title: End-stage renal disease increases the risk of mortality after appendectomy.
abstract: BACKGROUND
  With each passing year, the number of patients with end-stage renal disease (ESRD) is increasing steadily, but there are limited data on the postoperative outcomes of these patients after appendectomy.
  
  
  METHODS
  Using the Nationwide Inpatient Sample, we identified all patients who underwent appendectomy in the United States between 1998 and 2010. We used International Classification of Diseases, 9th Revision, Clinical Modification codes to identify patients with ESRD and to track postoperative complications during hospital admission. Statistical models were controlled for age, sex, race, insurance type, number of Elixhauser comorbidities, year of admission, perforation of the appendix, and operative approach.
  
  
  RESULTS
  The study population included 5,712 patients with ESRD, with the remaining 3,615,391 patients serving as reference controls. Patients with ESRD had risk of death that was nearly 5 times greater than controls (odds ratio [OR] 5.68; 95% confidence interval [95% CI] 3.96-8.15; P < .001); this risk was similar for nonperforated (OR 4.97; P < .001) and perforated (5.96; P = .004) appendicitis. The risk of death, however, was greater for open appendectomy (OR 6.65; P < .001) compared with laparoscopic appendectomy (OR 2.50; P = .060). Patients with ESRD also were at an increased risk of mechanical wound complication (OR 1.58; P = .040) and had a mean duration of stay that was 34% greater compared with controls (P < .001).
  
  
  CONCLUSIONS
  Patients with ESRD undergoing appendectomy were at an increased risk of death. These patients also had an increased risk of mechanical wound complications and had a greater duration of hospital stay. Future studies should investigate the specific causes of death among patients with ESRD after appendectomy and optimal management strategies in this subset of patients.
authors.affiliation: Department of Surgery, SUNY Downstate Medical Center, Brooklyn, NY. Electronic address: michael.smith@downstate.edu.
authors.forename: Michael C
authors.initials: MC
authors.lastname: Smith
authors.affiliation: Department of Surgery, SUNY Downstate Medical Center, Brooklyn, NY; Department of Epidemiology and Biostatistics, SUNY Downstate School of Public Health, Brooklyn, NY.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Boylan
authors.affiliation: Department of Surgery, SUNY Downstate Medical Center, Brooklyn, NY.
authors.forename: Sophia F
authors.initials: SF
authors.lastname: Tam
authors.affiliation: Department of Surgery, SUNY Downstate Medical Center, Brooklyn, NY.
authors.forename: Roseanna
authors.initials: R
authors.lastname: Lee
authors.affiliation: Department of Surgery, SUNY Downstate Medical Center, Brooklyn, NY.
authors.forename: Antonio E
authors.initials: AE
authors.lastname: Alfonso
authors.affiliation: Department of Surgery, SUNY Downstate Medical Center, Brooklyn, NY.
authors.forename: Gainosuke
authors.initials: G
authors.lastname: Sugiyama
mesh_terms: D000328:Adult; D000368:Aged; D001062:Appendectomy / Q000379:methods / Q000401:mortality*; D001064:Appendicitis / Q000150:complications / Q000401:mortality / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D006801:Humans; D007676:Kidney Failure, Chronic / Q000150:complications*; D010535:Laparoscopy / Q000401:mortality; D007902:Length of Stay; D016014:Linear Models; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors; D016896:Treatment Outcome; D014481:United States