EN: Selection bias

[Guest guest]

Please note, I do know the common statistical concept of selection bias, but

it seems to me that it doesn't apply in this context.

The text is a textbook in family medicine, a chapter about doctor-patient

communication. The paragraph runs:

" Symptoms are the patient's description of what he or she perceives to be

abnormal sensations. By definition, they are subjective and not open to

verification by empirical methods. There is no objective test by which we

can verify that a patient is actually feeling pain. This is not to say,

however, that we cannot apply rigorous methods to understanding the meaning

of a patient's symptoms. The methods are those of attentive listening,

clarification of meaning through dialogue, and avoidance of selection bias. "

So, there is no trial or study going on, no patient groups to compare, only

this single patient, whose symptoms the physician is to interprete. What

would you then say that the author mean by " selection bias " ?

Many thanks in advance?

Folke A. Nettelblad