Clinical benefit of a diagnostic score for appendicitis -: Results of a prospective interventional study

Hypothesis: Clinical use of a diagnostic score improves decision making in acute appendicitis. Design: A before-and-after trial comparing a group of patients undergoing standard diagnostic workup with no additional diagnostic support (phase l)with a group of patients undergoing additional diagnostic support with a score (phase 2). Setting: Eight departments of surgery in Germany and Austria. Patients: Eight hundred seventy patients with acute abdominal gain in phase 1 (October 1, 1994, to April 30, 1995) and 614 patients in phase 2 (February 1, 1995, to August 15,1995). Interventions: Structured and standardized history and clinical investigation in all patients with computer-based documentation; introduction of the diagnostic score after phase 1 and computer-supported use of the score in phase 2. Results: The 2 groups were comparable with respect to signs, symptoms, and investigations related to acute appendicitis. Diagnostic performance of the final examiner decreased with the score (specificity, 86% vs 78%; positive predictive value, 67% vs 50%; and accuracy, 88% vs 81%). There were no differences in the rates of perforated appendix, appendectomy with normal findings, and complications; however, the delayed appendectomy rate (2% vs 8%) and the delayed discharge rate (11% vs 22%) were significantly lower with diagnostic support by the score (P = .02). Conclusions: Integration of a score into the diagnostic process may have unforeseen clinical effects. The tested score cannot be recommended as a standard tool for diagnostic decision making in acute appendicitis.