Inflammatory bowel disease (IBD) was shown to be associated with a variety of chronic comorbidities. We aimed to evaluate the frequency of 21 chronic conditions and compared frequencies in IBD and non-IBD populations. Further, healthcare costs of those (additional) chronic conditions were calculated.
A total of 4791 IBD patients, who were insured at Helsana Insurance Group in 2014, were compared with 1 114 638 individuals without IBD. Entropy balancing was performed to create balanced samples. Chronic conditions were identified by means of the updated Pharmacy-based Cost Group model. Multivariate log-transformed linear regression modeling was performed to estimate the effect of the morbidity status (non-IBD +none, +1, +2, and +3 or more chronic conditions) on the healthcare costs.
Overall, 78% of IBD patients had at least one comorbidity, with a median of three comorbidities. Largest differences between individuals with and without IBD were found for rheumatologic conditions, acid-related disorders, pain, bone diseases, migraines, cancer, and iron-deficiency anemia, whereas no significant differences between the two groups were found for diabetes, dementia, hyperlipidemia, glaucoma, gout, HIV, psychoses, and Parkinson's disease after adjustments for a variety of covariates. Each increase in the morbidity status led to increased healthcare costs; rheumatologic conditions, acid-related disorders, and pain as the most frequent comorbidities more than doubled total costs in IBD patients.
We found a considerably high prevalence of concomitant chronic diseases in IBD patients. This was associated with considerably higher healthcare costs, especially in the outpatient setting.