We developed a model to measure the contribution of changes in length-of-st
ay, service intensity, and productivity to the unusually low rate of growth
in hospital costs per discharge in recent years. From 1992 through 1996 de
clining length-of-stay explained 97 percent of the decrease in real costs p
er discharge, Much of the drop was probably caused by care shifted from inp
atient to postacute settings. Although complete data for our model are unav
ailable beyond that point, we cite several "leading indicators" that sugges
t that length-of-stay declines have played a smaller role in the continued
low cost growth of 1997 and 1998 and that productivity may have risen sharp
ly.