. 2022 Jul 18;10:938113. doi: 10.3389/fpubh.2022.938113

Table 2.

Formulas.

Measure	Formula
Sensitivity	$\frac{T P}{P} = \frac{T P}{T P + F N}$
Specificity	$\frac{T N}{N} = \frac{T N}{T N + F P}$
Accuracy	$\frac{T P + T N}{P + N} = \frac{T P + T N}{T P + T N + F P + F N}$
PPV	$\frac{T P}{T P + F P}$
NPV	$\frac{T N}{T N + F N}$
SE	$\frac{(U p p e r L i m i t - L o w e r L i m i t)}{3.92}$
95% Confidence interval	bestestimate +/− (1.96) * (SE)

P, condition positive; N, condition negative; FN, false negative; FP, false positive; TN, true negative and TP, true positive; PPV, positive predictive value; NPV, negative predictive value; Upper limit, upper limit of confidence interval; Lower limit, lower limit of confidence interval; SE, standard error.