HIMSS Word of the Day #137: Average Length of Stay (ALOS)
Average length of stay (ALOS) is the average number of days inpatients spend in the hospital, a widely used measure of efficiency, capacity, and cost. This post explains how ALOS is calculated, the difference between observed and expected length of stay, why it matters under DRG-based payment, its limits as a quality measure, and how nurses and data help reduce avoidable days.