Papers by Mohammad Tavakkoli
Background Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary poli... more Background Established in 2000, Millennium Development Goal 4 (MDG4) catalysed extraordinary political, fi nancial, and social commitments to reduce under-5 mortality by two-thirds between 1990 and 2015. At the country level, the pace of progress in improving child survival has varied markedly, highlighting a crucial need to further examine potential drivers of accelerated or slowed decreases in child mortality. The Global Burden of Disease 2015 Study (GBD 2015) provides an analytical framework to comprehensively assess these trends for under-5 mortality, age-specifi c and cause-specifi c mortality among children under 5 years, and stillbirths by geography over time.
Summary
Background In transitioning from the Millennium Development Goal to the Sustainable Devel... more Summary
Background In transitioning from the Millennium Development Goal to the Sustainable Development Goal era, it is
imperative to comprehensively assess progress toward reducing maternal mortality to identify areas of success,
remaining challenges, and frame policy discussions. We aimed to quantify maternal mortality throughout the world
by underlying cause and age from 1990 to 2015.
Methods We estimated maternal mortality at the global, regional, and national levels from 1990 to 2015 for ages
10–54 years by systematically compiling and processing all available data sources from 186 of 195 countries and
territories, 11 of which were analysed at the subnational level. We quantifi ed eight underlying causes of maternal
death and four timing categories, improving estimation methods since GBD 2013 for adult all-cause mortality, HIVrelated
maternal mortality, and late maternal death. Secondary analyses then allowed systematic examination of
drivers of trends, including the relation between maternal mortality and coverage of specifi c reproductive health-care
services as well as assessment of observed versus expected maternal mortality as a function of Socio-demographic
Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility.
Findings Only ten countries achieved MDG 5, but 122 of 195 countries have already met SDG 3.1. Geographical
disparities widened between 1990 and 2015 and, in 2015, 24 countries still had a maternal mortality ratio greater than
400. The proportion of all maternal deaths occurring in the bottom two SDI quintiles, where haemorrhage is the
dominant cause of maternal death, increased from roughly 68% in 1990 to more than 80% in 2015. The middle SDI
quintile improved the most from 1990 to 2015, but also has the most complicated causal profi le. Maternal mortality in
the highest SDI quintile is mostly due to other direct maternal disorders, indirect maternal disorders, and abortion,
ectopic pregnancy, and/or miscarriage. Historical patterns suggest achievement of SDG 3.1 will require 91% coverage
of one antenatal care visit, 78% of four antenatal care visits, 81% of in-facility delivery, and 87% of skilled
birth attendance.
Interpretation Several challenges to improving reproductive health lie ahead in the SDG era. Countries should
establish or renew systems for collection and timely dissemination of health data; expand coverage and improve
quality of family planning services, including access to contraception and safe abortion to address high adolescent
fertility; invest in improving health system capacity, including coverage of routine reproductive health care and of
more advanced obstetric care—including EmOC; adapt health systems and data collection systems to monitor and
reverse the increase in indirect, other direct, and late maternal deaths, especially in high SDI locations; and examine
their own performance with respect to their SDI level, using that information to formulate strategies to improve
performance and ensure optimum reproductive health of their population.
Background Timely assessment of the burden of HIV/AIDS is essential for policy setting and progra... more Background Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluation. In this report from the Global Burden of Disease Study 2015 (GBD 2015), we provide national estimates of levels and trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries and territories from 1980 to 2015.
BACKGROUND: Timely assessment of the burden of HIV/AIDS is essential for policy setting and progr... more BACKGROUND: Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluation. In this report from the Global Burden of Disease Study 2015 (GBD 2015), we provide national estimates of levels and trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries and territories from 1980 to 2015.
METHODS: For countries without high-quality vital registration data, we estimated prevalence and incidence with data from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4 cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes. Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS (UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for garbage coding and HIV misclassification.
FINDINGS: Global HIV incidence reached its peak in 1997, at 3·3 million new infections (95% uncertainty interval [UI] 3·1-3·4 million). Annual incidence has stayed relatively constant at about 2·6 million per year (range 2·5-2·8 million) since 2005, after a period of fast decline between 1997 and 2005. The number of people living with HIV/AIDS has been steadily increasing and reached 38·8 million (95% UI 37·6-40·4 million) in 2015. At the same time, HIV/AIDS mortality has been declining at a steady pace, from a peak of 1·8 million deaths (95% UI 1·7-1·9 million) in 2005, to 1·2 million deaths (1·1-1·3 million) in 2015. We recorded substantial heterogeneity in the levels and trends of HIV/AIDS across countries. Although many countries have experienced decreases in HIV/AIDS mortality and in annual new infections, other countries have had slowdowns or increases in rates of change in annual new infections.
Academic Psychiatry, 2014
Access and adherence to medical care enable persons with HIV to live longer and healthier lives. ... more Access and adherence to medical care enable persons with HIV to live longer and healthier lives. Adherence to care improves quality of life, prevents progression to AIDS, and also has significant public health implications. Early childhood trauma-induced posttraumatic stress disorder (PTSD) is one factor that has been identified as an obstacle to adherence to both risk reduction and HIV care. The authors developed a 4-h curriculum to provide clinicians with more confidence in their ability to elicit a trauma history, diagnose PTSD, and address trauma and its sequelae in persons with HIV to improve adherence to medical care, antiretroviral medications, and risk reduction. The curriculum was designed to address the educational needs of primary care physicians, infectious disease specialists, psychiatrists, other specialists, psychologists, social workers, nurses, residents, medical students, and other trainees who provide care for persons infected with and affected by HIV.
World Allergy Organization Journal, 2007
Background: Mashhad locates in North-East of Iran and so close to the borders of Afghanistan and ... more Background: Mashhad locates in North-East of Iran and so close to the borders of Afghanistan and Turkmenistan, also considered as a migrated city due to religious reasons. Injecting Drug Users are increasing due to its lower cost and other interests especially in ...
Psychosomatics, 2013
Depression and fatigue are common in chronic hepatitis C (CHC). We report clinical predictors of ... more Depression and fatigue are common in chronic hepatitis C (CHC). We report clinical predictors of these conditions in patients seen in a university clinic. A total of 167 CHC patients completed the Patient Health Questionnaire-9 (PHQ-9) and Fatigue Severity Scale (FSS). Major depressive disorder (MDD) suggested by PHQ-9 was confirmed by clinical interview. FSS scores ≥41 were considered clinically significant fatigue. Logistic and multiple regression models were employed for analysis. Thirty-three percent of patients had MDD and 52% had clinically significant fatigue. Sixty-one percent were HIV-infected, among whom both MDD and clinically significant fatigue were significantly less prevalent (OR = 0.47 and 0.46, respectively). MDD was least common in patients without a history of IV drug use (OR = 0.28), and highest in methadone users (OR = 3.57). Compared with methadone users, patients with no history of IV drug use and former IV drug users had less severe fatigue (coefficients = -31.0, -34.0, respectively). Lack of a history of hepatitis treatment was also associated with less severe fatigue (coefficient= -7.6). Our study confirms high prevalence of fatigue and depression in CHC. HIV-positivity was associated with lower rates of MDD and clinically significant fatigue, arguably due to support systems for people living with HIV. Higher rates of depression in methadone users might be due to intrinsically higher rates of psychopathology in this group. Being on hepatitis treatment was associated with higher rates of fatigue, probably due to the adverse effects of interferon. Our findings emphasize the importance of routine screening and evaluation of depression and fatigue in CHC populations.
American Journal of Epidemiology, 2012
. Hazard ratio (HR) for mortality (squares) according to statin use in secondary-prevention obser... more . Hazard ratio (HR) for mortality (squares) according to statin use in secondary-prevention observational studies comparing prevalent users with nonusers and pooled HR for users versus nonusers (diamond). A) unadjusted results; B) adjusted results. Bars, 95% confidence interval (CI). 254 Danaei et al. Am J Epidemiol. 2012;175(4):250-262 by guest on October 16, 2016 http://aje.oxfordjournals.org/ Downloaded from Overall (I 2 = 84.2%, Leeper, 2007 (79) Muhlestein, 2004 (80) Age 80 years De Luca, 2006 (75) Allen-Maycock, 2002 (72) Age <65 years Ages 65−79 years 0.47 (0.32, 0.69) 0.81 (0.68, 0.96) 0.44 (0.29, 0.65) 0.49 (0.26, 0.93) 0.16 (0.09, 0.32) 0.52 (0.35, 0.79) 0.53 (0.38, 0.73) 0.01 0.10 1 10 100 Overall (I 2 = 57.5%, Allen.70 (0.64, 0.78) Meta-Analysis of Observational Studies of Statins 255 Am J Epidemiol. 2012;175(4):250-262 by guest on October 16, 2016 http://aje.oxfordjournals.org/ Downloaded from P = 0.000) Figure 5. Multivariate-adjusted hazard ratio (HR) for mortality (squares) according to statin use in secondary-prevention observational studies comparing incident users with nonusers and pooled HR for users versus nonusers (diamond). Bars, 95% confidence interval (CI).
The Lancet. Global health, Jan 24, 2016
The eastern Mediterranean region is comprised of 22 countries: Afghanistan, Bahrain, Djibouti, Eg... more The eastern Mediterranean region is comprised of 22 countries: Afghanistan, Bahrain, Djibouti, Egypt, Iran, Iraq, Jordan, Kuwait, Lebanon, Libya, Morocco, Oman, Pakistan, Palestine, Qatar, Saudi Arabia, Somalia, Sudan, Syria, Tunisia, the United Arab Emirates, and Yemen. Since our Global Burden of Disease Study 2010 (GBD 2010), the region has faced unrest as a result of revolutions, wars, and the so-called Arab uprisings. The objective of this study was to present the burden of diseases, injuries, and risk factors in the eastern Mediterranean region as of 2013. GBD 2013 includes an annual assessment covering 188 countries from 1990 to 2013. The study covers 306 diseases and injuries, 1233 sequelae, and 79 risk factors. Our GBD 2013 analyses included the addition of new data through updated systematic reviews and through the contribution of unpublished data sources from collaborators, an updated version of modelling software, and several improvements in our methods. In this systemati...
The Lancet HIV, 2016
Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluat... more Timely assessment of the burden of HIV/AIDS is essential for policy setting and programme evaluation. In this report from the Global Burden of Disease Study 2015 (GBD 2015), we provide national estimates of levels and trends of HIV/AIDS incidence, prevalence, coverage of antiretroviral therapy (ART), and mortality for 195 countries and territories from 1980 to 2015. For countries without high-quality vital registration data, we estimated prevalence and incidence with data from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4 cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes. Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS (UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for garbage coding and HIV misclassification. Global HIV incidence reached its peak in 1997, at 3·3 million new infections (95% uncertainty interval [UI] 3·1-3·4 million). Annual incidence has stayed relatively constant at about 2·6 million per year (range 2·5-2·8 million) since 2005, after a period of fast decline between 1997 and 2005. The number of people living with HIV/AIDS has been steadily increasing and reached 38·8 million (95% UI 37·6-40·4 million) in 2015. At the same time, HIV/AIDS mortality has been declining at a steady pace, from a peak of 1·8 million deaths (95% UI 1·7-1·9 million) in 2005, to 1·2 million deaths (1·1-1·3 million) in 2015. We recorded substantial heterogeneity in the levels and trends of HIV/AIDS across countries. Although many countries have experienced decreases in HIV/AIDS mortality and in annual new infections, other countries have had slowdowns or increases in rates of change in annual new infections. Scale-up of ART and prevention of mother-to-child transmission has been one of the great successes of global health in the past two decades. However, in the past decade, progress in reducing new infections has been slow, development assistance for health devoted to HIV has stagnated, and resources for health in low-income countries have grown slowly. Achievement of the new ambitious goals for HIV enshrined in Sustainable Development Goal 3 and the 90-90-90 UNAIDS targets will be challenging, and will need continued efforts from governments and international agencies in the next 15 years to end AIDS by 2030. Bill…
The Lancet, 2015
Background The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all availabl... more Background The Global Burden of Disease Study 2013 (GBD 2013) aims to bring together all available epidemiological data using a coherent measurement framework, standardised estimation methods, and transparent data sources to enable comparisons of health loss over time and across causes, age-sex groups, and countries. The GBD can be used to generate summary measures such as disability-adjusted life-years (DALYs) and healthy life expectancy (HALE) that make possible comparative assessments of broad epidemiological patterns across countries and time. These summary measures can also be used to quantify the component of variation in epidemiology that is related to sociodemographic development.
The Lancet, 2012
Measuring disease and injury burden in populations requires a composite metric that captures both... more Measuring disease and injury burden in populations requires a composite metric that captures both premature mortality and the prevalence and severity of ill-health. The 1990 Global Burden of Disease study proposed disability-adjusted life years (DALYs) to measure disease burden. No comprehensive update of disease burden worldwide incorporating a systematic reassessment of disease and injury-specific epidemiology has been done since the 1990 study. We aimed to calculate disease burden worldwide and for 21 regions for 1990, 2005, and 2010 with methods to enable meaningful comparisons over time. We calculated DALYs as the sum of years of life lost (YLLs) and years lived with disability (YLDs). DALYs were calculated for 291 causes, 20 age groups, both sexes, and for 187 countries, and aggregated to regional and global estimates of disease burden for three points in time with strictly comparable definitions and methods. YLLs were calculated from age-sex-country-time-specific estimates of mortality by cause, with death by standardised lost life expectancy at each age. YLDs were calculated as prevalence of 1160 disabling sequelae, by age, sex, and cause, and weighted by new disability weights for each health state. Neither YLLs nor YLDs were age-weighted or discounted. Uncertainty around cause-specific DALYs was calculated incorporating uncertainty in levels of all-cause mortality, cause-specific mortality, prevalence, and disability weights. Global DALYs remained stable from 1990 (2·503 billion) to 2010 (2·490 billion). Crude DALYs per 1000 decreased by 23% (472 per 1000 to 361 per 1000). An important shift has occurred in DALY composition with the contribution of deaths and disability among children (younger than 5 years of age) declining from 41% of global DALYs in 1990 to 25% in 2010. YLLs typically account for about half of disease burden in more developed regions (high-income Asia Pacific, western Europe, high-income North America, and Australasia), rising to over 80% of DALYs in sub-Saharan Africa. In 1990, 47% of DALYs worldwide were from communicable, maternal, neonatal, and nutritional disorders, 43% from non-communicable diseases, and 10% from injuries. By 2010, this had shifted to 35%, 54%, and 11%, respectively. Ischaemic heart disease was the leading cause of DALYs worldwide in 2010 (up from fourth rank in 1990, increasing by 29%), followed by lower respiratory infections (top rank in 1990; 44% decline in DALYs), stroke (fifth in 1990; 19% increase), diarrhoeal diseases (second in 1990; 51% decrease), and HIV/AIDS (33rd in 1990; 351% increase). Major depressive disorder increased from 15th to 11th rank (37% increase) and road injury from 12th to 10th rank (34% increase). Substantial heterogeneity exists in rankings of leading causes of disease burden among regions. Global disease burden has continued to shift away from communicable to non-communicable diseases and from premature death to years lived with disability. In sub-Saharan Africa, however, many communicable, maternal, neonatal, and nutritional disorders remain the dominant causes of disease burden. The rising burden from mental and behavioural disorders, musculoskeletal disorders, and diabetes will impose new challenges on health systems. Regional heterogeneity highlights the importance of understanding local burden of disease and setting goals and targets for the post-2015 agenda taking such patterns into account. Because of improved definitions, methods, and data, these results for 1990 and 2010 supersede all previously published Global Burden of Disease results. Bill…
The Lancet, 2012
Non-fatal health outcomes from diseases and injuries are a crucial consideration in the promotion... more 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…
JAMA, 2013
Understanding the major health problems in the United States and how they are changing over time ... more Understanding the major health problems in the United States and how they are changing over time is critical for informing national health policy. To measure the burden of diseases, injuries, and leading risk factors in the United States from 1990 to 2010 and to compare these measurements with those of the 34 countries in the Organisation for Economic Co-operation and Development (OECD) countries. We used the systematic analysis of descriptive epidemiology of 291 diseases and injuries, 1160 sequelae of these diseases and injuries, and 67 risk factors or clusters of risk factors from 1990 to 2010 for 187 countries developed for the Global Burden of Disease 2010 Study to describe the health status of the United States and to compare US health outcomes with those of 34 OECD countries. Years of life lost due to premature mortality (YLLs) were computed by multiplying the number of deaths at each age by a reference life expectancy at that age. Years lived with disability (YLDs) were calculated by multiplying prevalence (based on systematic reviews) by the disability weight (based on population-based surveys) for each sequela; disability in this study refers to any short- or long-term loss of health. Disability-adjusted life-years (DALYs) were estimated as the sum of YLDs and YLLs. Deaths and DALYs related to risk factors were based on systematic reviews and meta-analyses of exposure data and relative risks for risk-outcome pairs. Healthy life expectancy (HALE) was used to summarize overall population health, accounting for both length of life and levels of ill health experienced at different ages. US life expectancy for both sexes combined increased from 75.2 years in 1990 to 78.2 years in 2010; during the same period, HALE increased from 65.8 years to 68.1 years. The diseases and injuries with the largest number of YLLs in 2010 were ischemic heart disease, lung cancer, stroke, chronic obstructive pulmonary disease, and road injury. Age-standardized YLL rates increased for Alzheimer disease, drug use disorders, chronic kidney disease, kidney cancer, and falls. The diseases with the largest number of YLDs in 2010 were low back pain, major depressive disorder, other musculoskeletal disorders, neck pain, and anxiety disorders. As the US population has aged, YLDs have comprised a larger share of DALYs than have YLLs. The leading risk factors related to DALYs were dietary risks, tobacco smoking, high body mass index, high blood pressure, high fasting plasma glucose, physical inactivity, and alcohol use. Among 34 OECD countries between 1990 and 2010, the US rank for the age-standardized death rate changed from 18th to 27th, for the age-standardized YLL rate from 23rd to 28th, for the age-standardized YLD rate from 5th to 6th, for life expectancy at birth from 20th to 27th, and for HALE from 14th to 26th. From 1990 to 2010, the United States made substantial progress in improving health. Life expectancy at birth and HALE increased, all-cause death rates at all ages decreased, and age-specific rates of years lived with disability remained stable. However, morbidity and chronic disability now account for nearly half of the US health burden, and improvements in population health in the United States have not kept pace with advances in population health in other wealthy nations.
Lancet (London, England), Jan 10, 2015
The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a s... more The Global Burden of Disease, Injuries, and Risk Factor study 2013 (GBD 2013) is the first of a series of annual updates of the GBD. Risk factor quantification, particularly of modifiable risk factors, can help to identify emerging threats to population health and opportunities for prevention. The GBD 2013 provides a timely opportunity to update the comparative risk assessment with new data for exposure, relative risks, and evidence on the appropriate counterfactual risk distribution. Attributable deaths, years of life lost, years lived with disability, and disability-adjusted life-years (DALYs) have been estimated for 79 risks or clusters of risks using the GBD 2010 methods. Risk-outcome pairs meeting explicit evidence criteria were assessed for 188 countries for the period 1990-2013 by age and sex using three inputs: risk exposure, relative risks, and the theoretical minimum risk exposure level (TMREL). Risks are organised into a hierarchy with blocks of behavioural, environmental...
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Papers by Mohammad Tavakkoli
Background In transitioning from the Millennium Development Goal to the Sustainable Development Goal era, it is
imperative to comprehensively assess progress toward reducing maternal mortality to identify areas of success,
remaining challenges, and frame policy discussions. We aimed to quantify maternal mortality throughout the world
by underlying cause and age from 1990 to 2015.
Methods We estimated maternal mortality at the global, regional, and national levels from 1990 to 2015 for ages
10–54 years by systematically compiling and processing all available data sources from 186 of 195 countries and
territories, 11 of which were analysed at the subnational level. We quantifi ed eight underlying causes of maternal
death and four timing categories, improving estimation methods since GBD 2013 for adult all-cause mortality, HIVrelated
maternal mortality, and late maternal death. Secondary analyses then allowed systematic examination of
drivers of trends, including the relation between maternal mortality and coverage of specifi c reproductive health-care
services as well as assessment of observed versus expected maternal mortality as a function of Socio-demographic
Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility.
Findings Only ten countries achieved MDG 5, but 122 of 195 countries have already met SDG 3.1. Geographical
disparities widened between 1990 and 2015 and, in 2015, 24 countries still had a maternal mortality ratio greater than
400. The proportion of all maternal deaths occurring in the bottom two SDI quintiles, where haemorrhage is the
dominant cause of maternal death, increased from roughly 68% in 1990 to more than 80% in 2015. The middle SDI
quintile improved the most from 1990 to 2015, but also has the most complicated causal profi le. Maternal mortality in
the highest SDI quintile is mostly due to other direct maternal disorders, indirect maternal disorders, and abortion,
ectopic pregnancy, and/or miscarriage. Historical patterns suggest achievement of SDG 3.1 will require 91% coverage
of one antenatal care visit, 78% of four antenatal care visits, 81% of in-facility delivery, and 87% of skilled
birth attendance.
Interpretation Several challenges to improving reproductive health lie ahead in the SDG era. Countries should
establish or renew systems for collection and timely dissemination of health data; expand coverage and improve
quality of family planning services, including access to contraception and safe abortion to address high adolescent
fertility; invest in improving health system capacity, including coverage of routine reproductive health care and of
more advanced obstetric care—including EmOC; adapt health systems and data collection systems to monitor and
reverse the increase in indirect, other direct, and late maternal deaths, especially in high SDI locations; and examine
their own performance with respect to their SDI level, using that information to formulate strategies to improve
performance and ensure optimum reproductive health of their population.
METHODS: For countries without high-quality vital registration data, we estimated prevalence and incidence with data from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4 cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes. Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS (UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for garbage coding and HIV misclassification.
FINDINGS: Global HIV incidence reached its peak in 1997, at 3·3 million new infections (95% uncertainty interval [UI] 3·1-3·4 million). Annual incidence has stayed relatively constant at about 2·6 million per year (range 2·5-2·8 million) since 2005, after a period of fast decline between 1997 and 2005. The number of people living with HIV/AIDS has been steadily increasing and reached 38·8 million (95% UI 37·6-40·4 million) in 2015. At the same time, HIV/AIDS mortality has been declining at a steady pace, from a peak of 1·8 million deaths (95% UI 1·7-1·9 million) in 2005, to 1·2 million deaths (1·1-1·3 million) in 2015. We recorded substantial heterogeneity in the levels and trends of HIV/AIDS across countries. Although many countries have experienced decreases in HIV/AIDS mortality and in annual new infections, other countries have had slowdowns or increases in rates of change in annual new infections.
Background In transitioning from the Millennium Development Goal to the Sustainable Development Goal era, it is
imperative to comprehensively assess progress toward reducing maternal mortality to identify areas of success,
remaining challenges, and frame policy discussions. We aimed to quantify maternal mortality throughout the world
by underlying cause and age from 1990 to 2015.
Methods We estimated maternal mortality at the global, regional, and national levels from 1990 to 2015 for ages
10–54 years by systematically compiling and processing all available data sources from 186 of 195 countries and
territories, 11 of which were analysed at the subnational level. We quantifi ed eight underlying causes of maternal
death and four timing categories, improving estimation methods since GBD 2013 for adult all-cause mortality, HIVrelated
maternal mortality, and late maternal death. Secondary analyses then allowed systematic examination of
drivers of trends, including the relation between maternal mortality and coverage of specifi c reproductive health-care
services as well as assessment of observed versus expected maternal mortality as a function of Socio-demographic
Index (SDI), a summary indicator derived from measures of income per capita, educational attainment, and fertility.
Findings Only ten countries achieved MDG 5, but 122 of 195 countries have already met SDG 3.1. Geographical
disparities widened between 1990 and 2015 and, in 2015, 24 countries still had a maternal mortality ratio greater than
400. The proportion of all maternal deaths occurring in the bottom two SDI quintiles, where haemorrhage is the
dominant cause of maternal death, increased from roughly 68% in 1990 to more than 80% in 2015. The middle SDI
quintile improved the most from 1990 to 2015, but also has the most complicated causal profi le. Maternal mortality in
the highest SDI quintile is mostly due to other direct maternal disorders, indirect maternal disorders, and abortion,
ectopic pregnancy, and/or miscarriage. Historical patterns suggest achievement of SDG 3.1 will require 91% coverage
of one antenatal care visit, 78% of four antenatal care visits, 81% of in-facility delivery, and 87% of skilled
birth attendance.
Interpretation Several challenges to improving reproductive health lie ahead in the SDG era. Countries should
establish or renew systems for collection and timely dissemination of health data; expand coverage and improve
quality of family planning services, including access to contraception and safe abortion to address high adolescent
fertility; invest in improving health system capacity, including coverage of routine reproductive health care and of
more advanced obstetric care—including EmOC; adapt health systems and data collection systems to monitor and
reverse the increase in indirect, other direct, and late maternal deaths, especially in high SDI locations; and examine
their own performance with respect to their SDI level, using that information to formulate strategies to improve
performance and ensure optimum reproductive health of their population.
METHODS: For countries without high-quality vital registration data, we estimated prevalence and incidence with data from antenatal care clinics and population-based seroprevalence surveys, and with assumptions by age and sex on initial CD4 distribution at infection, CD4 progression rates (probability of progression from higher to lower CD4 cell-count category), on and off antiretroviral therapy (ART) mortality, and mortality from all other causes. Our estimation strategy links the GBD 2015 assessment of all-cause mortality and estimation of incidence and prevalence so that for each draw from the uncertainty distribution all assumptions used in each step are internally consistent. We estimated incidence, prevalence, and death with GBD versions of the Estimation and Projection Package (EPP) and Spectrum software originally developed by the Joint United Nations Programme on HIV/AIDS (UNAIDS). We used an open-source version of EPP and recoded Spectrum for speed, and used updated assumptions from systematic reviews of the literature and GBD demographic data. For countries with high-quality vital registration data, we developed the cohort incidence bias adjustment model to estimate HIV incidence and prevalence largely from the number of deaths caused by HIV recorded in cause-of-death statistics. We corrected these statistics for garbage coding and HIV misclassification.
FINDINGS: Global HIV incidence reached its peak in 1997, at 3·3 million new infections (95% uncertainty interval [UI] 3·1-3·4 million). Annual incidence has stayed relatively constant at about 2·6 million per year (range 2·5-2·8 million) since 2005, after a period of fast decline between 1997 and 2005. The number of people living with HIV/AIDS has been steadily increasing and reached 38·8 million (95% UI 37·6-40·4 million) in 2015. At the same time, HIV/AIDS mortality has been declining at a steady pace, from a peak of 1·8 million deaths (95% UI 1·7-1·9 million) in 2005, to 1·2 million deaths (1·1-1·3 million) in 2015. We recorded substantial heterogeneity in the levels and trends of HIV/AIDS across countries. Although many countries have experienced decreases in HIV/AIDS mortality and in annual new infections, other countries have had slowdowns or increases in rates of change in annual new infections.