High burden of iron deficiency and different types of anemia in inflammatory bowel disease outpatients in Scandinavia: A longitudinal 2-year follow-up study

Objective. The prevalence of anemia in inflammatory bowel disease (IBD) has been broadly described. The recurrence, type and burden of anemia remain unenlightened. The primary objective was to describe this. The secondary objective was to evaluate the implementation of European guidelines. Materials and methods. This longitudinal follow-up study included 300 IBD outpatients from six centers in Scandinavia. Patients were enrolled in a research cohort, in which each center included 5% of their IBD cohort. The study was prospectively planned, while data were retrospectively collected. The burden of anemia was calculated as number of months with anemia. A Markov model was used to calculate the probabilities of transitioning between stages. The European guidelines were used as the standard for anemia management. Results. Anemia affected > 50% of IBD outpatients during the 2-year observation period. Totally, 20% of the total observation time was spent in anemia. Over the 7200 months of observation, anemia was found in 1410 months. The most frequent type was combined anemia (63%). Combined anemia covers both anemia of chronic disease (ACD) and iron-deficiency anemia (IDA). Pure ACD was present in 21% of burden time, while pure IDA was present in 16% of burden time. The European guidelines have mainly been implemented. Conclusion. Anemia affected a majority of the IBD outpatients. One in five months, the patients were anemic. Anemia related to inflammation dominated the different types of anemia. Pure IDA was found in for 16%. These findings, despite a fair implementation of guidelines