Working Table for the Reader's Use
For accuracy
Sensitivity = a/(a + c); SnNout: when sensitivity is high, a negative test result rules out the target disorder
Sensitivity = d/(b + d); SpPin: when specificity is high, a positive test result rules in the target disorder.
Positive predictive value or posttest probability of having the target disorder among patients with positive test results, a/(a + b).
Source:
A Primer
on the
Precision
of theamong
Clinicalpatients
Examination,
The Rational
Clinicald/(c
Examination:
Evidence-Based
Negative predictive value or
posttest
probability
of not
havingand
the Accuracy
target disorder
with negative
test results,
+ d). Posttest
probability of
Clinical
having the target disorder for patients
withDiagnosis
negative test results, c/(c + d).
Citation:
D. The Rational
Clinical
Evidence-Based Clinical Diagnosis; 2016 Available at:
Prevalence or pretest probability
of Simel
havingDL,
theRennie
target disorder,
(a + c)/(a
+ b + Examination:
c + d).
http://mhmedical.com/
Accessed:
July
31,
2017
Sensitivity/(1 – specificity) = likelihood ratio (LR) (of having the target disorder) for a positive test result = (a/[a + c])/(b/[b + d]).
Copyright © 2017 American Medical Association. All rights reserved
(1 – sensitivity)/specificity = LR (of having the target disorder) for a negative test result = (c/[a + c])/(d/[b + d]).
Posttest probability of the target disorder (expressed as odds) = pretest probability of the target disorder (expressed as odds) × LR for the test result.