Journal Articles

Published Research

The following is a summary of journal publications by Associate Professor Knowles. Click on the references below for further details.

Journal Articles


Knowles, S. R., Wilson, J.L., Connell, W.R., Kamm. M. A. (2011). A preliminary examination of the relations between disease activity, illness perceptions, coping strategies and psychological morbidity in Crohn's disease guided by the common sense model of illness. Inflammatory Bowel Diseases, 17(12), 2551-2557.

Background: An individual’s psychological adjustment to illness is influenced by disease severity, illness perceptions, and coping strategies. A more precise understanding of the contribution of each of these factors to a patient’s well-being may influence the kind of psychological support required by patients. This study therefore aimed to characterize the contributors to psychological well-being in patients with Crohn’s disease (CD). The design was a cross-sectional questionnaire-based study.

Methods: Ninety-six CD patients (34 males, 62 females, mean age 38 years) attending a tertiary hospital inflammatory bowel disease outpatient clinic were studied. Disease severity was evaluated according to the Crohn’s Disease Activity Index (CDAI), coping styles assessed with the Carver Brief COPE scale, illness perceptions explored with the Brief Illness Perceptions Questionnaire (BIPQ), and anxiety and depression measured using the Hospital Anxiety and Depression Scale (HADS).

Results: Combining the questionnaire data using structural equation modeling resulted in a final model with an excellent fit (χ(2) (7) = 10.42, P = 0.17, χ(2) /N = 1.49, root mean square error of approximation (RMSEA) < 0.07, comparative fit index (CFI) > 0.97, Goodness-of-fit index (GFI) > 0.97). Disease activity had a significant direct influence on illness perceptions (β = 51, P < 0.001). In turn, illness perceptions had a significant direct influence on depression and anxiety (β = 41, P < 0.001, β = 0.40, P < 0.001, respectively). Use of emotional coping strategies was associated significantly (P < 0.001) with the presence of anxiety and depression.

Conclusions: There is an interrelationship between disease activity, illness perceptions, coping strategies, and depression and anxiety. These aspects of psychological processing provide a framework and direction for the psychological support that patients with CD require.