To Örebro University

BACKGROUND: Treatment of patients with Crohn's disease has evolved in recent decades, with increasing use of immunomodulatory medication since 1990 and biologicals since 1998. In parallel, there has been increased use of active disease monitoring. To what extent these changes have influenced the incidence of primary and repeat surgical resection remains debated.

METHODS: In this nationwide cohort study, incident patients of all ages with Crohn's disease, identified in Swedish National Patient Registry between 1990 and 2014, were divided into five calendar periods of diagnosis: 1990-1995 and 1996-2000 with use of inpatient registries, 2001, and 2002-2008 and 2009-2014 with use of inpatient and outpatient registries. The cumulative incidence of first and repeat abdominal surgery (except closure of stomas), by category of surgical procedure, was estimated using the Kaplan-Meier method.

RESULTS: Among 21 273 patients with Crohn's disease, the cumulative incidence of first abdominal surgery within 5 years of Crohn's disease diagnosis decreased continuously from 54·8 per cent in 1990-1995 to 40·4 per cent in 1996-2000 (P < 0·001), and again from 19·8 per cent in 2002-2008 to 17·3 per cent in 2009-2014 (P < 0·001). Repeat 5-year surgery rates decreased from 18·9 per cent in 1990-1995 to 16·0 per cent in 1996-2000 (P = 0·009). After 2000, no further significant decreases were observed.

CONCLUSION: The 5-year rate of surgical intervention for Crohn's disease has decreased significantly, but the rate of repeat surgery has remained stable despite the introduction of biological therapy.