Introduction The Harvey-Bradshaw index (HBI) and simple clinical colitis activity index (SCCAI) are clinical scoring systems used to estimate Crohn’s disease (CD), and ulcerative colitis (UC) activity, respectively. However, whether they are superior to the patient’s own opinion at predicting disease activity, defined by faecal biomarkers of inflammatory bowel disease (IBD) activity is unclear. We conducted a cross-sectional survey of IBD patients to assess these issues.

Method Patient opinion as to whether they were, or were not experiencing a flare of disease was recorded in 245 patients. Active disease was defined as a HBI or SCCAI score of ≥5 for CD and UC respectively. Stool was collected for faecal calprotectin (FC) analysis by enzyme linked immunosorbent assay (Biohit, Finland), with patients dichotomised into those with or without active disease, using a FC of ≥200 µg/g of stool to define active disease. The sensitivity, specificity, positive and negative predictive values, and overall accuracy of patient opinion and clinical activity indices at predicting disease activity defined by FC was calculated. A ROC curve for HBI and SCCAI against disease activity defined by FC was used to calculate the AUC for each clinical assessment index. Mean FC was compared between those with and without active disease by patient opinion and clinical indices of IBD activity by independent samples t-test.

Results The sensitivity, specificity, positive and negative predictive value, overall test accuracy and AUC for each test when used to predict disease activity defined by FC is illustrated in Table 1. In CD, mean FC was lower in patients with active disease defined by HBI than those without (381 vs. 472; P = 0.368), but higher in patients with active disease defined by patient opinion than those without (474 vs. 425; P = 0.711). In contrast, mean FC was significantly higher in UC patients with active disease defined by both patient opinion and SCCAI (919 vs. 381; P < 0.001 and 949 vs. 311; P < 0.001 respectively).

Conclusion The performance of clinical disease activity indices at predicting IBD activity was modest in UC and poor in CD when compared with faecal biomarkers of intestinal inflammation. Neither HBI nor SCCAI outperformed patient opinion in the assessment of disease activity. Faecal biomarker point of care testing may aid clinical decision making.

Disclosure of interest None Declared.