How differences between the hiv epidemics in sub-saharan

The results of any study must be interpreted cautiously so that causal inference is not extended to a population different from the study participants in important ways. Explain how differences between the HIV epidemics in sub-Saharan Africa and the U.S. may limit the degree to which findings from the male circumcision randomized clinical trials conducted in Africa are generalizable to the U.S. population.