What factor does NOT contribute to changes in case-mix index (CMI)?

The case-mix index (CMI) is a measure used to determine the relative complexity of cases treated by a healthcare facility. It reflects the diversity and clinical complexity of the patient population and is influenced by several factors related to the clinical environment.

Coding productivity itself does not directly affect the CMI. While efficient coding may ensure that services are captured and billed appropriately, it does not inherently change the types of cases treated or their associated resource requirements. In other words, an increase in coding productivity might result in more cases being coded quickly, but unless these cases represent a more complex mix of diagnoses and procedures, the overall CMI would remain unaffected. Instead, CMI changes are more significantly influenced by the nature of the medical cases handled, the coding accuracy, and the complexity of the services rendered.

Conversely, changes in medical staff composition can lead to shifts in the types of services provided and the patient populations treated, which may contribute to variations in CMI. Similarly, changes in coding rules can alter how cases are categorized, impacting the calculations that form the CMI. Lastly, changes in services offered can also lead to a different mix of patient cases, thus affecting the CMI. Therefore, while coding productivity is important for operational efficiency, it does