A) Prevalence of HIV – 1000/10,000 = 0

a) Prevalence of HIV – 1000/10,000 = 0.1 or 10% b) Sensitivity of EIA test – 950/1000 = 0.95 or 95% c) Specificity of EIA test – 180/9000 = 0.02 or 2% d) False positive fraction of EIA test – 180/1130 =0.159 or 15.9% e) False negative fraction of EIA test – 50/8870 = 0.005 or 0.5% f) Positive predictive value of EIA test – 950/1130 = 0.84 or 84% g) Negative predictive value of EIA test – 8820/8870 = 0.994 or 99.4% the chief of the State Drug Abuse Commission has noticed a dramatic increase in AIDS among clients in his intravenous-drug-abuse treatment programs. For planning purposes, he wants to do a voluntary HIV antibody prevalence survey of intravenous-drug-abuse clients and would like to assess the feasibility of using the test results as part of behavior-modification counseling. Based on your calculations in Question 4, do you think that the EIA performs well enough to justify informing test-positive clients in the drug abuse clinics that they are positive for HIV? Clearly explain your answer.