Analysis of comorbid conditions associated with intrauterine device removal within an inpatient population

Background: Intrauterine devices (IUD) are an increasingly popular form of contraception in the US due to their high level of effectiveness, reversibility, and lack of further maintenance after insertion, but they are not without their adverse events. Previous studies have found that local adverse events following IUD insertion can be problematic enough that women choose to remove them. While much research has been done on IUDs and their related adverse events, in outpatient settings, no research has been done regarding comorbid conditions associated with their removal in an inpatient setting. Comorbidities associated with IUD removal may point to systemic long-term effects of IUD use that can be further explored. The primary objective of this study is to describe and examine the association of patient factors and comorbid conditions with inpatient IUD placement and removal compared to the inpatient controls. Methods: An analysis of data from the US National Inpatient Sample from 2010-2014 was performed looking for an association between various potential comorbidities (vascular, allergy/immune, and endometriosis) when the hospitalization includes an IUD insertion or no IUD procedure, compared to an IUD removal. The inpatient samples were matched using propensity score of having an IUD related ICD-9 code to create triplets of women with no IUD procedure, IUD insertion, and IUD removal. Results: IUD removal is associated with a decreased likelihood of hypertension, cardiovascular disease and peripheral vascular disease, and an increased likelihood of endometriosis compared to women without an IUD procedure indicating they may be adverse events of using an IUD leading to an IUD removed. There were no significant statistical interactions found between race and IUD group, though some trends between races were seen. Conclusion: As more women in the United States are choosing IUDs as their preferred contraceptive method, we have identified associated comorbid conditions among IUD users though we did not have strong evidence to support that these effects vary by race. This will have a public health impact by informing future research on the potential long-term systemic adverse events to allow women and their doctors to make their most informed decision about contraceptive use.