The Application of Comorbidity Indices to Predict Early Postoperative Outcomes After Laparoscopic Roux-en-Y Gastric Bypass: A Nationwide Comparative Analysis of Over 70,000 Cases

Abstract

Background

Patients undergoing laparoscopic Roux-en-Y gastric bypass (LRYGB) often have substantial comorbidities, which must be taken into account to appropriately assess expected postoperative outcomes. The Charlson/Deyo and Elixhauser indices are widely used comorbidity measures, both of which also have revised algorithms based on enhanced ICD-9-CM coding. It is currently unclear which of the existing comorbidity measures best predicts early postoperative outcomes following LRYGB.

Methods

Using the Nationwide Inpatient Sample, patients 18 years or older undergoing LRYGB for obesity between 2001 and 2008 were identified. Comorbidities were assessed according to the original and enhanced Charlson/Deyo and Elixhauser indices. Using multivariate logistic regression, the following early postoperative outcomes were assessed: overall postoperative complications, length of hospital stay, and conversion to open surgery. Model performance for the four comorbidity indices was assessed and compared using C-statistics and the Akaike’s information criterion (AIC).

Results

A total of 70,287 patients were included. Mean age was 43.1 years (SD, 10.8), 81.6 % were female and 60.3 % were White. Both the original and enhanced Elixhauser indices modestly outperformed the Charlson/Deyo in predicting the surgical outcomes. All four models had similar C-statistics, but the original Elixhauser index was associated with the smallest AIC for all of the surgical outcomes.

Conclusions

The original Elixhauser index is the best predictor of early postoperative outcomes in our cohort of patients undergoing LRYGB. However, differences between the Charlson/Deyo and Elixhauser indices are modest, and each of these indices provides clinically relevant insight for predicting early postoperative outcomes in this high-risk patient population.

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Conflicts of Interest

All contributing authors, including Jin Hee Shin, Mathias Worni, Anthony W. Castleberry, Ricardo Pietrobon, Philip A. Omotosho, Mina Silberberg, and Truls Østbye, declare that they have no conflicts of interest in relation to this manuscript.

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Correspondence to Truls Østbye.

Appendix

Appendix

  ICD-9-CM code
Postoperative complications
Mechanical wound complications
 Postoperative hematoma 998.12
 Postoperative seroma (noninfected) 998.13
 Disruption of operative wound 998.3
 Disruption of wound unspecified 998.30
 Disruption of internal operation (surgical) wound 998.31
 Disruption of external operation (surgical) wound 998.32
 Persistent postoperative fistula 998.6
 Delayed wound healing 998.83
Infections
 Postoperative infection 998.5
 Postoperative infected seroma 998.51
 Postoperative skin abscess/infection 998.59
 Postoperative septic wound complications 998.59
 Postoperative intraabdominal/subdiaphragmatic abscess 998.59
Urinary/renal complications
 Postoperative urinary retention 997.5
 Postoperative urinary tract infection 997.5
 Acute renal failure 997.5
Pulmonary complications
 Postoperative acute pneumothorax 512.1
 Postoperative pulmonary edema 518.4
 Adult respiratory distress syndrome following surgery 518.5
 Transfusion-related acute lung injury 518.7
 Postoperative atelectasis/pneumonia 997.3
 Mendelson syndrome resulting from a procedure 997.3
Gastrointestinal complications
 Postoperative vomiting 564.3
 Diarrhea following gastrointestinal surgery 564.4
 Postoperative small bowel obstruction/ileus (requiring nasogastric tube) 997.4
 Complication of anastomosis of gastrointestinal tract 997.4
Cardiovascular complications
 Postoperative hypotension 458.29
 Postoperative stroke 997.02
 Cardiac arrest/insufficiency during or resulting from a procedure 997.1
 Phlebitis or thrombophlebitis from procedure 997.2
Systemic complications
 Postoperative shock 998.0
 Postoperative fever 998.89
 Unspecified complication of procedure, not elsewhere classified 998.9

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Shin, J.H., Worni, M., Castleberry, A.W. et al. The Application of Comorbidity Indices to Predict Early Postoperative Outcomes After Laparoscopic Roux-en-Y Gastric Bypass: A Nationwide Comparative Analysis of Over 70,000 Cases. OBES SURG 23, 638–649 (2013). https://doi.org/10.1007/s11695-012-0853-3

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Keywords

  • Laparoscopic Roux-en-Y gastric bypass
  • Comorbidity
  • Charlson/Deyo index
  • Elixhauser index
  • Postoperative outcomes