Alvarado Score for Acute Appendicitis
Patients with suspected acute appendicitis (typically with right lower quadrant pain).
More accurate at extremes than for equivocal scores, so it is unclear whether Alvarado scoring is better than gestalt.
Symptoms may overlap with other diseases; i.e., higher scores are found in patients with non-appendiceal inflammatory conditions, such as diverticulitis or acute pelvic inflammatory disease. It is important to consider the whole clinical picture in making the diagnosis of appendicitis.
Note that several modifications of the score exist, which may be appropriate in specific settings such as pregnant patients, children, and low-resource settings (without lab availability), but the original Alvarado Score remains the best studied and validated in a general population.
Acute appendicitis is the most common surgical emergency in the US. Diagnostic accuracy is increased with greater usage of CT scanning; however, CT confers risks and disadvantages such as cost, radiation exposure, and contrast-related complications. The Alvarado Score is a well-established and widely-used clinical decision tool that may help reduce CT usage.
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Cutoffs differ by study, but one validated stratification assigns the highest risk to scores ≥9 in males or ≥10 in females and lowest risk to scores ≤1 in males or ≤2 in females (Coleman 2018).
In patients who are high risk, consider treatment without CT imaging, and in patients who are low risk, consider alternative diagnoses.
Addition of assigned points.
Facts & Figures
As the Alvarado Score is numerical, it has been evaluated for ruling in and ruling out appendicitis.
Studies ruling out appendicitis (using Alvarado <3-4) have a sensitivity of 96%;
Studies ruling in appendicitis (using Alvarado >6-7) have a sensitivity of 58-88%, depending on the study and score cutoffs used.
The 2007 McKay study recommends CT scan for Alvarado 4-6, surgical consultation for Alvarado ≥7, and for Alvarado ≤3, no CT for diagnosing appendicitis, as appendicitis is unlikely.
The Alvarado Score was initially described in 1986 by Dr. Alfredo Alvarado in a retrospective single center study in Philadelphia. In 305 patients aged 4-80 years, eight predictive factors were identified to stratify risk of acute appendicitis. Increasing scores were found to correlate with increasing risk for appendicitis (as determined by final surgical pathology).
In 2007, McKay and colleagues studied a retrospective cohort of 150 patients (age ≥7 years) presenting with abdominal pain, with the aim of stratifying risk specifically for CT scan usage for diagnosis. They found 35.6% sensitivity for appendicitis based on equivocal Alvarado scores (defined as 4-6) compared with 90.4% sensitivity of CT scan in this group, and concluded that patients with equivocal scores would benefit from CT.
Similarly, Coleman et al (2018) conducted a retrospective review in which the Alvarado Score was applied to a cohort of 492 patients (median age 33 years), and found that 20% of patients were in either the high risk group (defined as ≥9 in males and ≥10 in females) or the low risk group (males ≤1, females ≤2), and cumulatively spent over 170 hours awaiting CT that was ultimately unnecessary. They found that scores of 0 or 1 had 0% incidence of acute appendicitis, and that 100% of males with scores 9-10 and 100% of females with score 10 had acute appendicitis confirmed on surgical pathology.
Pogorelić et al (2015) prospectively studied 311 pediatric patients and applied both the Alvarado score and Pediatric Appendicitis Score (Samuel 2002). Receiver operating characteristic analysis showed similar accuracy between the scores, with AUROC of 0.74 (95% confidence interval 0.662–0.818) for the Alvarado Score and 0.73 (95% CI 0.649–0.811) for the Pediatric Appendicitis Score. The authors concluded that the gestalt of a pediatric surgeon is higher than either scoring system, but the scores may be useful in emergency settings.
Original/Primary ReferenceAlvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986 May;15(5):557-64. PMID: 3963537.
ValidationMcKay R, Shepherd J. The use of the clinical scoring system by Alvarado in the decision to perform computed tomography for acute appendicitis in the ED. Am J Emerg Med. 2007 Jun;25(5):489-93. PMID: 17543650.Pogorelić Z, Rak S, Mrklić I, Jurić I. Prospective validation of Alvarado score and Pediatric Appendicitis Score for the diagnosis of acute appendicitis in children. Pediatr Emerg Care. 2015;31(3):164-8.Coleman JJ, Carr BW, Rogers T, et al. The Alvarado score should be used to reduce emergency department length of stay and radiation exposure in select patients with abdominal pain. J Trauma Acute Care Surg. 2018;84(6):946-950.
Other ReferencesKalan M, Talbot D, Cunliffe WJ, Rich AJ. Evaluation of the modified Alvarado score in the diagnosis of acute appendicitis: a prospective study. Ann R Coll Surg Engl. 1994;76(6):418-9.Samuel M. Pediatric appendicitis score. J Pediatr Surg. 2002;37:872–881.Ohle R, O'Reilly F, O'Brien KK, Fahey T, Dimitrov BD. The Alvarado score for predicting acute appendicitis: a systematic review. BMC Med. 2011;9:139.
About the Creator
Alfredo Alvarado, MD, is a retired general surgeon, formerly at Plantation General Hospital in Florida. He previously held staff positions at Florida Medical Center and Westside Regional Hospital. Dr. Alvarado completed medical training at the National University of Colombia and residencies in general and thoracic surgery.
To view Dr. Alfredo Alvarado's publications, visit PubMed
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