[Cost and Revenue Relationship in Orthopaedic and Trauma Surgery Patients in Relation to Body Mass Index].

Background: Growing numbers of patients in orthopaedic and trauma surgery are obese. The risks involved are e.g. surgical complications, higher costs for longer hospital stays or special operating tables. It is a moot point whether revenues in the German DRG system cover the individual costs in relation to patients' body mass index (BMI) and in which area of hospital care potentially higher costs occur.

Material And Methods: Data related to BMI, individual costs and revenues were extracted from the hospital information system for 13,833 patients of a large hospital who were operated in 2007 to 2010 on their upper or lower extremities. We analysed differences in cost revenue relations dependent on patients' BMI and surgical site, and differences in the distribution of hospital cost areas in relation to patients' BMI by t and U tests.

Results: Individual costs of morbidly obese (BMI ≥ 40) and underweight patients (BMI < 18.5) significantly (p < 0.05) exceeded individual DRG revenues. Significantly higher cost revenue relations were detected for all operations on the lower and upper extremities except for ankle joint surgeries in which arthroscopical procedures predominate. Most of the incremental costs resulted from higher spending for nursing care, medication and special appliances. Costs for doctors and medical ancillary staff did not increase in relation to patients' BMI.

Conclusion: To avoid BMI related patient discrimination, supplementary fees to cover extra costs for morbidly obese or underweight patients with upper or lower extremities operations should raise DRG revenues. Moreover, hospitals should be organisationally prepared for these patients.