MDCalc Corner: Alvarado Score

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To scan or not to scan?’ That’s the (app-y) question.

Alvarado Score
Signs Right lower quadrant tenderness +2
Elevated temperature (>37.3°C or 99.1°F) +1
Rebound tenderness +1
Symptoms Migration of pain to the right lower quadrant +1
Anorexia +1
Nausea or vomiting +1
Lab Values Leukocytosis > 10,000 +2
Leukocyte left shift +1


Acute appendicitis (AA) is the most common surgical emergency in the US.[1] Diagnostic accuracy is increased with greater usage of CT scanning; however CT confers risks and disadvantages such as cost, exposure to radiation and contrast-related complications. The Alvarado Score is a well-established and widely-used clinical decision tool that may help reduce CT usage.


The Good (Why Use It)

  • Accurate at extremes: Alvarado Score of 0 or 1 had 0% incidence of AA; 100% of males with Alvarado Score 9-10 and 100% of females with score 10 had AA confirmed on surgical pathology.
  • In patients with scores at these high or low extremes (21.5% of patients in one study), has been shown to reduce CT scan usage and ED length of stay.[2]

The Bad (Limitations)

  • Wide range of equivocal scores, so it’s unclear whether Alvarado scoring is better than gestalt.[1]
  • Different studies recommend different cutoffs, so local incidences and practices may affect outcomes.

The Ugly (Misapplications)


  • Higher Alvarado Scores are found in patients with non-appendiceal inflammatory conditions, such as diverticulitis or acute pelvic inflammatory disease.[3]
  • Females with an Alvarado Score of 2 or less still had a 3.57% incidence of AA.2
  • The majority of patients (78.5% who underwent CT for suspected appendicitis in one study[2]) has an equivocal score and therefore cannot avoid imaging.


Retrospective study, single center in Philadelphia, 305 patients aged 4-80 years.[4] Eight predictive factors identified to stratify risk of AA.


A retrospective review studied 492 patients, median age of 33 years, 58.9% white and 36.2% black or African American. In that review, 20% of patients were in either the high (males ≥9, females ≥10) or low (males ≤1, females ≤2) risk group and cumulatively spent over 170 hours awaiting CT that was ultimately unnecessary.[4]


Bottom Line

The Alvarado Score is useful at extremes to reduce CT usage and ED stay, but may not always supersede clinical judgment and has limited usefulness in definitively diagnosing or ruling out AA without CT.


[1] Korner H, Sondenaa K, Soreide JA, Andersen E, Nysted A, Lende TH, et al. Incidence of acute nonperforated and perforated appendicitis: age-specific and sex-specific analysis. World J Surg. 1997;21:313–7.

[2] 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.

[3] Mckay 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;25(5):489-93.

[4] Alvarado A. A practical score for the early diagnosis of acute appendicitis. Ann Emerg Med. 1986;15(5):557-64.


Xiao Chi (Tony) Zhang, MD, MS, is a medical education fellow at Philadelphia University/Thomas Jefferson University.

Ayomide Loye, MD, is an emergency medicine resident at Philadelphia University/Thomas Jefferson University.

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