Predicting relapse in Crohn's disease: a biopsychosocial model

Background: Crohn's disease (CD) is a chronic relapsing inflammatory bowel disorder. Both biological and psychosocial factors may modulate the illness experience. Aim: The aim of this study was to identify clinical, biological and psychosocial parameters as predictors of clinical relapse in quiescent CD. Methods: Patients in medically induced remission were followed prospectively for 1 year, or less if they relapsed. Disease characteristics were determined at baseline. Serum cytokines, anti-Saccharomyces cerevisiae antibodies, C-reactive protein (CRP), erythrocyte sedimentation rate and intestinal permeability were measured every 3 months. Psychological distress, perceived stress, minor life stressors and coping strategies were measured monthly. A time-dependent multivariate Cox regression model determined predictors of time to relapse. Results: 101 patients (60 females, 41 males) were recruited. Fourteen withdrew and 37 relapsed. CRP (HR= 1.5 per 10 mg/l, 95% CI 1.1 to 1.9, p= 0.007), fistulising disease (HR= 3.2, 95% CI, 1.1 to 9.4, p= 0.04), colitis (HR= 3.5 95% CI 1.2 to 9.9, p= 0.02) and the interaction between perceived stress and avoidance coping (HR= 7.0 per 5 unit increase for both scales, 95% CI 2.3 to 21.8, p= 0.003) were predictors of earlier relapse. Conclusions: In quiescent CD, a higher CRP, fistulising disease behaviour and disease confined to the colon were independent predictors of relapse. Moreover, patients under conditions of low stress and who scored low on avoidance coping (ie, did not engage in social diversion or distraction) were least likely to relapse. This study supports a biopsychosocial model of CD exacerbation.