> Why didn't they control for the other intervention treatments? One where they reduce BLL + other treatments, and one where they didn't reduce BLL but still ga

> Why didn't they control for the other intervention treatments? One where they reduce BLL + other treatments, and one where they didn't reduce BLL but still gave the other treatments? This is a good question, but keep in mind it's not a randomized control trial, they are using some clever techniques to look backwards on data from an existing program. They could expand the study and compare to other children who had health workers in the home for unrelated reasons. But those unrelated reasons could themselves affect 'antisocial behavior and cognitive outcomes'