[Methodological problems on the preparation and realization of multicientric field studies on mouth and salivary...

The objectives of multicentric field trials are to provide a base for future revisions of the TNM system in order to ameliorate the existing classifications or to create new ones. The data are collected in a prospective and standardized manner and their evaluation is centralized. Therapy and follow-up in each case are registered at regular intervals and individual treatment is reported according to a standardized and flexible procedure. The particular methodological problem lies in the necessity of aligning the volume and quality of the desired information with the practicability of data collection.