Diagnosing acute appendicitis (aA) remains difficult. This study evaluated the utility of ultrasonography (US) compared to clinical decision-making alone and scoring systems to establish the indication for laparotomy in patients in whom aA was suspected. The prospectively documented data of 2209 patients admitted for suspicion of aA, who underwent US by one of 12 surgeons, formed a database in which the diagnostic and procedural performance of clinical decision-making, US, two scoring systems (Ohmann and Eskelinen scores), and clinical algorithms taking account of clinical and either US findings or score results, were retrospectively evaluated. The results of either modality were correlated with final diagnoses obtained by laparotomy in 696 patients, of whom 540 had aA (prevalence 24.45%) and follow-up data in the remainder. US had the highest specificity (97%, compared to 93% for the Ohmann and Eskelinen scores and 94% for the clinical evaluation and algorithms) and lowest overall rate of false-positive findings (negative laparotomy rate 7.6%). The scores were accurate in refuting the diagnosis of aA but otherwise not superior to US. The best overall diagnostic and procedural results were obtained with the algorithms that combined the results of either US or the Ohmann score with clinical evaluation, which produced the most favorable numbers of negative laparotomies, potential perforations, and missed cases of aA. US is the diagnostic standard of reference for patients with a possible diagnosis of aA. It yields diagnostic results superior to those of scoring systems and provisional clinical evaluation. However, the benefits of US by ultrasonographically trained surgeons are only fully appreciated within the context of clinical algorithms. The joint evaluation of score results and clinical evaluation may deliver information of similar accuracy.

A diagnostic scoring system, recently published by Ohmann et al. in this journal, was validated by analyzing the clinicopathological data of a consecutive series of 2,359 patients, admitted for suspicion of acute appendicitis. The results of the scoring system were compared to the results of clinical evaluation by junior (provisional) and senior surgeons (final clinical diagnosis). To assess the diagnostic ability of the score, the accuracy and positive predictive value were defined as the major diagnostic performance parameters; the rate of theoretical negative laparotomies and that of diagnostic errors served as the major procedural performance parameters. Of 2,359 patients admitted for suspected acute appendicitis, 662 were proven to have acute appendicitis by histology, for a prevalence of 28%. The overall sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the provisional clinical diagnosis were 0.50, 0.94, 0.77, 0.83, and 0.82; 0.93, for the score 0.63, 0.93, 0.77, 0.86 and 0.84, and for the final clinical diagnosis 0.90, 0.94, 0.85, 0.96, and 0.93, respectively. Of the main diagnostic performance parameter, the accuracy of the score was significantly better than that of provisional clinical diagnosis (P < 0.05, chi 2 test). The score yielded a rate of negative appendecomies and laparotomies of 14.3 and 12.3%. With respect to the rate of overlooked cases of acute apendicitis, the score demonstrated a superior performance, with only 6 cases missed (0.9%). However, the number of patients with acute appendicitis, including those with perforated disease, who were not identified by the score, was almost four times that of the final clinical diagnosis (245 vs 63). With regard to the main procedural performance parameter, the score resulted in a significantly smaller number of diagnostic errors than the provisional clinical investigator (P < 0.05, chi 2 test). The results of this study indicate that the diagnostic scoring system might be helpful when experienced investigators or additional diagnostic modalities such as ultrasonography are not available. It may therefore be of value in the preclinical evaluation of patients with suspected acute appendicitis and may be instrumental as a quality control tool and in clinical guidelines.