Predictors of symptom trajectory in newly diagnosed ulcerative colitis: a 3-year follow-up cohort study

Abstract Background and Aims Psychological symptoms are associated with poorer ulcerative colitis [UC]-related outcomes. However, the majority of research is cross-sectional. We aimed to identify subgroups based on the longitudinal evolution of GI symptom levels and health-related quality of life [HRQoL], and to disentangle the directionality of effects between GI symptom levels and psychological distress. Methods Self-reported gastrointestinal [GI] symptom severity, HRQoL, inflammatory biomarkers, and psychological distress were assessed in 98 newly diagnosed UC patients at disease onset and yearly for 3 consecutive years. Latent class growth analysis was used to determine subgroups based on longitudinal trajectories of symptom severity and HRQoL, and baseline predictors of trajectory group membership were determined. Cross-lagged structural equation models were used to disentangle temporal relationships between psychological functioning and symptom severity. Results Patients with higher initial psychological distress had increased probability of maintaining higher levels of diarrhoea and abdominal pain. Conversely, patients with lower initial levels of diarrhoea and abdominal pain had higher chances of maintaining lower levels of psychological distress. Higher levels of C-reactive protein at baseline predicted greater improvements in mental health after anti-inflammatory treatment. Reductions in diarrhoea and abdominal pain preceded reductions in psychological symptoms over time. Conclusions Baseline psychological distress is predictive of increased GI symptom severity and reduced mental HRQoL over time, suggesting early assessment of psychological symptoms may identify patients who may have worse disease trajectories. Abdominal pain predicted increased psychological distress, but not the other way around. Intervening on abdominal pain may help prevent or reduce future psychological distress.