Healthcare and pharma
Average length of stay (ALOS)
The average number of days patients stay in hospital per admission.
Last reviewedWhat does Average length of stay (ALOS) mean?
Average length of stay is total inpatient days divided by the number of admissions (or discharges) in a period. Shorter stays, when safe, free beds for more patients and cut cost per case, which matters most when payers pay a fixed amount per admission, as with DRGs. Example: a 200-bed hospital at 85 percent occupancy has 170 beds filled each day. At an ALOS of 5 days it admits 34 new patients a day, but at 4 days it can admit 42.5, a 25 percent rise from the same beds. This is Little's law at work. The OECD publishes average length of stay by country in its health statistics.
Where does it come up in case interview prep?
Related terms
- Little's lawItems in a system = arrival rate × time each item spends in it.
- DRG (diagnosis-related group)A system that pays hospitals a fixed amount per admission, based on the diagnosis and treatment.
- ARPOB (average revenue per occupied bed)Hospital revenue divided by occupied bed days, a key measure for Indian hospital chains.
- Capacity utilizationActual output as a share of the most that could be produced.
- Occupancy rateThe share of available rooms (or beds) that are filled over a period.
- Loss of exclusivity (LOE)When a drug's patents and other protections end and cheaper copies can launch.
- BiosimilarA near copy of a biologic medicine, approved as having no meaningful clinical difference.
- CapitationPaying a provider a fixed amount per person per period, whatever care they use.