What could most likely explain an increase in a facility's case-mix index?

An increase in a facility's case-mix index typically indicates that the complexity and resource needs of the patients being treated have risen. The case-mix index is a measure that reflects the diversity, clinical complexity, and resource consumption associated with patient populations within a healthcare facility.

Improvements in the quality of clinical documentation can play a significant role in this increase. When clinicians provide more detailed and accurate documentation of patient conditions, diagnoses, and treatments, it can lead to the coding of more complex cases. This enhanced documentation ensures that the severity of the patients’ illnesses and the intensity of care required are appropriately captured, which can elevate the case-mix index. A higher case-mix index suggests that the hospital is treating more severe or complicated cases, potentially leading to better reimbursement rates under various payer models.

The other options, while they can affect various aspects of healthcare performance, do not inherently relate to the complexity of the patient population in the same way. For example, reduced patient numbers might lead to a lower case-mix index due to fewer complex cases being treated. Increased costs may reflect higher spending without necessarily changing the types of cases treated, and higher hospital readmission rates might indicate quality issues rather than an increase in the complexity of cases. Hence,