What Are the Most Clinically Useful Cutoffs for the Alvarado and Pediatric Appendicitis Scores? A Systematic Review

For children with a pretest probability of acute appendicitis of 60% or less, an Alvarado score below 4 rules out the diagnosis; this is also true for a score less than 5 if the pretest probability is up to approximately 40%. In adults with a pretest probability greater than or equal to 60%, an Alvarado score of 8 or higher rules in the diagnosis, whereas one of 9 or higher rules in the diagnosis at pretest probabilities greater than or equal to 40%. The Pediatric Appendicitis Score did not identify clinically useful low- or high-risk groups at typical pretest probabilities.