Association between disease activity and quality of life in ulcerative colitis: Results from the CRONICA-UC study

In ulcerative colitis (UC), the main goals of treatment are to control disease activity and normalize health-related quality of life (HRQoL). In this study, we explored the relationship between disease activity (measured using the Simple Clinical Colitis Activity Index [SCCAI]) and patient HRQoL (measured using the EuroQoL [EQ]-5D-5L).

A total of 199 patients with UC were followed for 6 months. At months 3 and 6, patients completed an online SCCAI. Within 2 days of completing the SCCAI, patients completed an at-clinic EQ-5D-5L questionnaire and the treating gastroenterologist completed the SCCAI.

A consistent and approximately linear relationship was identified between patient HRQoL and patient-completed and physician-completed SCCAIs. A lower SCCAI score corresponded to a higher EQ-5D-5L index value. Correlation between EQ-5D-5L index values and patient-completed online SCCAIs was moderate (ρ -0.49; P < 0.001) and similar to that between EQ-5D-5L index values and physician-completed SCCAIs (ρ -0.53; P < 0.001). A decrease in the EQ-5D-5L index was already observed at an SCCAI score of 2, commonly regarded as remission. A 1-point increase in the patient SCCAI corresponded to an average change of -0.027 (standard deviation, -0.032 to -0.022) in the EQ-5D-5L index, whereas a 1-point increase in the physician SCCAI corresponded to an average change of -0.030 (standard deviation, -0.036 to -0.025).

Health-related quality of life measured using the EQ-5D-5L questionnaire is proportionally related to disease activity in patients with UC. In line with the treat-to-target objective in UC, complete control of all symptoms is required to achieve optimal improvement in patient HRQoL.