Non-fatal health outcomes from diseases and injuries are a crucial consideration in
the promotion and monitoring of individual and population health. The Global Burden
of Disease (GBD) studies done in 1990 and 2000 have been the only studies to quantify
non-fatal health outcomes across an exhaustive set of disorders at the global and
regional level. Neither effort quantified uncertainty in prevalence or years lived
with disability (YLDs).
Of the 291 diseases and injuries in the GBD cause list, 289 cause disability. For
1160 sequelae of the 289 diseases and injuries, we undertook a systematic analysis
of prevalence, incidence, remission, duration, and excess mortality. Sources included
published studies, case notification, population-based cancer registries, other disease
registries, antenatal clinic serosurveillance, hospital discharge data, ambulatory
care data, household surveys, other surveys, and cohort studies. For most sequelae,
we used a Bayesian meta-regression method, DisMod-MR, designed to address key limitations
in descriptive epidemiological data, including missing data, inconsistency, and large
methodological variation between data sources. For some disorders, we used natural
history models, geospatial models, back-calculation models (models calculating incidence
from population mortality rates and case fatality), or registration completeness models
(models adjusting for incomplete registration with health-system access and other
covariates). Disability weights for 220 unique health states were used to capture
the severity of health loss. YLDs by cause at age, sex, country, and year levels were
adjusted for comorbidity with simulation methods. We included uncertainty estimates
at all stages of the analysis.
Global prevalence for all ages combined in 2010 across the 1160 sequelae ranged from
fewer than one case per 1 million people to 350,000 cases per 1 million people. Prevalence
and severity of health loss were weakly correlated (correlation coefficient -0·37).
In 2010, there were 777 million YLDs from all causes, up from 583 million in 1990.
The main contributors to global YLDs were mental and behavioural disorders, musculoskeletal
disorders, and diabetes or endocrine diseases. The leading specific causes of YLDs
were much the same in 2010 as they were in 1990: low back pain, major depressive disorder,
iron-deficiency anaemia, neck pain, chronic obstructive pulmonary disease, anxiety
disorders, migraine, diabetes, and falls. Age-specific prevalence of YLDs increased
with age in all regions and has decreased slightly from 1990 to 2010. Regional patterns
of the leading causes of YLDs were more similar compared with years of life lost due
to premature mortality. Neglected tropical diseases, HIV/AIDS, tuberculosis, malaria,
and anaemia were important causes of YLDs in sub-Saharan Africa.
Rates of YLDs per 100,000 people have remained largely constant over time but rise
steadily with age. Population growth and ageing have increased YLD numbers and crude
rates over the past two decades. Prevalences of the most common causes of YLDs, such
as mental and behavioural disorders and musculoskeletal disorders, have not decreased.
Health systems will need to address the needs of the rising numbers of individuals
with a range of disorders that largely cause disability but not mortality. Quantification
of the burden of non-fatal health outcomes will be crucial to understand how well
health systems are responding to these challenges. Effective and affordable strategies
to deal with this rising burden are an urgent priority for health systems in most
parts of the world.
Bill & Melinda Gates Foundation.
Copyright © 2012 Elsevier Ltd. All rights reserved.