Hospital variation in outcomes following appendectomy in a regional quality improvement program.
BACKGROUND
The aim of this study was to determine hospital variation in clinical outcomes after appendectomy for acute appendicitis.


METHODS
Using data from the Michigan Surgical Quality Collaborative, we selected patients with procedure codes for open or laparoscopic appendectomy with a diagnosis of acute appendicitis (2006 to 2011). We used multivariate regression models for risk adjustment of patient-level factors and reliability adjustment for sample size differences between hospitals. Adjusted rates of outcomes for each hospital were generated by multiplying ratios of observed to expected events by overall mean event rates.


RESULTS
During the study period, 12,410 patients underwent appendectomies in 49 participating Michigan Surgical Quality Collaborative hospitals. Neither the mortality rate nor the rate of superficial or deep surgical site infection demonstrated significant variation. However, significant variation was observed for all other clinical outcomes, including a 14-fold difference of the rate of postoperative sepsis and septic shock.


CONCLUSIONS
We found significant hospital variation in outcomes after appendectomy and identified missing variables that could help to explain the observed variation. These findings have been used to enhance ongoing quality improvement efforts across the state of Michigan.
Department of Surgery, Indiana University, North Capitol Avenue, Suite B250, Indianapolis, IN 46202, USA. Electronic address: pjenkins1@iuhealth.org.
Peter C
PC
Jenkins
Department of Surgery, Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI, USA.
Mary K
MK
Oerline
Department of Surgery, Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI, USA.
Andrew J
AJ
Mullard
Department of Surgery, Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI, USA.
Michael J
MJ
Englesbe
Department of Surgery, Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI, USA.
Darrell A
DA
Campbell
Department of Surgery, Center for Healthcare Outcomes and Policy, University of Michigan, Ann Arbor, MI, USA.
Mark R
MR
Hemmila
D000208:Acute Disease; D000328:Adult; D000368:Aged; D001062:Appendectomy / Q000009:adverse effects / Q000379:methods*; D001064:Appendicitis / Q000175:diagnosis / Q000601:surgery*; D016208:Databases, Factual; D005260:Female; D005500:Follow-Up Studies; D006761:Hospitals / Q000639:trends*; D006801:Humans; D010535:Laparoscopy / Q000009:adverse effects / Q000379:methods*; D007813:Laparotomy / Q000009:adverse effects / Q000379:methods*; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology / Q000503:physiopathology; D058996:Quality Improvement; D012044:Regression Analysis; D012189:Retrospective Studies; D016896:Treatment Outcome
Appendectomy; Emergency general surgery; Outcomes; Regional quality improvement