The results confirmed that cumulative experience is a significant predictor of learning, and further reveal that the slope of the learning curve varies significantly across organizations. In their results, they found that initial procedure times varied across hospitals in the sample. They also found an overall tendency for procedure time to fall with cumulative experience. At the same time, they found statistically significant differences in the learning curves across the sample of 16 sites.

The superior surgical team mentioned above had slower than average predicted procedure time for its first seven cases. The models show, however, that by case 50, this team was able to undertake a comparable procedure significantly faster than the typical team in the sample.

The estimated net adjusted procedure time for this hospital at case 50 was approximately 132 minutes, versus 220 minutes for the sample average.

Looking at the data from case 40, the superior hospital's estimated 143-minute time was the shortest net adjusted procedure time in the sample. The largest estimate, 305 minutes, was more than 2.5 hours longer.

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Contact: Barry List
barry.list@informs.org
410-691-7852
Institute for Operations Research and the Management Sciences
7-Aug-2001