Improving the medical scale predictability by the pairwise comparisons method: evidence from a clinical data study.

In the clinical practice of psychiatry, presence or absence of particular symptoms is based on the subjective interpretation, by the clinician, of mental and behavioural descriptions offered by the patient. However, this subjectivity that characterizes the diagnostic decision making process may limit the reliability of diagnosis. In this current study, the pairwise comparisons (PC) method is used to investigate whether the psychometric properties of a medical screening questionnaire can be improved. The pilot data described herein did indeed demonstrate that modest improvements in diagnostic accuracy could be achieved using PC, and provides early evidence that the inconsistency produced by subjective clinical ratings can be reduced using this method, thus providing impetus for further investigation.