Researchers working with the Research Identifiable (RIF) versions of the MedPAR or Inpatient and Skilled Nursing Facility (SNF) claims may find records that do not appear to correspond to the year of the file. These instances can usually be explained by how stays or claims are included in the files during file creation. The RIF MedPAR file contains both short and long hospital stays as well as SNF stays. The process for inclusion in the MedPAR will vary by the type of stay.
The Limited Data Set versions of the Medpar do not follow these inclusion rules.
Short stay hospital and long stay hospital records are included in the RIF MedPAR file based on the year of discharge. Therefore, it is possible to see a hospital stay with an admission date from the prior year, particularly if it is a stay that started at the end of the year.
For example, if a beneficiary is admitted on December 26th, 2011 and is discharged on January 3, 2012, the stay will be included in the 2012 MedPAR file.
SNF stays in the MedPAR are included in the MedPAR file based on the year of admission.
For example, if a beneficiary is admitted to a SNF on December 26, 2011 and is discharged on January 2, 2012, the stay will be included in the 2011 SNF file.
In regards to the claim files (Standard Analytical Files), both the Inpatient and SNF claims will include claims based on the year of the claim thru date (similar to the short and long stays in the MedPAR file). If a hospital stay or SNF stay involve multiple claims and these claims span two years, it is possible then to see claims associated with the same inpatient or SNF stay in two different years of the inpatient or SNF files.