Poor Correlation Between Clinical Disease Activity and Mucosal Inflammation, and the Role of Psychological Comorbidity, in Inflammatory Bowel Disease.

Abstract

There is a move toward patient-reported outcome measures as end points in clinical trials of novel therapies for inflammatory bowel disease (IBD). However, the association between patient-reported symptoms and mucosal inflammation, and the influence of psychological factors, remains unclear. We examined this in a secondary care population. Validated patient-reported disease activity indices were used to define clinically active disease in a cohort of 356 patients with ulcerative colitis (UC) or Crohn's disease (CD). A fecal calprotectin ≥250 μg/g was used to define active mucosal inflammation. The hospital anxiety and depression scale (HADS) and patient health questionnaire (PHQ)-15 were used to assess for anxiety, depression, or somatization, respectively. Logistic regression analysis was performed to determine the association between symptoms, mucosal inflammation, and psychological comorbidity. Clinical disease activity was associated with mucosal inflammation in UC (odds ratio (OR) 3.36; 95% confidence interval (CI) 1.34-8.47) but not in CD (OR 1.69; 95% CI 0.74-3.83). Depression in UC (OR 1.21 per 1-point increase in HADS; 95% CI 1.02-1.44) and somatization in UC (OR 1.17 per 1-point increase in PHQ-15; 95% CI 1.03-1.33) and CD (OR 1.31 per 1-point increase in PHQ-15; 95% CI 1.13-1.52) were associated with clinical disease activity. Overall, patient-reported symptoms yielded poor positive predictive values for mucosal inflammation in both CD and UC. Patient-reported symptoms and the Harvey-Bradshaw index were poor predictors of mucosal inflammation in CD. Psychological comorbidity was associated with gastrointestinal symptom-reporting. A shift in the focus of IBD management toward one addressing both psychological and physical well-being is required.