Introduction

Transfers can be defined using an algorithm, such as the _EPISODE macro (see SAS Code and formats below (internal access only) ) and/or the Transfer From/Transfer To variables in the Hospital Discharge Abstract data.

Discussions with programmers determined that it is unlikely, given how project needs can vary, that a standard transfer algorithm can be used. It is important for both investigators and programmers to be aware of the issues to consider when choosing the most appropriate definition for a study.

Some points to consider are:

• Transfers should be distinguished not only from readmissions but also from episodes.
  
• Remember for Transfer From and Transfer To claim variables that Personal Care Homes are included, and some consideration should be given as to whether to define these as transfers.
  
• You need to go to claims from fiscal years beyond your study period in order to identify transfers accurately when using a transfer algorithm.

Some reasons for identifying transfers:

1. Not to overcount diagnoses or procedures.
   
2. Not to undercount diagnoses or procedures (e.g.: if you are selecting Length of Stay > 0 for your study, you may miss a procedure on an initial claim).
   
3. When a standard length of stay is needed (e.g.: stays less than 30 days).

Example

It was decided for the costing project to define transfers using the Transfer To and Transfer From variables on the hospital datasets, but to exclude transfers from certain institutions:

• urban extended care
  
• rural extended care
  
• Eden mental health
  
• extended treatment facilities
  
• Personal Care Home (PCH) facilities

NOTE

The differences between using the Transfer To and Transfer From variables and using an algorithm which captures cases where the same person was discharged from one hospital and then admitted to a different hospital within one day, have been examined. There was 96.4% agreement between the two methods, and the differences are discussed in Transfer Definitions (internal access only) .

In addition, beginning in 1996/97, the Health Science Centre (HSC) Health Records department is "splitting" abstracts for Rehabilitation patients. When a patient is transferred from the general hospital to the rehabilitation hospital, they are discharged and transferred, with the Transfer To and Transfer From variables both indicating HSC. This can affect the case counts (i.e.: where one continuous episode of care can look like 2 or more separations). This situation is not all that common, but depends on the patient's condition.

CAUTIONS

• If you are going to use the Transfer To and Transfer From variables, the order of variables is important for matching the records. The required sort order for the Hospital Discharge Abstract Database is Personal Health Number, Admit Date and Discharge Date.
  
• The Hospital Discharge Abstract Database is actually stored by Personal Health Number, Admit Date and descending Discharge Date. This means an additional sorting step will be required to put the database variables in the proper order.