I need assistance with  a research paper and critique an article

Was the diagnostic test evaluated in a Representative spectrum of patients (like those in whom it would be used in practice)?

What is best?

Where do I find the information?

It is ideal if the diagnostic test is applied to the full spectrum of patients - those with mild, severe, early and late cases of the target disorder. It is also best if the patients are randomly selected or consecutive admissions so that selection bias is minimized.

The Methods section should tell you how patients were enrolled and whether they were randomly selected or consecutive admissions. It should also tell you where patients came from and whether they are likely to be representative of the patients in whom the test is to be used.

This paper: Yes ☐ No ☐ Unclear ☐

Comment:

Was the reference standard ascertained regardless of the index test result?

What is best?

Where do I find the information?

Ideally both the index test and the reference standard should be carried out on all patients in the study. In some situations where the reference standard is invasive or expensive there may be reservations about subjecting patients with a negative index test result (and thus a low probability of disease) to the reference standard. An alternative reference standard is to follow-up people for an appropriate period of time (dependent on disease in question) to see if they are truly negative.

The Methods section should indicate whether or not the reference standard was applied to all patients or if an alternative reference standard (e.g., follow-up) was applied to those who tested negative on the index test.

This paper: Yes ☐ No ☐ Unclear ☐

Comment:

Was there an independent, blind comparison between the index test and an appropriate reference ('gold') standard of diagnosis?

What is best?

Where do I find the information?

There are two issues here. First the reference standard should be appropriate - as close to the 'truth' as possible. Sometimes there may not be a single reference test that is suitable and a combination of tests may be used to indicate the presence of disease.

Second, the reference standard and the index test being assessed should be applied to each patient independently and blindly. Those who interpreted the results of one test should not be aware of the results of the other test.

The Methods section should have a description of the reference standard used and if you are unsure of whether or not this is an appropriate reference standard you may need to do some background searching in the area.

The Methods section should also describe who conducted the two tests and whether each was conducted independently and blinded to the results of the other.

This paper: Yes ☐ No ☐ Unclear ☐

Comment:

Are test characteristics presented?

What is the measure?

What does it mean?

Sensitivity (Sn) = the proportion of people with the condition who have a positive test result.

The sensitivity tells us how well the test identifies people with the condition. A highly sensitive test will not miss many people.

Specificity (Sp) = the proportion of people without the condition who have a negative test result.

The specificity tells us how well the test identifies people without the condition. A highly specific test will not falsely identify many people as having the condition.

Were the methods for performing the test described in sufficient detail to permit replication?

What is best?

Where do I find the information?

The article should have sufficient description of the test to allow its replication and also interpretation of the results.

The Methods section should describe the test in detail.

This paper: Yes ☐ No ☐ Unclear ☐

Comment:

What were the potential and presented threats to validity?

What is best?

Where do I find the information?

The authors should acknowledge areas of limitations. The purpose of the appraisal is to identify threats that the authors don’t identify.

The authors should list limitations in a “limitations” section.

Potential threats – are the ones that you identified throughout your appraisal.

This paper: Yes ☐ No ☐ Unclear ☐

Comment: