Figure 1.

Flow diagram of included studies. ^aAfter initial review, a second search was conducted with additional terms, as described in the methods. ^bProQuest records followed a slightly different screening process because many dissertations comprised 3 standalone studies. In an initial review of titles and abstracts, records that were clearly not US setting or relevant were excluded. Remaining records followed the title/abstract and full-text screening process using the hierarchical screening criteria. ^c As described in the methods, the original search strategy included studies of HIV, sexually transmitted infections (STIs), and tuberculosis. However, tuberculosis studies were subsequently excluded because the analyses of the effectiveness of disease intervention specialist (DIS) activities for tuberculosis were too dissimilar from that for HIV and STIs to allow for meaningful comparisons.