title: Prospective randomized trials affect the outcomes of intraabdominal infection.
abstract: OBJECTIVE
  To compare the characteristics and outcomes of patients with intraabdominal infections enrolled in prospective randomized trials (PRTs) with those of a cohort of patients not enrolled in a trial.
  
  
  BACKGROUND
  Prospective randomized trials are the gold standard for the evaluation of new treatments. Patients are screened using rigorous eligibility criteria and sometimes are excluded from PRTs because of associated medical conditions or more severe illness. However, the effect that the exclusion of these patients has on the applicability of clinical trial outcomes has not been defined.
  
  
  METHODS
  One hundred sixty-eight adults with intraabdominal infection were treated at a single institution during 7 years. Fifty-three patients were enrolled in four PRTs comparing various antibiotic regimens for treatment; 115 were not enrolled. Patient characteristics and outcomes of these two groups were compared.
  
  
  RESULTS
  Patients with infections from appendicitis (n = 68) had a low severity of illness and similar outcomes in both groups. These patients and those for whom a concurrent PRT was unavailable were excluded from subsequent analysis. Eighty-eight patients (42 PRT, 46 not enrolled) with serious infection remained for analysis. Patients enrolled in PRTs were younger, had less severe illness, had a decreased length of stay, a lower incidence of antibiotic resistance, and less frequent extraabdominal infections than those not enrolled in a trial. Patients enrolled in PRTs were more likely to be cured and were less likely to die. Logistic regression analysis demonstrated that cure was associated with a lower initial severity of illness, absence of antibiotic resistance, and participation in a PRT.
  
  
  CONCLUSIONS
  Patients with intraabdominal infection enrolled in PRTs have an increased likelihood of cure and survival. This is due in part to a lower incidence of antibiotic resistance, which may reflect improved drug selection. Patients not enrolled in PRTs are at greater risk for treatment failure and death because of concomitant illness. Outcomes from PRTs may not be applicable to all patients with intraabdominal infections.
authors.affiliation: Department of Surgery, MetroHealth Medical Center Campus, Case Western Reserve University, Cleveland, Ohio 44109, USA.
authors.forename: J I
authors.initials: JI
authors.lastname: Merlino
authors.forename: M A
authors.initials: MA
authors.lastname: Malangoni
authors.forename: C M
authors.initials: CM
authors.lastname: Smith
authors.forename: R L
authors.initials: RL
authors.lastname: Lange
mesh_terms: D000005:Abdomen; D018784:Abdominal Abscess / Q000188:drug therapy; D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000900:Anti-Bacterial Agents / Q000627:therapeutic use*; D001064:Appendicitis / Q000188:drug therapy; D005260:Female; D006801:Humans; D007239:Infections / Q000188:drug therapy* / Q000473:pathology; D007902:Length of Stay; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D010538:Peritonitis / Q000188:drug therapy; D011446:Prospective Studies; D016032:Randomized Controlled Trials as Topic; D012307:Risk Factors; D012720:Severity of Illness Index; D016896:Treatment Outcome
chemical_list: D000900:Anti-Bacterial Agents