Pitfalls in interpretation of large registry data on hernia repair.

Since more and more hernia registries are being created and the number of patients included is increasing, knowledge of potential pitfalls in interpretation of registry data has to be known and dealt with. This invited commentary is to discuss some of these topics. The aim is to present and discuss the main shortcoming of register-based studies and how to deal with these problems, to contribute to more validated results and eventually improved surgical outcomes.