The development of a screening method for abnormal illness behaviour

The 62-item Illness Behaviour Questionnaire (IBQ) was administered to 100 Pain Clinic patients and 78 General Practice patients in Seattle, Washington; and to 100 Pain Clinic patients and 155 General Practice patients in Adelaide, South Australia. A discriminant function which included scores on Scale 2 (disease conviction), Scale 3 (somatic focusing), Scale 6 (denial) and Scale 7 (irritability) was derived from the scores of the Seattle populations. When this function was applied to the Adelaide populations, the IBQ was found to have a sensitivity of 97%, specificity of 73.55% and hits-positive rate of 0.70. It appears, therefore, that the IBQ may be successfully utilized as a screening instrument in General Practice populations to identify patients manifesting abnormal illness behaviour.