Trends in use of medical abortion in the United States: reanalysis of surveillance data from the Centers for Disease Control and Prevention, 2001-2008

Background: With changing patterns and increasing use of medical abortion in the United States, it is important to have accurate statistics on the use of this method regularly available. This study assesses the accuracy of medical abortion data reported annually to the Centers for Disease Control and Prevention (CDC) and describes trends over time in the use of medical abortion relative to other methods. Study Design: This analysis included data reported to CDC for 2001-2008. Year-specific analyses included all states that monitored medical abortion for a given year, while trend analyses were restricted to states that monitored medical abortion continuously from 2001 to 2008. Data quality and completeness were assessed by (a) examining abortions reported with an unspecified method type within the gestational age limit for medical abortion (med-eligible abortions) and (b) comparing the percentage of all abortions and med-eligible abortions reported to CDC as medical abortions with estimates based on published mifepristone sales data for the United States from 2001 to 2007. Results: During 2001-2008, the percentage of med-eligible abortions reported to CDC with an unspecified method type remained low (1.0%-2.2%); CDC data and mifepristone sales estimates for 2001-2007 demonstrated strong agreement [all abortions: intraclass correlation coefficient (ICC)=0.983; med-eligible abortions: ICC=0.988]. During 2001-2008, the percentage of abortions reported to CDC as medical abortions increased (p<.001 for all abortions and for med-eligible abortions). Among states that reported medical abortions for 2008, 15% of all abortions and 23% of med-eligible abortions were reported as medical abortions. Conclusion: CDC's Abortion Surveillance System provides an important annual data source that accurately describes the use of medical abortion relative to other methods in the United States. Published by Elsevier Inc.