Context: The use of Roux-en-Y gastric bypass (RYGB) has been reported to be effective in the treatment of obesity and its related comorbidities. Utilization of inpatient services after RYGB is less well understood.

Objective: To determine the rates and indications for inpatient hospital use before and after RYGB.

Design, setting, and participants: Retrospective study of Californians receiving RYGB in California hospitals from 1995 to 2004.

Main outcome measure: Hospitalization in the 1 to 3 years after RYGB.

Results: In California from 1995 to 2004, 60,077 patients underwent RYGB-11,659 in 2004 alone. The rate of hospitalization in the year following RYGB was more than double the rate in the year preceding RYGB (19.3% vs 7.9%, P<.001). Furthermore, in the subset of patients (n = 24,678) with full 3-year follow-up, a mean of 8.4% were admitted a year before RYGB while 20.2% were readmitted in the year after RYGB, 18.4% in the second year after RYGB, and 14.9% in the third year after RYGB. The most common reasons for admission prior to RYGB were obesity-related problems (eg, osteoarthritis, lower extremity cellulitis), and elective operation (eg, hysterectomy), while the most common reasons for admission after RYGB were complications often thought to be procedure related, such as ventral hernia repair and gastric revision. In multivariate logistic regression models predicting 1-year readmission after RYGB, increasing Charlson Comorbidity Index score, and hospitalization in the 3-year period prior to RYGB were significantly associated with readmission within a year.

Conclusions: Increases in hospital use after surgery appear to be related to RYGB. Payers, clinicians, and patients must consider the not-inconsequential rate of rehospitalization after this type of surgery.