title: Acute Appendicitis in the Adult Population: Modelled Decision Analysis Supports a Conservative Approach.
abstract: BACKGROUND
  Acute appendicitis represents the commonest cause of acute intra-abdominal pathology. Appendectomy and antibiotics are the mainstay of therapy for appendicitis. Evidence is emerging that antibiotics alone may adequately treat most cases of appendicitis. Decision analysis is a quantitative method of examining alternate treatment strategies. This study describes a modelled decision analysis comparing operative and conservative management of appendicitis.
  
  
  METHODS
  The base case patient is a healthy, 23-year-old male presenting with migratory pain to the right iliac fossa (RIF) and elevated inflammatory markers. A decision tree was constructed comparing operative and conservative treatment. Rates of complications, failure of conservative therapy, recurrence and utilities were calculated via a systematic literature review. Variables were tested for sensitivity.
  
  
  RESULTS
  Overall, conservative management gives a significantly better outcome (51.51 vs 49.87 QALYs). Three variables proved sensitive. Once operative complication rates are lower than 11.5 %, surgical treatment becomes the optimal strategy. If rates of failure of conservative management exceed 12.9 %, surgery becomes optimal. If the utility assigned to a post-operative complication exceeds 0.44, surgery becomes optimal.
  
  
  CONCLUSIONS
  This decision analysis supports a conservative strategy, albeit with caveats. If operative complications are low or rates of failure of conservative management remain high, surgery is the preferable strategy.
authors.affiliation: Department of Surgery, Mayo General Hospital, Saolta University Hospital Group, Castlebar, Co Mayo, Ireland. jarbolger@rcsi.ie.
authors.forename: Jarlath Christopher
authors.initials: JC
authors.lastname: Bolger
authors.affiliation: Department of Surgery, Mayo General Hospital, Saolta University Hospital Group, Castlebar, Co Mayo, Ireland.
authors.forename: Michael Eamon
authors.initials: ME
authors.lastname: Kelly
authors.affiliation: Department of Surgery, Mayo General Hospital, Saolta University Hospital Group, Castlebar, Co Mayo, Ireland.|Discipline of Surgery, National University of Ireland Galway, Galway, Ireland.
authors.forename: Kevin
authors.initials: K
authors.lastname: Barry
mesh_terms: D000208:Acute Disease; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001062:Appendectomy; D001064:Appendicitis / Q000601:surgery*; D000066491:Clinical Decision-Making; D003661:Decision Support Techniques; D003663:Decision Trees; D006801:Humans; D008297:Male; D019057:Quality-Adjusted Life Years; D012008:Recurrence; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents
keywords: Acute appendicitis; Conservative management; Decision analysis