2. Appraising the relevance of results

2.3 The eight steps

6. Is there any bias or any factor that can lead to confusion ?

A bias is a systematic error that regularly produces higher or lower estimated values than the actual value of the parameters being studied. A bias can occur, for example, at the point when patients are being selected, or when study parameters are being measured.

A factor that can lead to a confusion is a factor that modifies the effects of the factor being studied on the basis of judgment criteria, due to an association between the factor and the criterion.

Have they been considered and taken into account?If not, then the validity of the study may be questioned.