Diagnosis IDiagnosis IDr. Brent E. Faught, Ph.D.Dr. Brent E. Faught, Ph.D.
Assistant ProfessorAssistant ProfessorFaculty of Applied Health SciencesFaculty of Applied Health Sciences
Brock UniversityBrock UniversitySt.Catharines, ON, CanadaSt.Catharines, ON, Canada
Guidelines for Diagnostic Guidelines for Diagnostic LiteratureLiterature
Is this test potentially relevant to my practice?Is this test potentially relevant to my practice?
Has the test been compared with a true gold Has the test been compared with a true gold
standard?standard?
Did this validation study include an appropriate Did this validation study include an appropriate
spectrum of subjects?spectrum of subjects?
Guidelines for Diagnostic Guidelines for Diagnostic LiteratureLiterature
Has work-up bias been avoided?Has work-up bias been avoided?
Has expectation bias been avoided?Has expectation bias been avoided?
Was the test shown to be reproducible?Was the test shown to be reproducible?
What are the features of the test as derived What are the features of the test as derived
from this validation study?from this validation study?
Guidelines for Diagnostic Guidelines for Diagnostic LiteratureLiterature
Were confidence intervals given?Were confidence intervals given?
Has a sensible "normal range" been derived?Has a sensible "normal range" been derived?
Has this test been placed in the context of other Has this test been placed in the context of other
potential tests in the diagnostic sequence?potential tests in the diagnostic sequence?
Conditional ProbabilitiesConditional Probabilities
(T (T ++))
(T (T --))
(D (D ++))
TrueTruePositivePositive
(D (D --))
FalseFalseNegativeNegative
TrueTrueNegativeNegative
FalseFalsePositivePositive
Gold StandardGold Standard
ClinicalClinicalTestTest
Interpretation of Diagnostic Interpretation of Diagnostic DataData
(T +)
(T -)
(D +)
AA
(D -)
CC DD
BB P ( P ( T T ++ D D ++ ))
(A + C)(A + C)
OR
__A____A__
Interpretation of Diagnostic Interpretation of Diagnostic DataData
(T +)
(T -)
(D +)
AA
(D -)
CC DD
BB P ( P ( T T -- D D -- ))
(B + D)(B + D)
OR
__D____D__
Interpretation of Diagnostic Interpretation of Diagnostic DataData
(T +)
(T -)
(D +)
AA
(D -)
CC DD
BB P ( P ( T T -- D D ++ ))
(A + C)(A + C)
OR
__C____C__
Interpretation of Diagnostic Interpretation of Diagnostic DataData
(T +)
(T -)
(D +)
AA
(D -)
CC DD
BB P ( P ( T T ++ D D -- ))
(B + D)(B + D)
OR
__B____B__
Interpretation of Diagnostic Interpretation of Diagnostic DataData
(T +)
(T -)
(D +)
AA
(D -)
CC DD
BB P ( P ( D D + + ))
OR
(A + C)(A + C)