Determining the Period Prevalence and Acuity of Emergency Department Visits Following Induced Abortion Mistakenly Identified as Spontaneous Abortion: An Analytic Observational Prospective Cohort Study

Background: Induced abortions via mifepristone and misoprostol (medical abortion) represented 63% of abortions in the United States in 2023.Women are consistently advised to conceal their recent abortion when visiting the Emergency Department (ED).Consequently, ED visits may be mistakenly attributed to a prior spontaneous abortion or miscarriage rather than induced abortion.Objectives: We sought to determine the period prevalence trajectory of these miscodes from 2004-2015 to 2016-2021.In addition, for the period 2016-2021, we sought to determine if there were differences in the severity or acuity of these miscoded visits compared to correctly classified post-abortion visits.Methods: We analyzed Centers for Medicare and Medicaid Services (CMS) Transformed Medicaid Statistical Information System Analytic Files (TAF) to identify 28,534 emergency department visits for all causes, and their level of acuity, following either a medical or surgical abortion within 30 days.For abortion-related visits, we determined whether the visits were miscoded as a spontaneous abortion or were correctly coded.Results: Between the two time periods, miscode period prevalence rates following medical abortion increased from 4.7% of total visits to 18.0%; and from 45.5% of abortion-related visits to 83.5%.Following surgical abortion, miscodes increased from 1.2% of all-cause visits to 7.7%; abortion-related miscodes increased from 26.8% to 73.9%.During the period 2016-2021, ED visits following medical abortion were more likely to be miscoded than visits following surgical abortion: for all-cause visits, OR 2.63, P<.001; for abortion-related visits, OR 1.79, P<.001.Miscoded ED visits had significantly higher acuity than correctly coded visits.For all-cause visits following medical abortion, OR 3.68, P<.001; for all-cause visits following surgical abortion, OR 3.39, P<.001.For abortion-related visits following medical abortion, OR 1.51, P=.006; for abortion-related visits following surgical abortion, OR 1.41, P=.03.Discussion: Coincident with the increasing dominance of medical abortion, there is a concurrent increase in the misattribution of post-induced abortion ED visits to a spontaneous abortion.High levels of visit acuity suggest that these miscodes represent a serious risk factor.Further, these miscodes mask and statistically deflate post-abortion complication rates and undermine both the science and medical management necessary to address these issues, representing a threat to effective surveillance.