The model was premised on hospital inpatient data, at the US population level, on four chronic conditions typically managed in disease management: asthma, acute myocardial infarction, congestive heart failure, and diabetes mellitus. As inpatient utilization represents the single largest health expenditure (30% in 2004),[2] it is logical to focus on reducing hospitalizations as a means of achieving large cost savings. Similarly, as approximately 14% of emergency department visits result in hospital admission,[3] it is reasonable to target emergency department utilization as well. Moreover, disease management programs have been unable to consistently control financially-related outcomes beyond hospital admissions and emergency department visits.[4] This result is not surprising, as physician encounters and pharmacy utilization are both likely to increase as a result of a successful disease management
interventions based on evidence-based practice guidelines.[4]