Global, regional, and subregional classification of abortions by safety, 2010-14: estimates from a Bayesian hierarchical model

Abstract

Background: Global estimates of unsafe abortions have been produced for 1995, 2003, and 2008. However, reconceptualisation of the framework and methods for estimating abortion safety is needed owing to the increased availability of simple methods for safe abortion (eg, medical abortion), the increasingly widespread use of misoprostol outside formal health systems in contexts where abortion is legally restricted, and the need to account for the multiple factors that affect abortion safety.

Methods: We used all available empirical data on abortion methods, providers, and settings, and factors affecting safety as covariates within a Bayesian hierarchical model to estimate the global, regional, and subregional distributions of abortion by safety categories. We used a three-tiered categorisation based on the WHO definition of unsafe abortion and WHO guidelines on safe abortion to categorise abortions as safe or unsafe and to further divide unsafe abortions into two categories of less safe and least safe.

Findings: Of the 55· 7 million abortions that occurred worldwide each year between 2010-14, we estimated that 30·6 million (54·9%, 90% uncertainty interval 49·9-59·4) were safe, 17·1 million (30·7%, 25·5-35·6) were less safe, and 8·0 million (14·4%, 11·5-18·1) were least safe. Thus, 25·1 million (45·1%, 40·6-50·1) abortions each year between 2010 and 2014 were unsafe, with 24·3 million (97%) of these in developing countries. The proportion of unsafe abortions was significantly higher in developing countries than developed countries (49·5% vs 12·5%). When grouped by the legal status of abortion, the proportion of unsafe abortions was significantly higher in countries with highly restrictive abortion laws than in those with less restrictive laws.

Interpretation: Increased efforts are needed, especially in developing countries, to ensure access to safe abortion. The paucity of empirical data is a limitation of these findings. Improved in-country data for health services and innovative research to address these gaps are needed to improve future estimates.

Funding: UNDP/UNFPA/UNICEF/WHO/World Bank Special Programme of Research, Development and Research Training in Human Reproduction; David and Lucile Packard Foundation; UK Aid from the UK Government; Dutch Ministry of Foreign Affairs; Norwegian Agency for Development Cooperation.

Figure 1

Schematic representation of the framework for estimating the distribution of abortion by safety categories *Other covariates considered for the model but not used for conceptual, data, or statistical reasons are shown in the appendix.

Figure 2

Sources of empirical data

Figure 3

Distribution of abortion safety categories worldwide and by region Bars and dots show the point estimates of the proportion of abortions in each category and horizontal lines are 90% uncertainty intervals.

Figure 4

Distribution of abortion safety categories by subregion Bars and dots show the point estimates of the proportion of abortions in each category and horizontal lines are 90% uncertainty intervals.

Figure 5

Distribution of abortion safety categories for countries grouped by legal status Countries in group 1 did not allow abortion or only allowed it to save a woman's life or for physical health. Countries in group 2 allowed abortion on socioeconomic grounds or for mental health reasons. Countries in group 3 allowed abortion on request. Bars and dots show the point estimates of the proportion of abortions in each category and horizontal lines are 90% uncertainty intervals.

Figure 6

Distribution of abortion safety categories for countries grouped by level of gross national income Bars and dots show the point estimates of the proportion of abortions in each category and horizontal lines are 90% uncertainty intervals.

Figure 7

Distribution of the proportion of safe abortions and the incidence of abortion by UN DESA, Population Division subregion Abortion incidence was the number of abortions occurring each year per 1000 women aged 15–55 years. Data for abortion incidence came from reference 11. UN DESA=UN Department of Economic and Social Affairs.

Figure 8

Distribution of the proportion of least-safe abortions and case fatality rate by UN DESA, Population Division subregion Case fatality rate was defined as the number of abortion-related deaths per 100 000 abortions. UN DESA=UN Department of Economic and Social Affairs.