[Two or three things about the PMSI in stomatology and maxillofacial surgery].

The Information Systems Medicalization Program (PMSI in French) was created in 1985 for Public Health Service Hospitalisation Structures. It appeared to be directly derived from the North-American Diagnosis Related Groups (DRGs) system. Since them, the PMSI has been progressively developed in private structures as well. The authors have had the opportunity to use the latest version of the computer program which was elaborated in order to share the patients into more than 500 different groups of pathology. These groups were called "Homogeneous Patients Groups" (GHM in French). To each group corresponds a "Synthetic Activity Index" number (ISA in French). It is supposed to be representative of the average cost of the management of each kind of patients, based on the diagnosis and the surgery possibly done. Several astonishing findings have been made. Some of them can be summarized as mentioned below: In maxillofacial Surgery, each group (GHM) seems in fact to be extremely inhomogeneous: for example, total parotidectomy with preservation of the facial nerve belongs to the same group as accessory salivary gland exeresis. Total skin graft is in the same group as free composite osseous flap with vascular anastomosis. Coding a surgical procedure leads often to reduce the ISA number in comparison with the same patient without surgery: "impacted third molar" gives 754 points without surgery but only 658 if surgery is performed. Carcinologic surgery is wholly grouped in the same category, even for rather short procedures as isolated partial glossectomy. This group corresponds to a great number of ISA points (6486) while bimaxillary surgery or free flap transfer gives less than 2500 points. In conclusion, the use of the PMSI to allocate financial means can be extremely dangerous for maxillofacial surgery units and consequently for the quality of the medical care in our Specialty. Further studies are obviously necessary to complete a critical analysis of the current system and to improve it.