Outils de recherche › Diagnostic 2×2

Diagnostic Test 2×2 Table Calculator

Saisissez les vrais positifs, faux positifs, faux négatifs et vrais négatifs du tableau 2×2 pour calculer sensibilité, spécificité, valeurs prédictives positive/négative, exactitude, rapports de vraisemblance, le rapport de cotes diagnostique et l'indice de Youden ; les proportions incluent des IC Wilson à 95 %.

① Fill in the 2×2 table

	Gold standard +	Gold standard −
Test +
Test −

Mode d'emploi et méthodologie

What do the 2×2 metrics mean?

Sensitivity = TP/(TP+FN), reflecting few missed cases; specificity = TN/(TN+FP), reflecting few false alarms; PPV is the proportion of test-positives who are truly diseased; NPV is the proportion of test-negatives who are truly non-diseased.

Pourquoi do predictive values change?

PPV and NPV depend on the population prevalence: for the same test, PPV is higher in a high-prevalence population and lower in a low-prevalence one. When citing literature predictive values, check whether their prevalence matches your population; likelihood ratios are unaffected by prevalence and more stable.

Comment read likelihood ratios?

The larger the positive LR (+LR), the more a positive test indicates disease; above 10 is usually strong diagnostic value. The smaller the negative LR (−LR), the better a negative test rules disease out; below 0.1 is strong. The diagnostic odds ratio (DOR) summarizes overall discrimination.

Pourquoi the Wilson method for CIs?

For proportions, the traditional Wald interval is distorted at small samples or when the proportion is near 0/1. The Wilson method is more robust at small samples and never goes out of bounds, so sensitivity, specificity and other proportions here use Wilson 95% CIs.