Impact of body mass index on clinical and cost outcomes after radical cystectomy

OBJECTIVE To evaluate the effect of body mass index (BMI, kg/m²) on the cost and clinical variables after radical cystectomy (RC), as studies show that obesity might adversely affect the outcomes after RC. PATIENTS AND METHODS The charts of patients who had RC from January 2004 to March 2007 were reviewed retrospectively. Complete cost and clinical information was available for 99 patients; the patient and tumour characteristics and peri-operative outcomes were recorded. Detailed cost information (room and board, laboratory, pharmacy, radiology, operating room, surgical supply, anaesthesia, and recovery room) was obtained from hospital billing. Patients were stratified and compared in three groups of BMI, i.e. normal weight (<25), overweight (25-<30) and obese (≥30). RESULTS The mean age of the patients was 66 years; 27% were normal weight, 38% were overweight and 34% were obese. Of obese patients, 24% had an Eastern Cooperative Oncology Group performance score of 0, vs none and 2.6% in the normal and overweight groups, respectively (P = 0.001). Those of normal weight had the highest overall and major complication rates (P = 0.57 and 0.28, respectively). Obese patients had insignificantly higher transfusion rates (P = 0.28). The direct cost was higher in normal weight ($14 314) than overweight ($13 808) and obese ($13 666) patients (P = 0.47). Higher room and board cost in normal-weight patients was the only significant cost difference (P = 0.008). CONCLUSION BMI was not associated with increased costs of cystectomy. The absence of differences in cost-related and clinical outcomes might be attributable to variable comorbidity among groups and the experience of a high-volume surgeon and staff at a tertiary-care referral centre that routinely cares for obese patients.