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)