A comparison of alternative indices of abnormal illness behaviour derived from the Illness Behaviour Questionnaire

Abstract

Patients with abnormal illness behaviour (AIB) display behaviour disproportionate to the medical assessment of their objective pathology. The Illness Behaviour Questionnaire (IBQ) quantifies AIB using 11 summary scores. The current paper uses data from 218 stroke rehabilitation patients to review proposals for either shorter versions of the IBQ or the categorical classification of AIB. The aims were to determine the overlap among scoring alternatives, and to examine aspects of construct validity. No single index reflected all original IBQ scales. Several AIB indices were significantly associated with both depression and generalized neurotic dysfunction, although none more so than the original IBQ scales. There were few significant relationships between AIB indices and functional disability. Internal consistency was relatively low for applicable indices. It was concluded that the data presented do not permit unequivocal recommendation among the alternative AIB indices reviewed. In the absence of unambiguous evidence to the contrary, the comprehensive profile provided by the original IBQ scales may remain the best option for the evaluation of AIB.