Universal health coverage and incarceration.

Global progress towards universal coverage of essential health services, a component of UN Sustainable Development Goal (SDG) 3.8, is measured at the country level using the WHO Service Coverage Index. However, data collection for this crucial metric excludes prisons and youth detention centres, despite the health needs in these settings, chronic underinvestment in custodial health care, and poor health outcomes for people released from custody in most countries. Particularly in countries with high incarceration rates, failure to include custodial settings in calculations of the service coverage index might result in overestimation of progress towards SDG 3.8.1, and mask important health inequalities. In this Viewpoint, we explore how failure to consider custodial settings in calculation of the service coverage index contributes to health inequalities and impedes progress towards SDG 3. We recommend explicitly considering all custodial settings in future estimates of progress towards universal health coverage.