Disease X is diagnosed by using a PCR on a nasopharyngeal swab which has a sensitivity of 90%. However disease X can also be diagnosed by using a throat swab but with a lower sensitivity of 70%.

Do you accept the throat swab for testing?

Many laboratories do…

However by doing so I think we are accepting second best, regardless of how the result is reported, or what disclaimers are added.

By rejecting such a throat swab and asking for a nasopharyngeal swab (or whatever the optimal sample might be), the requestor/s quickly learns what swabs should be taken. It does not take long for the laboratory to start getting the correct samples consistently, and as a consequence, give out the best results.

Regardless of which microbiology discipline you are talking about, when you accept samples that are second best, you can be sure that you will continue to receive them. The difference in sensitivity/specificity is often not appreciated by the requestor, even if it is documented on the report.

Of course you might get a grumpy phone call from an annoyed clinician asking why their patient’s swab was not processed when it was sent to the laboratory, but the ensuing empathy and explanation that is required are all part and parcel of the job. (and water off a duck’s back for me!)

If you want to have a really high quality laboratory, producing really high quality results, then you need to be really strict with what is acceptable for testing…

Tough love.

Michael