Supplementary Material for: Endometriosis, Raynaud’s Syndrome and Migraine: A Retrospective Study of 12 Million Women

Objective: Our study focused on evaluating a possible relationship between endometriosis, Raynaud’s syndrome or migraine among women.
Design: This was a cross-sectional population-based study.
Participants/Materials, Setting, Methods: We used 12,684,067 hospitalized patient records in the Healthcare Cost and Utilization Project (HCUP) database between 2007 and 2014. We calculated the prevalence of endometriosis, Raynaud’s syndrome and migraine. We also evaluated the possible role of depression, anxiety and autoimmune diseases to eliminate confounding factors. Unadjusted and adjusted multivariate logistic regression were applied to evaluate the relationship between variables.
Results: Unadjusted analysis revealed a strong association between endometriosis and Raynaud’s syndrome and migraine. (OR=2.491 95%CI 1.677-3.699). After adjusting for sociodemographic characteristics as well as depression and anxiety, the association remained significant (OR=1.779; 95%CI 1.166-2.716). Among younger patients aged 18–35 with endometriosis, the associations were stronger with Raynaud's Syndrome (adjusted OR = 1.61, 95% CI = 1.20–2.16) and migraine (adjusted OR = 2.59, 95% CI = 2.47–2.72).
Limitations: The HCUP database is cross-sectional in nature, and hence, we could not establish the temporal relationship between endometriosis, Raynaud’s syndrome and migraine. Also, the severity of endometriosis and the treatment received by the patients were not included in the dataset, and it prevented us from investigating the role of potential confounding factors.
Conclusion: Our study suggests an association between endometriosis, Raynaud’s syndrome and migraine. It is possible that these conditions share a similar mechanism possibly vascular reaction and endothelial dysfunction related to chronic inflammation.