Prospective Evaluation of the Prediction Score for a Mild Course of Crohn's Disease (PreMiCC) in Newly Diagnosed Patients With Crohn's Disease: The PROGNOS Study

Background and Aims: The course of Crohn's disease (CD) is highly variable. The Prospektive Evaluation eines Score zur Vorhersage eines milden Verlaufsbei neu diagnostizierten Morbus Crohn-Patienten in gastroenterologischen Fachpraxen (PROGNOS) study aimed to determine the frequency of a mild disease course and validate a proposed prediction score. Methods: The PROGNOS study is a prospective study of CD patients who were newly diagnosed and, except for 1 course of 5-aminosalicylic acid or steroids for <= 10 days, therapy-naive. Among other predefined inclusion criteria, the initial diagnosis had to be made <= 6 weeks before enrollment. All inception cohort patients were diagnosed and screened consecutively in participating gastroenterology practices in Germany specialized in inflammatory bowel disease. All screened CD patients were scored and, if possible, included in the study for up to 5 years (NCT02193048). Results: A total of 201 CD patients were included in the study (43.3% male; mean age 33 years, mean follow-up 38 months). Altogether, 29.5% of the patients had a mild course at 36 months. Among those with a score <= 2, therapy escalation at 36 months was necessary for only 24.2%, whereas in the group with a score >2, therapy escalation was necessary for 70.2% of patients. In the Kaplan-Meier curve showing time to therapy escalation in the 2 groups, there was a pronounced and statistically significant divergence of the curves starting at 3 months and extending to 48 months (P < .001). Conclusions: In this prospective study, about 30% of incident CD patients had a mild disease course. Our suggested PreMiCC (prediction score for a mild course of Crohn's disease) successfully predicted this. Lay Summary In our study of newly diagnosed Crohn's disease patients, we found that around 30% had a mild disease course. We also successfully tested our proposed PreMiCC (prediction score for a mild course of Crohn's disease), which predicts this mild course