Epidemiologic Associations Between Inflammatory Bowel Disease and Hodgkin Lymphoma or Multiple Sclerosis

Background and Aims: Epidemiologic evidence suggests that Hodgkin lymphoma (HL) and multiple sclerosis (MS) share a common set of risk factors with Crohn’s disease (CD) and ulcerative colitis (UC). It was hypothesized that such shared risk factors would lead to similar geographic distributions of these 4 diagnoses and their concurrence in identical patients. Methods: All subjects with HL, MS, CD, or UC were identified in the complete Inpatient Standard Analytic File of the Centers for Medicare and Medicaid Services from 2018. In a cross-sectional study, we evaluated whether the frequencies of HL, MS, CD, and UC occurrences among different US states were statistically correlated with each other. In a case-control study, the observed concurrences of each 2 of the 4 diagnoses were compared with their expected frequencies in the overall Medicare population by calculating odds ratios with their 95% confidence intervals. Results: The total Centers for Medicare and Medicaid Services population comprised 6,462,321 unique patients, of whom 8027 presented with HL, 42,934 with MS, 40,623 with CD, and 32,521 with UC. Statistically significant positive correlations (r) with P < .001 were found between HL and MS (r = 0.50), HL and CD (0.46), HL and UC (0.68), MS and CD (0.66), MS and UC (0.72), and CD and UC (0.68). Any inflammatory bowel disease was significantly associated with a diagnosis of concurrent HL (odds ratio: 1.22, 95% confidence interval: 1.01–1.48) or MS (1.35, 1.25–1.46). Conclusion: The epidemiologic associations of inflammatory bowel disease with HL or MS may reflect a common pathway in the etiology or pathogenesis of these diseases.