Background: Usefulness of a mobile monitoring system for Crohn's disease (CD) has not been evaluated. We aimed to determine whether activity graph patterns depicted at a web-based CD symptom diary (CDSD) could indicate disease clinical outcomes.
Methods: Patients with CD from 3 tertiary hospitals were prospectively invited to record their symptoms at CDSD site using a smart phone at least once a week. Activity patterns for at least 2 months were statistically classified into good (G) or poor (P) group based on two factors in two local windows; the first factor is the degree of score variation (maximum – minimum) at each window and the second factor is the trend (upward, stationary or downward) of patterns indicated by the difference of mean activity score between two windows. Clinical data regarding hospitalization, unscheduled hospital visit, and bowel surgery related with CD since study enrollment was retrospectively assessed by a medical personnel who blinded to results of CDSD. Association with outcomes was evaluated using logistic regression analysis.
Results: Among 309 patients invited, 266 who recorded their symptoms at least for 2 months were enrolled in the study (male 187; diagnosis age, mean yr, 23.6±8.7; follow-up, mean month, 39.9±10.1). Patient number of G and P group was 220 (82.7%) and 46 (17.3%), respectively. Baseline characteristics including sex, diagnosis age, location, and disease behavior were not different between groups. P group was significantly more associated with hospitalization (56.5% vs. 34.1%, p=0.004), unscheduled hospital visit (17.4% vs. 5.5%, p=0.011), and bowel surgery (19.6% vs. 1.8%, p<0.001) during follow-up period than G group. In multivariate analysis, P graph pattern (odds ratio (OR) 2.67, 95% confidence interval (CI) 1.36–5.27, p=0.005) complicating behavior (OR 2.92, 95% CI 1.69–5.04, p<0.001), and young diagnosis age (OR 1.05, 95% CI 1.02–1.09, p=0.003) were independently associated with hospitalization. P graph pattern (OR 4.06, 95% CI 1.50–10.99, p=0.006) and ileal location (OR 5.79, 95% CI 1.17–28.81, p=0.032) remained as independent risk factors for unscheduled visit. P graph pattern (OR 15.54, 95% CI 4.29–56.24, p<0.001) and complicating behavior (OR 6.13, 95% CI 1.49–25.17, p=0.012) were found to be independent risk factors for bowel surgery.
Conclusions: Activity graph pattern depicted at a web-based symptom diary is a useful indicator of poor clinical outcomes such as hospitalization, unscheduled hospital visit and bowel surgery in patients with CD.