Inpatient Definitions and Methodology

Trend Report

All information in this report is taken from the Medicare Provider Analysis and Review (MedPAR) file which is updated annually by CMS based on the federal fiscal year.  The file includes billing data for 100% of all Medicare fee-for-service claims for discharges during the twelve months ending September 30.  The report is based on MedPAR data from the four most recent years available and is consistent with CMS Data Release policies.

Medical service categories are based on groupings of patient MS-DRGs.  Click on any medical service in the report to see the MS-DRGs that are summarized to define the category.

The Medicare case mix index (CMI) is based on the Medicare Hospital Inpatient Prospective Payment System for the corresponding federal fiscal year.  The CMI for long term acute care (LTAC) hospitals reflects MS-DRG changes implemented by CMS in FY04.

Medical and Surgical MS-DRGs are defined by CMS.  The percentage of discharges in each is reported in order to provide a perspective of medical versus surgical caseloads over prior years.

Discharge dispositions summarize the destinations of patients after they leave the hospital.  Only dispositions representing more than 10 patients are reported.

Patients discharged from Distinct Part Units (DPUs) are identified separately and are included in the total.

A brief description of the Medicare Prospective Payment System is provided to explain the system, MS-DRGs, the case mix index, etc. 

Medicare Advantage Discharges are contained in MedPAR but are excluded in other reporting on ahd.com (i.e. ahd.com is based primarily on Medicare fee-for-service data). Though the number of discharges reported for Medicare Advantage patients in MedPAR appears to be reliable, the accuracy of other claims data for these patients cannot be verified. Further, CMS has changed the way Medicare Advantage Discharges are identified in MedPAR during recent years and, despite best efforts, a small number of claims may be misidentified during the transition.