This calculator is for educational use.
It is believed accurate but no responsibility for accuracy of the results is accepted by the authors.
Bayes-Theorem :
proportion values in absolute numbers (1.0 = 100%)
INPUT QUALITY (IQ)
2x2 CT CALCULATION TABLE
OUTCOME QUALITY (OQ)
pretest probability of disease
(POD, PTP) , prevalence (PV)
odds , hazard
(TP+fn) : (fp+TN)
(TP+fn)/(TP+fn+fp+TN)
rate , risk
Bayes constellation
unsharpness of a cut
TEST
DISEASE +
DISEASE −
test pos
(+)
TP
fp
test neg
(−)
fn
TN
posttest probability of disease
PDV resp. POD
rate , risk
odds , hazard
PPV=TP/(TP+fp)
pPOD=TP:fp
=1-
NPV=TN/(fn+TN)
nPOD=fn:TN
FUNCTION-
QUALITY (FQ)
of the TEST
SEnsitivity
TP/(TP+fn)
SPecificity
TN/(fp+TN)
BAYES kernel
likelihood
ratio
(LR)
pLR=SE/[1−SP]
nLR=[1−SE]/SP
Legend:
TP = true positive testresults , fp = false positive , fn = false negative , TN = true negative testresults . PDV = predictive value , PPV = pos predictive value , NPV = neg predictive value , POD = probability of disease , PTP = pretest probability of disease . Prefix : p = "after positive" , n = "after negative testresult" . nPOD = 1−NPV .
equation for
transformation
of proportions
odds vs risk
o = r/(1−r)
r = o/(o+1)
SELECT 95% CI
Wilson
, Newcombe
SELECT
calculation option
2x2 contingency table
power, factor
PV, FQ
→
PPV, NPV ?
PPV, NPV, FQ
→
PV ?
PV, PPV, NPV
→
FQ ?
Fagan calculations
risk-odds-transform
The ultimative
Bayes calculator for an evidence based diagnosis and prognosis
calculating the Bayes-Theorem in all directions. A Fagan calculator (replacing the FAGAN-Nomogram) is integrated. The input quality (IQ, prevalence PV, pretest probability of disease POD sive PTP), the outcome quality (OQ, predictive value PPV and NPV, posttest POD), the function quality (FQ, sensitivity, specifity) and the Bayes kernel (LR, likelihood ratio, pLR, nLR) are computed according the inputs of free chooseable determinative variables. The 95%-confidence intervals are listed in a separate table. Also power calculations are possible.
The program is a freeware and available to the interested user. It is not charged by a copyright. Because of its integrated Javascript the program is also working offline. Be aware that the internet security manager of your browser is not suppressing JavaScript .
Dr. med. Franz Ackermann , FMH Innere Medizin
Dr. med. M. Romanens , Kardiologie FMH , CH-4600 Olten
BayesCompact_e.html , Version 1.1 english, November 11
^{th}
2006
Special Edition Task Force of Vascular Risk Prediction