World J. Surg. 23, 133–140, 1999 WORLD Journal of SURGERY © 1999 by the Socie ´te ´ Internationale de Chirurgie Diagnostic Value of Disease History, Clinical Presentation, and Inflammatory Parameters of Appendicitis Roland E. Andersson, M.D., Ph.D., 1 Anders P. Hugander, M.D., Ph.D., 1 Sam H. Ghazi, M.D., 2 Hans Ravn, M.D., 3 S. Karsten Offenbartl, M.D., Ph.D., 3 Per Olof Nystro ¨m, M.D., Ph.D., 4 Gunnar P. Olaison, M.D., Ph.D. 4 1 Department of Surgery, Ryhov Hospital, S-551 85 Jo ¨nko ¨ping, Sweden 2 Department of Clinical Pathology, Ryhov Hospital, S-551 85 Jo ¨nko ¨ping, Sweden 3 Department of Surgery, Highlands Hospital, S-575 81 Eksjo ¨, Sweden 4 Department of Surgery, University Hospital, S-581 85 Linko ¨ping, Sweden Abstract. The clinical diagnosis of appendicitis needs to be improved, as up to 40% of explorations for suspected appendicitis are unnecessary. The use of body temperature and laboratory examinations as diagnostic aids in the management of these patients is controversial. The diagnostic power of these variables compared to that of the disease history and clinical findings is not well studied. In this study we prospectively assessed and compared the diagnostic value of 21 elements of the history, clinical findings, body temperature, and laboratory examinations in 496 patients with suspected appendicitis. The diagnostic value of each vari- able was compared from the area under the receiver operating charac- teristic (ROC) curve and the likelihood ratios (LR). Logistic regression was used to analyze the diagnostic value of a combination of variables and to analyze independent relations. No single variable had sufficiently high discriminating or predicting power to be used as a true diagnostic test. The inflammatory variables (temperature, leukocyte and differential white blood cell (WBC) counts, C-reactive protein) had discriminating and predicting powers similar to those of the clinical findings (direct and rebound abdominal tenderness and guarding). Anorexia, nausea, and right-sided rectal tenderness had no diagnostic value. The leukocyte and differential WBC counts, C-reactive protein, rebound tenderness, guard- ing, and gender were independent predictors of appendicitis with a combined ROC area of 0.93 for appendicitis. This showed that inflam- matory variables contain important diagnostic information, especially with advanced appendicitis. They should therefore always be included in the diagnostic workup in patients with suspected appendicitis. Patients with suspected appendicitis are mainly managed on the basis of their disease history and the physical examination; the value of laboratory examinations is controversial. The clinical diagnosis is difficult, and management errors are frequent, with rates of negative explorations reaching 20% to 40% [1, 2]. The diagnosis of appendicitis has mainly been studied in patients operated on because of suspected appendicitis. A few large studies have included all patients with abdominal pain, even those with no clinical suspicion of appendicitis. The importance of variables such as the presence of right lower quadrant pain or previous surgery is different in these populations, as the diagnostic value is influenced by the prevalence and spectrum of disease in the study population [3]. The pertinent study population for assessing the importance of diagnostic variables in the management of these cases is the unselected population of patients with a clinical suspicion of appendicitis. We identified 13 studies on such populations that included at least 50 patients with proved appendicitis [4 –18]. Only three studies had included more than 100 patients with appendi- citis. Knowledge of the diagnostic value of particular elements of the disease history, clinical examination, and laboratory investi- gations is therefore limited [19, 20]. A correct diagnosis is most urgent in patients with advanced appendicitis, as the morbidity and mortality is highest in these cases. The clinical diagnosis of advanced appendicitis has been analyzed in a few retrospective studies of operated patients but not in any prospective study of patients with suspected appendi- citis. The aim of the present study was to assess and compare the diagnostic value of elements of the disease history, the clinical findings, and the laboratory examinations in patients admitted because of suspected appendicitis. The diagnostic value of the variables for advanced appendicitis was analyzed separately. Patients and Methods Patients The study is based on 502 patients (281 women, 221 men) who had been admitted for suspected appendicitis to the hospitals in Jo ¨nko ¨ping and Eksjo ¨, Sweden, between October 1992 and De- cember 1993. Patients under 10 years of age were not included. Median age was 21 years (range 10 – 86 years). The study was observational, and no intervention was done in the current management of the patients except for the addition of a formal- ized collection of data. This was done by the staff who usually manage these patients. Appendicitis was found in 194 of 259 operated patients (diag- nostic accuracy 75%) (Table 1). The appendix had perforated in 28 patients (perforation rate 14%). Another 41 patients had histopathologic signs of gangrene, giving a total of 69 patients with Correspondence to: R.E. Andersson, M.D.