Which index includes a list ordered by diagnosis code number for discharged patients?

The correct answer is the index that features a list organized by diagnosis code number for discharged patients. This type of index is crucial for various purposes, such as data retrieval, coding and billing, research, and epidemiology. The disease index specifically catalogues patients based on their diagnoses, facilitating the identification of patterns related to specific conditions.

The disease index typically allows healthcare professionals to track the occurrences of various diseases within a facility. It serves as a valuable tool for analyzing disease trends and understanding the patient population's health needs. By ordering entries by diagnosis code, the index enhances efficiency in locating and retrieving patient data related to specific conditions, which is especially important for quality improvement initiatives, reporting, and compliance with regulatory requirements.

Other options serve different functions. The physician index focuses on categorizing discharged patients based on their attending physicians, while the master patient index deals with maintaining a comprehensive list of all individuals receiving care at the facility, ensuring that records are correctly matched with patients. The operation index, on the other hand, organizes information based on surgical procedures performed, not diagnoses. Thus, the disease index is uniquely positioned to provide insights related specifically to diagnosis codes, making it the relevant choice in this context.