Length of stay is a term commonly used to measure the duration of a single episode of hospitalization. Inpatient days are calculated by subtracting day of admission from day of discharge

Discharge

Discharge in the context to expel or to "let go" may refer to:* A military discharge, issued when a member of the armed forces is released from service* Termination of employment, the end of an employee's duration with an employer...

. However, persons entering and leaving a hospital on the same day have a length of stay of one. (See hospital.)

A popular statistic associated with length of stay is the average length of stay (ALOS), calculated by dividing the sum of inpatient days by the number of patients admissions with the same DRG

Diagnosis-related group

Diagnosis-related group is a system to classify hospital cases into one of originally 467 groups. The 467th was "Ungroupable." The system of classification was developed as a collaborative project by Robert B Fetter, PhD of the Yale School of Management, and John D Thompson, MPH of the Yale...

 classification.

A variation in the calculation of ALOS could be consider only length of stay during the period under analysis.

The prospective payment system

Prospective payment system

A prospective payment system is a means of determining insurance payments based on predetermined prices, commonly from Medicare. Payments are typically based on codes provided on the insurance claim.Examples of these codes include:...

 in U.S. Medicare for reimbursing hospital

Hospital

A hospital is a health care institution providing patient treatment by specialized staff and equipment. Hospitals often, but not always, provide for inpatient care or longer-term patient stays....

care promotes shorter LOS by paying the same amount for procedures, regardless of days spent in the hospital.