Worksheet for evaluating an article about diagnosis

Assessing relevance

The test in question is feasible in my community and practice:  o Yes o No

Patients are similar to those I see in my practice, and included patients with varying severity of disease as well as other patients with similar presenting symptoms but no disease:   o Yes o No

Assessing validity

A reasonable reference standard was used: o Yes o No

Results of the reference standard were not known to the examiner: o Yes o No

Data were collected prospectively:  o Yes o No

All patients received both clinical examination and reference standard: o Yes o No

If no, were patients who didn’t get the reference standard followed up closely enough and long enough to convince you that they are free of disease?    o Yes o No

Usefulness

Fill in the 2 x 2 table for the diagnostic test:

 

Disease

No Disease


_______  positive

a

b


______  negative

c

d


sensitivity = a / (a + c) = ______

specificity = d / (b+d) = ______

PV+ = a / (a + b) = _________

PV- = d / (c + d) = _________

LR+ = sens / (1-spec) = ______

LR- = (1-sens) / spec  = ______

 

Disease

No Disease


_______  positive

a

b


______  negative

c

d


sensitivity = a / (a + c) = ______

specificity = d / (b+d) = ______

PV+ = a / (a + b) = _________

PV- = d / (c + d) = _________

LR+ = sens / (1-spec) = ______

LR- = (1-sens) / spec = ______