Illness denial questionnaire for patients and caregivers

Interest in assessing denial is still present, despite the criticisms concerning its definition and measurement. We tried to develop a questionnaire (Illness Denial Questionnaire, IDQ) assessing patients' and caregivers' denial in relation to their illness/disturbance.

After a preliminary study, a final version of 24 dichotomous items (true/false) was selected. We hypothesized a theoretical model with three dimensions: denial of negative emotions, resistance to change, and conscious avoidance, the first two composing the actual Denial and the last representing an independent component of the illness denial behavior. The IDQ was administered to 400 subjects (219 patients and 181 caregivers) together with the Anxiety-Depression Questionnaire - Reduced form (AD-R), in order to assess concurrent validity. Confirmatory factor analysis (CFA), internal consistency indices (Cronbach's α and McDonald's ω), and test-retest analysis were performed.

CFA and internal consistency indices (Cronbach's α: 0.87-0.96) indicated a clear and meaningful three-factor structure of IDQ, for both patients and caregivers. Further analyses showed good concurrent validity, with Denial and its subscale negatively associated with anxiety and depression and avoidance positively associated with anxiety and depression. The IDQ also showed a good stability (r from 0.71 to 0.87).

The IDQ demonstrated good psychometric properties. Denial of negative emotions and resistance to change seem to contribute to a real expression of denial, and conscious avoidance seems to constitute a further step in the process of cognitive-affective elaboration of the illness.