Question

Epidemiology help!

(7). Factors A, B, or C can each individually cause a certain disease without the other two factors, but only when followed by exposure to factor X. Exposure to factor X alone is not followed by the disease, but the disease never occurs in the absence of factor X. (3 points) (1) In this case Factor X is (a) Necessary and Sufficient (b) Necessary, but not Sufficient (c) Sufficient but not necessary above (d) Neither Necessary nor sufficient (e) None of the (ii) In this case Factor A (a) Necessary and Sufficient (b) Necessary, but not Sufficient (c) Sufficient but not necessary (d) Neither Necessary nor sufficient (e) None of the above

Answer 1

(1)In this case the X factor is B = necessary but not sufficient

Because all the factors need exposure to X factor prior to cause disease but X factor is not only cause of the disease.

(2) In this case the factor A is (a) Sufficient and necessary

Because factor A can cause disease independently on factor B and C