The factor structure of the revised Illness Perception Questionnaire in a population of oesophageal cancer survivors

Abstract

Objectives: To determine whether the proposed seven-factor structure of the Illness Perception Questionnaire—Revised (Timeline Acute/Chronic, Timeline Cyclical, Consequences, Personal Control, Treatment Control, Illness Coherence and Emotional Representations) is appropriate among a population of oesophageal cancer survivors.

Methods: Everyone registered with the Oesophageal Patients' Association in the UK (n = 2185) was mailed a questionnaire booklet, which included the Illness Perception Questionnaire—Revised. Responses from 587 oesophageal cancer survivors (27%) were subjected to a confirmatory factor analysis.

Results: The proposed seven-factor structure provided a reasonable fit of the data. Modification indices suggested that a significantly better fit could be provided if one of the items on the Timeline Acute/Chronic factor loaded on the Treatment Control factor and an error covariance was added between two other items on the Timeline Acute/Chronic factor.

Conclusions: The model fit for the seven-factor structure proposed by Moss-Morris et al. (Psychol Health 2002;17:1–16) was found to be adequate in our study. However, the structure of the timeline acute/chronic factor needs to be considered, particularly when the IPQ-R is to be used among older people with a potentially life-threatening illness or those receiving palliative care.