AIDS Treatment Center: Is the Concept Premature?-Reply

In Reply.—  We would like to thank Green et al for underscoring both the importance and the limitations of our study. However, we disagree with some of their specific comments. With respect to choice of hospitals for the study, we made no attempt to make a complete survey. Future studies will address these issues. The sample represented hospitals with varied characteristics, and the strength of our results suggest that the conclusions are generalizable.We agree with their view that mortality should be studied on the basis of a fixed time window because of confounding factors such as hospices. In our study, this was unlikely to be a significant factor, as well-developed outpatient networks were not available in the study hospitals during the study years.Finally, we think that Green et al may have misrepresented our policy implications. In our study, we outlined three recommendations that apply to both regionalization and