Annual estimates of death, disability-adjusted life years (DALYs), years of life lost due to premature mortality (YLLs), and years lived with disability (YLDs) rate by age, sex, cause, and location (region, subregion, and country) from 2000 to 2019 were used to determine the top 15 causes impacting mortality and the burden of diseases.
Selection of the rankable list of causes
The selection of the rankable list of fatal and non-fatal diseases and conditions was guided by some principles.
First, it was based on the Global Health Estimates 2000-2019 cause list (WHO GHE, Annex Table A1, p 62), which is arranged in hierarchical nested categories with four levels. Level 1 includes three broad cause groups: communicable, maternal, neonatal, and nutritional conditions; noncommunicable diseases, and injuries. Within each of those categories, fatal and non-fatal causes of health loss are broken down with increasing specificity at each level. The GHE cause list is mutually exclusive and collectively exhaustive at every level of aggregation; causes not individually specified are captured in residual categories.
Second, the rankable list of causes includes cause categories with a sufficient level of detail or aggregation that can be actionable, are considered most useful from a public health perspective, and there is a balance in the level of aggregation across cause categories. Most of the level 3 categories from GHE cause list comply with this criteria. The rankable list must be mutually exclusive, so if a category containing subcategories is selected as rankable, its components parts of subcategories are not selected. Residual categories, those groups of causes containing unspecified diseases, for instance, all categories beginning with the words “Other”, are not included as rankable.
These cause categories were ranked using crude, age-specific, and age-standardized rates per 100,000 population of death, DALYs, YLLs, and YLDs.
- One DALY represents the loss of the equivalent of one year of full health. DALYs for a disease or health condition are the sum of YLLs due to premature mortality and YLDs due to prevalent cases of the disease or health condition in a population.
- The age-standardized mortality rate is a weighted average of the age-specific mortality rates per 100 000 persons, where the weights are the proportions of persons in the corresponding age groups of the WHO standard population. It enables the comparison of indicator values across countries and over time with different age structures of the population.