The costs of providing health care have skyrocketed over the last twenty years.  At the same time the incidence of infections, especially antibiotic-resistant infections, contracted during hospitalization have increased significantly.  States have recognized the impact of these secondary (not existing upon admission) infections on health care costs, and some have introduced legislation to reduce payments to hospitals with high rates of secondary infection.   Clearly it is in everyone’s best interest to reduce the incidence of infections contracted during hospitalization.  But, this is a difficult problem to solve due to interactions among the various pathogens, categories of illness of the patients and occupancy rate of the hospital.  In other words, it is hard to know “where to start.”  However, researchers worked with Cook County Hospital in Chicago to build simulations to represent various scenarios of these variables so they could study the relative efficacy of improved hand-hygiene protocols vs. changes in patient isolation policies.  They found both policies could have a significant impact on the rate of infections.  However, when they also examined the costs – both to the patient and to the hospital – under various conditions, they determined that improved hand-hygiene protocols were more appropriate as a first approach to solving the problem.  Further, the researchers provided insights into conditions where the policies should be changed and what the associated costs would be.