The number of patients a hospital treats for a condition or procedure and the severity of a patient's illness when they check into a hospital are two factors that can affect a hospital's quality rating.
Some evidence suggests that the quality of care for patients with certain conditions or procedures is related to the number of patients treated at that hospital for those conditions or procedures, especially if the procedure is risky or extremely difficult.
Severity of illness
The severity of a patient's illness is also a key factor in measuring the quality of care at a hospital. A standard measure to compare patients' severity of illness between hospitals is called the Case Mix Index (CMI). Hospitals with a high CMI treat a greater number of severely ill patients, which impacts overall clinical outcomes.