Correlations Between Clinical Activity Indices or Quality of Life Scores to Endoscopic Activity Scores Do not Vary According to Age at Diagnosis, Disease Location, and Disease Behavior in Inflammatory Bowel Disease

Abstract

Introduction: Clinical presentation and natural history of inflammatory bowel disease (IBD) vary based on age at diagnosis and disease location and phenotype. Clinical activity indices (CAIs) and quality of life (QOL) scores in Crohn's disease (CD) and ulcerative colitis (UC) are used to assess disease activity and response to treatment. However, there is a paucity of data on the validity of these indices according to various disease characteristics. We therefore sought to compare the correlations between QOL and CAIs along with endoscopic disease activity (EDA) according to age at diagnosis and disease location and behavior.Figure 1Figure 2Methods: We used the Prospective Registry in IBD Study at Massachusetts General Hospital (PRISM) to identify all IBD patients >17 years old. For CAIs, we used the Harvey-Bradshaw Index (HBI) for CD and simple clinical colitis activity index (SCCAI) for UC. Information on inflammatory markers, QOL scores derived from short IBD questionnaire (SIBDQ), Mayo endoscopic score, and simple endoscopic score (SES) were ascertained at the time of collection of disease activity indices. We used Spearman rank correlation to calculate the correlations across various indices and Fisher transformation to compare the correlations across disease characteristics. Results: 283 CD and 227 UC patients were included in the study. Correlations between CAIs and QOL scores to EDA scores were 0.18 (p=0.006) and -0.17 (p < 0.01) for CD and 0.55 (p < 0.001) and -0.56 (p < 0.001) for UC, respectively. In CD, we did not observe a difference in correlations between CAI and EDA scores according to age at diagnosis, disease location and behavior (All P>0.10). In UC, there was good correlation between CAI and EDA scores across different categories and statistically significant difference when comparing these correlations between patients with extensive and left-sided colitis (p=0.005). We observed similar correlations between inflammatory markers and EDAs according to age at diagnosis and disease location and behavior in UC and CD (All P>0.10). Conclusion: Our data suggest good correlations between SCCAI or SIBDQ and Mayo scores in UC, independent of age at diagnosis. We observed poor correlations between HBI or SIBDQ and SES scores in CD and this appeared unchanged with age at diagnosis or disease behavior. Despite significant heterogeneity in disease presentation, our findings suggest the validity of CAI and QOL indices is similar across various disease characteristics.