Alvarado score
Probability of acute appendicitis across eight findings, maximum 10 points. Mnemonic MANTRELS.
Updated · Methodology
About this calculator
The score gathers three symptoms, three examination findings and two laboratory values. Two of them carry 2 points each: right lower quadrant tenderness and leukocytosis above 10 ×10⁹/L; the rest carry one. Interpretation: 1-4 appendicitis unlikely, 5-6 compatible, 7-8 probable, 9-10 very probable. The real usefulness of the score sits at the low end. At 4 points or below the negative predictive value is high, which argues against immediate surgery and for observation. The high end performs worse: a high score does not replace imaging, because the positive predictive value in an unselected population is modest. On the groups where the score loses accuracy: in women of childbearing age, ectopic pregnancy, ovarian cyst rupture and pelvic inflammatory disease produce the same set of findings. In children and older patients the presentation is blunted, fever is often absent, and a low score does not rule appendicitis out. The score was derived in 1986 in a cohort predating widespread CT, and current emergency protocols use it as one input to an algorithm rather than as a deciding criterion.
Source
Formula version: alvarado-1986-v1
Related
Calculators
- Ranson Criteria (acute pancreatitis severity)Acute pancreatitis severity scored at admission and 48 hours later. A score ≥ 3 indicates moderate-to-severe disease.
- BISAP calculator: bedside index for acute pancreatitis severityAssess acute pancreatitis severity with the 5 BISAP criteria: BUN, mental status, SIRS, age, pleural effusion.