Child, Maternal, and Adult Mortality in Sierra Leone: Nationally Representative Mortality Survey 2018-2020

Background: Sierra Leone’s child and maternal mortality rates are among the highest in the world. Yet little is known about the causes of premature mortality in the country. Methods: The Countrywide Mortality Surveillance for Action platform established the Sierra Leone Sample Registration System (SL-SRS), which involved conducting electronic verbal autopsies in 678 randomly selected villages and urban blocks throughout the country. 61 surveyors enrolled 343,000 households and ascertained 8347 deaths below age 70 in 2019-20, capturing deaths from 2018 to 2020; two trained physicians assigned causes of death (ICD-10). SL-SRS death proportions were applied to United Nations total mortality to derive cause-specific totals and risks of death nationally and in four regions, with comparisons made to Western region, where Freetown, the capital, is located. Findings: Malaria was the leading cause of death in children and adults, nationally and in each region, representing 23% of deaths below age 70 years in 2020. Other infections accounted for an additional 14%. Maternal mortality (510 per 100,000 live births) and neonatal mortality (31 per 1000 live births), among the highest rates in the world, were dominated by avoidable causes. Excess deaths were not detected concordant with the COVID-19 pandemic. Half of the deaths occurred in rural areas and at home. Had the Northern, Eastern, and Southern regions of Sierra Leone had the same lower death rates as the Western region, about 20,000 deaths (just over a quarter of national totals <70 years) would have been avoided. World Health Organization model-based data vastly underestimated malaria deaths, as well as some specific causes of injury deaths, and substantially overestimated maternal mortality. Interpretation: Over 60% of Sierra Leoneans die prematurely, before age 70, the majority from preventable or treatable causes. Nationally representative mortality surveys are of high value in providing reliable cause-of-death information to improve life expectancy in low-income countries.Funding Information: Bill & Melinda Gates Foundation, CIHR, Queen Elizabeth Scholarship Program.Declaration of Interests: We declare no competing interests.