Estimating Abortion Incidence: Assessment of a Widely Used Indirect Method

Induced abortion is a reproductive behavior that remains difficult to measure in countries where the procedure is highly restricted by law. Additionally, in some countries where abortion is broadly legal, a high proportion of abortions are carried out by illegal and untrained providers. In these contexts, official statistics are non-existent or highly incomplete. Measurement of the incidence of induced abortion is essential to inform sexual and reproductive health policies and programs. Researchers have developed diverse methodologies over the years. Direct methods, such as population-based surveys that ask women about their abortion experience, generally are subject to high levels of underreporting. A range of indirect methods have been developed to obtain more accurate estimates. Created in the early 1990s, the Abortion Incidence Complications Method (AICM) is a widely applied indirect method that has produced robust estimates of abortion incidence in a range of contexts. This paper presents the original AICM methodology used in countries where abortion is highly restricted. It also highlights modifications made for two situations, one of which is newly emerging. First, the methodology has been adapted recently for countries where, despite the restrictive abortion laws, a new, relatively safe method—medication abortion (mainly misoprostol alone)—is increasingly used. Second, it has been adapted for countries where abortion is broadly legal but unsafe abortion remains common. The paper also assesses performance of the methodology to the extent available data permit. The paper provides guidance to researchers who want to conduct abortion incidence studies using the AICM and to further advance the measurement of abortion incidence.