The shortcut world of acronyms for critical appraisal was lacking one for diagnostic test accuracy – we have RAMbo for RCTs, FAST for systematic reviews, but what of the poor reader of studies evaluating a new test?
We know the basic idea – patients who are considered to potentially have the diagnosis in question have both the test-under-evaluation and the as-good-as-we, these are assessed without looking at the results from the other one, and that if there are cut-offs these are reproducible.
Wait! That’s it …
We need an Appropriate population – not a mix of barn door and definitely not
It needs to avoid Verification biases – make sure that everyone got both tests, not just those in whom the ‘new’ test was positive, for example
The tests need to be Independent of each other
And don’t believe a single study – with diagnostics we need to see Duplication of results
There we go … AVID