Factor analytic investigation of the Illness Attitudes Scale in a chronic pain sample

The Illness Attitudes Scale (IAS) is a self-report instrument comprising nine subscales designed to assess fears, beliefs and attitudes associated with hypochondriasis and abnormal illness behaviour [Kellner (1986). Somatization and hypochondriasis. New York: Praeger.]. The purpose of the present study was to explore the factor structure of the IAS in a chronic pain sample as a preliminary step toward determining the use of this measure in this sample. Hypochondriacal tendencies have been postulated to play a role in maintaining and exacerbating responses to chronic pain and, therefore, appropriate measurement in this sample is important. In the present study, consecutive chronic pain patients presenting to a pain treatment program (N = 198) were administered the IAS. Principal component analysis with oblique (Oblimin) rotation identified that five factors best explain the measure in this population. These factors were (1) fear of illness, (2) effects of symptoms, (3) health habits, (4) disease phobia and conviction and (5) fear of death. The factor structure overlapped to some degree with the scoring of the IAS proposed by Kellner (1986), as well as with the factor structure identified in a non-clinical sample [Ferguson, E. & Daniel, E. (1995). The Illness Attitudes Scale (IAS): a psychometric evaluation on a non-clinical population. Personality and Individual Differences, 18, 463-469.]. There were enough discrepancies, however, to suggest an alternative method for scoring the IAS with chronic pain patients. Implications for the use of the measure with chronic pain patients, as well as future research directions for exploring the utility of this measure with chronic pain patients, are discussed.