Diagnostic value of disease history, clinical presentation, and inflammatory parameters of appendicitis

The clinical diagnosis of appendicitis needs to be improved, as up to 40% o f explorations for suspected appendicitis are unnecessary. The use of body temperature and laboratory examinations as diagnostic aids in the managemen t of these patients is controversial. The diagnostic power of these variabl es compared to that of the disease history and clinical findings is not wel l studied. In this study we prospectively assessed and compared the diagnos tic value of 21 elements of the history, clinical findings, body temperatur e, and laboratory examinations in 496 patients with suspected appendicitis. The diagnostic value of each variable was compared from the area under the receiver operating characteristic (ROC) curve and the likelihood ratios (L R). Logistic regression was used to analyze the diagnostic value of a combi nation of variables and to analyze independent relations. No single variabl e had sufficiently high discriminating or predicting power to be used as a true diagnostic test. The inflammatory variables (temperature, leukocyte an d differential white blood cell (WBC) counts, C-reactive protein) had discr iminating and predicting powers similar to those of the clinical findings ( direct and rebound abdominal tenderness and guarding). Anorexia, nausea, an d right-sided rectal tenderness had no diagnostic value. The leukocyte and differential WBC counts, C-reactive protein, rebound tenderness, guarding, and gender were independent predictors of appendicitis with a combined ROC area of 0.93 for appendicitis. This showed that inflammatory variables cont ain important diagnostic information, especially with advanced appendicitis . They should therefore always be included in the diagnostic workup in pati ents with suspected appendicitis.