[The learning curve in surgery: possibilities and limits of this method]

The learning curve is a graphic representation of the relationship between the experience of a surgeon and one or more performance indicators. The operation time alone is an insufficient indicator to assess the performance of a surgeon. The procedure time has to be set in relation to the complication rate and in laparoscopic surgery to the conversion rate. Techniques to visualize the changes over time are the moving average method for the operation time and the Cusum method for dichotomous outcomes, like the conversion and the complication rates. At the time when the learning curve reaches the plateau phase this representation can be used to assess the quality of a surgeon or a team in one hospital. As far as there is no validated complexity scale for laparoscopic procedures available it is difficult to compare patient populations between different hospitals. Out of this reason the learning curve is no legitimate instrument to rank surgeons or different hospitals.