Glossary of key terms

Age-standardized rates permit comparison of disease burden intensity across populations after accounting for differences in age structure. Crude rates describe total burden without age adjustment and indicate the overall volume of health loss and service need associated with population size, aging, and growth.

Allocative efficiency refers to directing available resources toward higher-value health priorities through explicit priority-setting and health benefit package design. Technical efficiency refers to making better use of available resources in service delivery, including by reducing duplication and by sharing delivery platforms, inputs, and management functions across related interventions.

Avertable disease burden refers to the share of the disease burden that could be treated and managed appropriately through timely, quality health care or prevented altogether through effective public health actions and primary prevention.

Burden of disease is the quantification of health loss caused by diseases, injuries, and risk factors. It is typically measured using disability-adjusted life years (DALYs) as a summary measure of health loss, along with other key metrics such as mortality, years of life lost, and years lived with disability.

Cost-effectiveness analysis is an economic evaluation method that compares the costs and health outcomes of two or more interventions or alternatives. Results are commonly expressed as the additional cost per additional unit of health gained, such as cost per DALY averted, death averted, or healthy life year gained.

A delivery platform is the organized set of service settings and delivery arrangements through which a priority service bundle is implemented. A platform identifies where and through which arrangements services are delivered. Examples include population-level action, community and outreach services, primary care, emergency and hospital care, specialist services, referral networks, and rehabilitation services.

One DALY represents the loss of one year of full health and is also referred to as “health loss” in this report. For any disease or health condition, DALYs are calculated as the sum of years of life lost due to premature mortality (YLLs) and years lived with disability (YLDs) among prevalent cases in a population.

DALYs are therefore interpreted as years of healthy life lost and are useful for comparing overall health loss across causes, populations, and time. However, they should not be interpreted as a direct measure of health system performance without considering risk factors, social determinants, demographic structure, and other contextual factors.

Extended cost-effectiveness analysis is a variation of standard cost-effectiveness analysis by adding an equity perspective. It evaluates not only the aggregate health gains relative to costs but also how health gains and financial risk protection benefits are distributed across different population groups.

Financial hardship is an indicator of inadequate financial risk protection. Households face financial hardship when out-of-pocket health spending reduces people’s ability to meet basic needs or afford other goods and services. It is measured as the share of the population with out-of-pocket household health expenditures exceeding 40% of a household’s discretionary budget. When out-of-pocket health expenditures exceed 40% but remain below 100% of a household’s discretionary budget, the financial hardship is referred to as “large spending.” When it exceeds 100% of a household’s discretionary budget – either by people already in poverty who have no discretionary budget or by those pushed into poverty by their health expenses – it is referred to as “impoverishing spending.”

Financial protection refers to shielding individuals and households from catastrophic or impoverishing out-of-pocket health spending when obtaining needed health services.

GBD Level 2 causes are broad cause categories used in the Institute for Health Metrics and Evaluation’s GBD study that group related diseases and conditions to support consistent regional and cross-country comparisons. For example, “cardiovascular diseases” includes ischemic heart disease, stroke, hypertensive heart disease, cardiomyopathy and myocarditis, rheumatic heart disease, and other cardiovascular conditions. “Diabetes and kidney diseases” includes diabetes mellitus, acute glomerulonephritis, and chronic kidney disease, with chronic kidney disease further disaggregated by etiology.

Governance refers to the institutional arrangements, processes, structures, and relationships that regulate health system actors and resources and enable strategic direction, supervision, regulation, and accountability.

HALE is the number of years that a person at a given age can expect to live in good health, assuming the rates of all-cause mortality and all-cause disability in a given year remain constant into the future. HALE is also referred to as “healthy life expectancy” in this report.

A health benefit package is a set of health services and interventions that are covered, guaranteed, or otherwise prioritized. A health benefit package principally defines what a health system intends to provide and to whom, often together with eligibility, financing, and entitlement arrangements.

HTA is a multidisciplinary process that systematically evaluates the clinical, economic, organizational, social, and ethical implications of health technologies, such as medicines, diagnostics, medical devices, procedures, and digital health tools.

A healthy life year gained is a measure of modeled health gain reported by the World Health Organization’s OneHealth Tool, combining gains from longer life and reduced disability. It is conceptually related to DALYs averted but not treated as methodologically identical in this report.

Impoverishing health spending is out-of-pocket health spending that pushes households into poverty or maintains them in poverty. It is measured as out-of-pocket health spending that exceeds 100% of a household’s discretionary budget – either by people already in poverty who have no discretionary budget or by those pushed into poverty by their health expenses.

An integrated health service delivery network is a coordinated network linking first-contact care, community and outreach services, referral and counter-referral arrangements, hospitals, specialist care, emergency care, and rehabilitation to provide continuous and integrated services centered on primary health care.

Life expectancy at birth is the average number of years a newborn is expected to live, assuming age-specific mortality rates remain constant.

Out-of-pocket expenditure refers to payments made directly by people when using health services or goods from any provider. This includes cost-sharing (i.e., the portion not covered by insurance or other third parties) and informal payments but excludes insurance premiums and any reimbursements from third parties, such as the government, a health insurance fund, or a private insurance company.

Potentially avertable DALYs represent the difference between a country’s actual burden for each GBD Level 2 disease or health condition and a performance benchmark for the same disease or health condition. The performance benchmark is defined in this report as the 10th percentile of age-standardized DALY rates across 204 countries and territories worldwide in 2023. In practical terms, the defined benchmark represents a comparatively strong performance level that has already been observed globally for the same disease/health condition.

The measure represents improvement potential based on demonstrated international performance. It is not a prediction of the impact of any specific intervention, an operational target that countries are expected to close in full, or a burden proven to be immediately or fully preventable. It also does not attribute gaps solely to health system performance.

Note: This concept differs from potentially avoidable premature mortality used in Health in the Americas: Potentially avoidable premature mortality, which was an age-restricted indicator of deaths among people under 75 years from a defined list of causes considered preventable or treatable. This 2026 edition instead uses a benchmark-based DALY measure that encompasses both fatal and nonfatal health loss.

WHO defines primary health care (PHC) as a whole-of-government and whole-of-society approach to health that addresses people’s health needs across the life course, from health promotion and disease prevention to treatment, rehabilitation, and palliative care, as close as feasible to people’s everyday environment. PHC is organized around three interdependent components: multisectoral policy and action; empowered people and communities; and integrated health services, with an emphasis on primary care services and essential public health functions.

A priority service bundle is an operational grouping of prioritized health services and public health actions that address related health needs through shared or coordinated delivery requirements. These requirements include workforce capacities, medicines and health technologies, clinical and public health protocols, referral pathways, information systems, and management functions. A bundle describes how selected services and actions are organized for implementation. Depending on the health needs addressed, a bundle may combine services provided through different delivery platforms.

Priority-setting is a deliberative process to set health priorities combining evidence with transparent and ethical procedures, stakeholder engagement, and broader judgments about legitimacy and fairness. It considers multiple criteria including disease burden, improvement potential, equity, financial risk protection, effectiveness, value, affordability, and delivery capacity.

Rationing refers to restricting access to health services, whether explicitly through policy decisions or implicitly through resource constraints or administrative barriers.

WHO defines social determinants of health as the circumstances in which people are born, grow, live, work, and age, and people’s access to power, money, and resources. These factors include social class, gender, race, ethnicity, income, educational attainment, working conditions, housing quality, and other impacts on day-to-day living. Individual behavioral choices and health system resources also matter, operating within these broader social and economic contexts.

The SDI is a composite measure of development status that combines fertility rates for those under 25 years, average educational attainment for those 15 years and older, and lag distributed income per capita. The SDI ranges from 0 (lowest) to 1 (highest) and is strongly correlated with health outcomes.

Stewardship refers to the leadership, political, and technical capacity of national and subnational health authorities to set strategic direction, foster collaboration, shape health system design, provide oversight and regulation, and mobilize resources to translate priorities into results.

The SHIx is a composite measure capturing differences between countries in health status, service coverage, socioeconomic conditions, inequality, and environmental determinants. The index is based on six dimensions: health outcomes, measured using health-adjusted life expectancy (HALE); health access, measured using the Universal Health Coverage (UHC) Service Coverage Index; inequality, measured as 100 minus the Gini coefficient; economic capacity, measured using log10 gross national income (GNI) per capita; social conditions, measured using years of educational attainment; and environmental conditions, measured using access to water and sanitation services. Each dimension is standardized to a 0–⁠1 (lowest to highest) scale using goalposts.

UHC means ensuring all people have access to the full range of quality health services they need – from health promotion and prevention to treatment, rehabilitation, and palliative care across the life course – when and where they need them, without financial hardship.

YLD is a measure of nonfatal health loss calculated by combining the prevalence of disease sequelae and disability weights reflecting the severity of the disease.

YLL is a measure of premature mortality calculated by multiplying the number of deaths at each age by the standard remaining life expectancy at that age. Deaths occurring at younger ages therefore contribute more YLL than deaths at older ages.