Objectives: To evaluate the disease-specific and psychological factors that influence quality of life (QOL) in patients with inflammatory bowel disease (IBD) as measured by the recently developed IBD disease-specific QOL measure the Inflammatory Bowel Disease Questionnaire (IBDQ).
Methods: Twenty-two patients (eight males and 14 females) were studied, 16 with Crohn's disease and six with ulcerative colitis (mean age 32 yr). Patients' disease activity was measured with the Dutch Crohn's activity index and the St. Mark's colitis activity index, and QOL was measured by the IBDQ. All patients completed self-report questionnaires for psychological function, which included the Sickness Impact Profile (SIP), the Symptom Checklist-90-R (SCL), and the Self-Control Schedule (SCS).
Results: By combining the psychological measures and the disease activity into a single variable, this composite variable significantly predicted QOL (r = 0.53, p < 0.02), but disease activity alone did not predict overall QOL. Improved psychosocial functioning (Sickness Impact Profile) predicted greater overall QOL (IBDQ total: r = -0.49, p < 0.05) and better social functioning (r = -0.65, p < 0.01). Greater psychological distress (SCL) and disease activity predicted more systemic symptoms [SCL-Positive Symptom Total (PST): r = -0.48, p < 0.05; disease activity: r = -0.65, p < 0.03) and poorer emotional functioning (SCL-PST: r = minus] 0.75, p < 0.001; disease activity: r = -0.82, p < .03). Disease type, gender, age of onset, and psychological coping (SCS) were not predictive of disease-specific QOL, but coping (SCS) was significantly correlated with psychological distress (r = -0.58, p < 0.05 for the SCL-90-PST).
Conclusion: This study confirms the importance of psychological functioning in determining QOL of IBD patients and must be considered jointly with disease activity.