Introduction: Diagnosis of apendicitis is difficult; however several clinical scales have been developed that attempt to improve diagnostic accuracy.
Objective: The operational characteristics of Alvarado and Fenyö scales were defined in patients with abdominal pain suggestive of appendicitis and were compare with clinical and pathological diagnoses.
Material and methods: A prospective trial assessed the diagnostic tests. Sign, symptoms, and laboratory tests were included in scales selected. Surgeon decision was maintained independent from the results of the scales. Sensitivity, specificity, positive and negative predictive value and positive and negative likelihood ratio for each scale was compared with the surgeon evaluation.
Results: The sample included 374 patients with approximately equal sexes. Of these 269 patients underwent surgery. Howeve, 16.9% of the male and 31.4% of female patients did not have appendicitis. For men, a diagnosis made by the surgeon had better sensitivity than scales (86.2% vs. 73% for Alvarado and 67.2% for Fenyö) without significant differences in specificity. For women, surgeon and Alvarado scale diagnoses were similar, and better than Fenyö scale (77.1% vs. 79.5% for Alvarado and 47% for Fenyö), but specificity was higher for Fenyö scale (92.9% vs. 71.4% for Alvarado and 75.9% for surgeon). Accuracy in diagnosis of appendicitis increases with a higher Alvarado score.
Conclusion: For men with abdominal pain on right lower quadrant, surgeon diagnosis is more accurate than scales. For women, Fenyö scale offers a better sensitivity. Alvarado score can facilitate decision-making in patients with these abdominal symptoms.