Systematic review: has disease outcome in Crohn's disease changed during the last four decades?

Disease outcome in Crohn's disease might have changed during the last four decades. Disease outcome measurement in Crohn's disease has methodological difficulties because of patient selection and lack of proper definition of diagnostic and outcome measurement criteria. To assess possible changes in disease outcome in Crohn's disease during the last four decades. A systematic literature search was performed using the MEDLINE search engine and major international conference libraries. Articles and abstracts were selected according to stringent inclusion criteria. Forty articles and nine abstracts complied with the inclusion criteria. Seven studies with a median follow-up time between 11.1 and 17 years showed standard mortality ratios in Crohn's disease ranging between 2.16 and 0.72 with a tendency of decline during the last four decades. One study with 11.4 years mean follow-up time showed a statistically significant increased relative risk for colorectal cancer that was not confirmed by three others. Sixteen publications applied in the disease recurrence category. Probability of first resective surgery ranged between 38 and 96% during the first 15 years after diagnosis. The overall recurrence and surgical recurrence rates after first resective surgery ranged between 50 and 60, and 28 and 45% respectively during the following 15 years without an apparent time trend. This structured literature review provides no hard evidence for change in disease outcome in Crohn's disease during the last four decades.