictive value was extremely low (ranging from 2.9 to 4.3%) in subjects younger than 46 years of age, who mostly could benefit from antiviral treatment. The combination of the simultaneous presence of more than one risk factor does not improve the detection of hepatitis C virus infection.
Conclusions: Reported risk factors are useless in detecting hepatitis C virus-positive subjects in the general population.