Population projections for sub-Saharan Africa have, over the past decade, been corrected upwards because in a number of countries, the earlier declining trends in fertility stalled around 2000. While most studies so far have focused on economic, political, or other factors around 2000, here we suggest that in addition to those period effects, the phenomenon also matched up with disruptions in the cohort trends of educational attainment of women after the postindependence economic and political turmoil. Disruptions likely resulted in a higher proportion of poorly educated women of childbearing age in the late 1990s and early 2000s than there would have been otherwise. In addition to the direct effects of education on lowering fertility, these less-educated female cohorts were also more vulnerable to adverse period effects around 2000. To explore this hypothesis, we combine individual-level data from Demographic and Health Surveys for 18 African countries with and without fertility stalls, thus creating a pooled dataset of more than two million births to some 670,000 women born from 1950 to 1995 by level of education. Statistical analyses indicate clear discontinuities in the improvement of educational attainment of subsequent cohorts of women and stronger sensitivity of less-educated women to period effects. We assess the magnitude of the effect of educational discontinuity through a comparison of the actual trends with counterfactual trends based on the assumption of no education stalls, resulting in up to half a child per woman less in 2010 and 13 million fewer live births over the 1995–2010 period.
Population projections for sub-Saharan Africa have, over the past decade, been corrected upwards because in a number of countries, the earlier declining trends in fertility stalled around 2000. While most studies so far have focused on economic, political, or other factors around 2000, here we suggest that in addition to those period effects, the phenomenon also matched up with disruptions in the cohort trends of educational attainment of women after the postindependence economic and political turmoil. Disruptions likely resulted in a higher proportion of poorly educated women of childbearing age in the late 1990s and early 2000s than there would have been otherwise. In addition to the direct effects of education on lowering fertility, these less-educated female cohorts were also more vulnerable to adverse period effects around 2000. To explore this hypothesis, we combine individual-level data from Demographic and Health Surveys for 18 African countries with and without fertility stalls, thus creating a pooled dataset of more than two million births to some 670,000 women born from 1950 to 1995 by level of education. Statistical analyses indicate clear discontinuities in the improvement of educational attainment of subsequent cohorts of women and stronger sensitivity of less-educated women to period effects. We assess the magnitude of the effect of educational discontinuity through a comparison of the actual trends with counterfactual trends based on the assumption of no education stalls, resulting in up to half a child per woman less in 2010 and 13 million fewer live births over the 1995–2010 period.
BACKGROUND Despite an increase in scholarly and policy interest regarding the impacts of environmental change on migration, empirical knowledge in the field remains varied, patchy, and limited. Generalised discourse on environmental migration frequently oversimplifies the complex channels through which environmental change influences the migration process. OBJECTIVE This paper aims to systematise the existing empirical evidence on migration influenced by environmental change with a focus on Africa, the continent most vulnerable to climate change. METHODS We select 53 qualitative and quantitative studies on the influence of environmental change on migration from the comprehensive Climig database and systematically analyse the literature considering the multidimensional drivers of migration. RESULTS Environmental change influences migration in Africa in an indirect way by affecting other drivers of migration, including sociodemographic, economic, and political factors. How and in what direction environmental change influences migration depends on socioeconomic and geographical contexts, demographic characteristics, and the type and duration of migration. CONCLUSIONS The contextually contingent nature of migration–environment relationships prevents us from drawing a universal conclusion, whether environmental change will increase or suppress migration in Africa. However, this study unravels the complex interactions between the nature and duration of the environmental pressure, the livelihood of the populations, the role of kinship ties and the role of demographic differentials on migration response. CONTRIBUTION The review provides an initial systematic and comprehensive summary of empirical evidence on the environmental drivers of migration in Africa. It also discusses the implications of the scale, materials, and methods used in the 53 studies.
BACKGROUND Despite an increase in scholarly and policy interest regarding the impacts of environmental change on migration, empirical knowledge in the field remains varied, patchy, and limited. Generalised discourse on environmental migration frequently oversimplifies the complex channels through which environmental change influences the migration process. OBJECTIVE This paper aims to systematise the existing empirical evidence on migration influenced by environmental change with a focus on Africa, the continent most vulnerable to climate change. METHODS We select 53 qualitative and quantitative studies on the influence of environmental change on migration from the comprehensive Climig database and systematically analyse the literature considering the multidimensional drivers of migration. RESULTS Environmental change influences migration in Africa in an indirect way by affecting other drivers of migration, including sociodemographic, economic, and political factors. How and in what direction environmental change influences migration depends on socioeconomic and geographical contexts, demographic characteristics, and the type and duration of migration. CONCLUSIONS The contextually contingent nature of migration–environment relationships prevents us from drawing a universal conclusion, whether environmental change will increase or suppress migration in Africa. However, this study unravels the complex interactions between the nature and duration of the environmental pressure, the livelihood of the populations, the role of kinship ties and the role of demographic differentials on migration response. CONTRIBUTION The review provides an initial systematic and comprehensive summary of empirical evidence on the environmental drivers of migration in Africa. It also discusses the implications of the scale, materials, and methods used in the 53 studies.
BACKGROUND Despite an increase in scholarly and policy interests in the impacts of environmental and climate change on migration, empirical knowledge in the field remains varied, patchy and limited. Generalized discourse on migration influenced by environmental change frequently leads to an oversimplification of the complex channels through which environmental change influences the migration process. The role of environmental and climate change in driving migration reported in existing studies seems to vary from one extreme to the other ‒ from limited and rather indirect role to significant impacts ‒ preventing us from drawing a conclusive evidence. OBJECTIVE This paper seeks to systematize the existing empirical evidence on migration influenced by environmental change with a focus on Africa, the continent most vulnerable to climate change. METHODS We combine elements of a systematic evidence assessment with a more reflexive form of evidence-focused literature review. 53 qualitative and quantitative studies selected from the comprehensive "Climig database" on the influence of environmental change on migration are systematically analyzed based on the framework of the multi-dimensional drivers of migration. RESULTS Environmental change influences migration in Africa in an indirect way i.e. through affecting other drivers of migration including sociodemographic, economic and political factors. How and in what direction environmental change influences migration depends on socioeconomic and geographical contexts, demographic characteristics and type and duration of migration. CONCLUSIONS It is not possible to draw a universal conclusion whether environmental change will increase or suppress migration in Africa since it is context-specific. CONTRIBUTION The review provides a first systematic and comprehensive summary of empirical evidence on environmental driver of migration in Africa considering direct and indirect pathways through which environmental change influence internal and international migration.
BACKGROUND Despite an increase in scholarly and policy interests in the impacts of environmental and climate change on migration, empirical knowledge in the field remains varied, patchy and limited. Generalized discourse on migration influenced by environmental change frequently leads to an oversimplification of the complex channels through which environmental change influences the migration process. The role of environmental and climate change in driving migration reported in existing studies seems to vary from one extreme to the other ‒ from limited and rather indirect role to significant impacts ‒ preventing us from drawing a conclusive evidence. OBJECTIVE This paper seeks to systematize the existing empirical evidence on migration influenced by environmental change with a focus on Africa, the continent most vulnerable to climate change. METHODS We combine elements of a systematic evidence assessment with a more reflexive form of evidence-focused literature review. 53 qualitative and quantitative studies selected from the comprehensive "Climig database" on the influence of environmental change on migration are systematically analyzed based on the framework of the multi-dimensional drivers of migration. RESULTS Environmental change influences migration in Africa in an indirect way i.e. through affecting other drivers of migration including sociodemographic, economic and political factors. How and in what direction environmental change influences migration depends on socioeconomic and geographical contexts, demographic characteristics and type and duration of migration. CONCLUSIONS It is not possible to draw a universal conclusion whether environmental change will increase or suppress migration in Africa since it is context-specific. CONTRIBUTION The review provides a first systematic and comprehensive summary of empirical evidence on environmental driver of migration in Africa considering direct and indirect pathways through which environmental change influence internal and international migration.
Malaria intervention in Ethiopia has been strengthened significantly in the past decade. The Ethiopian government recently stratified the country based upon annual parasite incidence into malaria free, low, moderate and high transmission strata. Districts with low transmission were targeted for indigenous transmission elimination. Surveillance on malaria disease incidence is needed for planning control and elimination efforts.Clinical malaria was monitored prospectively in health facilities in Jimma town, Oromia Region, southwestern Ethiopia from July 2014 to June 2015. Seasonal cross-sectional parasite prevalence surveys in local communities were conducted in 2014 and 2015 in eight kebeles. Case report forms were administered to obtain sociodemographic and epidemiological information from patients.A total of 1434 suspected malaria cases were examined from the health facilities and 428 confirmed malaria cases were found. Among them, 327 (76.4 %) cases were Plasmodium vivax, 97 (22.7 %) were Plasmodium falciparum, and 4 (0.9 %) were mixed infection of P. vivax and P. falciparum. The annual malaria incidence rate was 1.7 cases per 1000 people at risk. Parasite prevalence in the community was less than 3 %. Household ownership of insecticide-treated nets (ITNs) was 47.3 % (1173/2479) and ITN usage was 37.9 %. All ITNs were long-lasting insecticidal nets, and repellent use was not found in the study area. Being male and traveling were the significant risk factors for P. falciparum malaria. For P. vivax malaria, risk factors included occupation and history of malaria illness during the preceding 30 days.Epidemiological evidence suggested low clinical malaria incidence and prevalence in Jimma town. More aggressive measures may be needed to further suppress vivax transmission. Strategies should be planned targeting sustained control and elimination.
Background: Neurological disorders are increasingly recognised as major causes of death and disability worldwide. The aim of this analysis from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2016 is to provide the most comprehensive and up-to-date estimates of the global, regional, and national burden from neurological disorders. Methods: We estimated prevalence, incidence, deaths, and disability-adjusted life-years (DALYs; the sum of years of life lost [YLLs] and years lived with disability [YLDs]) by age and sex for 15 neurological disorder categories (tetanus, meningitis, encephalitis, stroke, brain and other CNS cancers, traumatic brain injury, spinal cord injury, Alzheimer's disease and other dementias, Parkinson's disease, multiple sclerosis, motor neuron diseases, idiopathic epilepsy, migraine, tension-type headache, and a residual category for other less common neurological disorders) in 195 countries from 1990 to 2016. DisMod-MR 2.1, a Bayesian meta-regression tool, was the main method of estimation of prevalence and incidence, and the Cause of Death Ensemble model (CODEm) was used for mortality estimation. We quantified the contribution of 84 risks and combinations of risk to the disease estimates for the 15 neurological disorder categories using the GBD comparative risk assessment approach. Findings: Globally, in 2016, neurological disorders were the leading cause of DALYs (276 million [95% UI 247–308]) and second leading cause of deaths (9·0 million [8·8–9·4]). The absolute number of deaths and DALYs from all neurological disorders combined increased (deaths by 39% [34–44] and DALYs by 15% [9–21]) whereas their age-standardised rates decreased (deaths by 28% [26–30] and DALYs by 27% [24–31]) between 1990 and 2016. The only neurological disorders that had a decrease in rates and absolute numbers of deaths and DALYs were tetanus, meningitis, and encephalitis. The four largest contributors of neurological DALYs were stroke (42·2% [38·6–46·1]), migraine (16·3% [11·7–20·8]), Alzheimer's and other dementias (10·4% [9·0–12·1]), and meningitis (7·9% [6·6–10·4]). For the combined neurological disorders, age-standardised DALY rates were significantly higher in males than in females (male-to-female ratio 1·12 [1·05–1·20]), but migraine, multiple sclerosis, and tension-type headache were more common and caused more burden in females, with male-to-female ratios of less than 0·7. The 84 risks quantified in GBD explain less than 10% of neurological disorder DALY burdens, except stroke, for which 88·8% (86·5–90·9) of DALYs are attributable to risk factors, and to a lesser extent Alzheimer's disease and other dementias (22·3% [11·8–35·1] of DALYs are risk attributable) and idiopathic epilepsy (14·1% [10·8–17·5] of DALYs are risk attributable). Interpretation: Globally, the burden of neurological disorders, as measured by the absolute number of DALYs, continues to increase. As populations are growing and ageing, and the prevalence of major disabling neurological disorders steeply increases with age, governments will face increasing demand for treatment, rehabilitation, and support services for neurological disorders. The scarcity of established modifiable risks for most of the neurological burden demonstrates that new knowledge is required to develop effective prevention and treatment strategies. Funding: Bill & Melinda Gates Foundation.
Importance: Cancer and other noncommunicable diseases (NCDs) are now widely recognized as a threat to global development. The latest United Nations high-level meeting on NCDs reaffirmed this observation and also highlighted the slow progress in meeting the 2011 Political Declaration on the Prevention and Control of Noncommunicable Diseases and the third Sustainable Development Goal. Lack of situational analyses, priority setting, and budgeting have been identified as major obstacles in achieving these goals. All of these have in common that they require information on the local cancer epidemiology. The Global Burden of Disease (GBD) study is uniquely poised to provide these crucial data. Objective: To describe cancer burden for 29 cancer groups in 195 countries from 1990 through 2017 to provide data needed for cancer control planning. Evidence Review: We used the GBD study estimation methods to describe cancer incidence, mortality, years lived with disability, years of life lost, and disability-adjusted life-years (DALYs). Results are presented at the national level as well as by Socio-demographic Index (SDI), a composite indicator of income, educational attainment, and total fertility rate. We also analyzed the influence of the epidemiological vs the demographic transition on cancer incidence. Findings: In 2017, there were 24.5 million incident cancer cases worldwide (16.8 million without nonmelanoma skin cancer [NMSC]) and 9.6 million cancer deaths. The majority of cancer DALYs came from years of life lost (97%), and only 3% came from years lived with disability. The odds of developing cancer were the lowest in the low SDI quintile (1 in 7) and the highest in the high SDI quintile (1 in 2) for both sexes. In 2017, the most common incident cancers in men were NMSC (4.3 million incident cases); tracheal, bronchus, and lung (TBL) cancer (1.5 million incident cases); and prostate cancer (1.3 million incident cases). The most common causes of cancer deaths and DALYs for men were TBL cancer (1.3 million deaths and 28.4 million DALYs), liver cancer (572000 deaths and 15.2 million DALYs), and stomach cancer (542000 deaths and 12.2 million DALYs). For women in 2017, the most common incident cancers were NMSC (3.3 million incident cases), breast cancer (1.9 million incident cases), and colorectal cancer (819000 incident cases). The leading causes of cancer deaths and DALYs for women were breast cancer (601000 deaths and 17.4 million DALYs), TBL cancer (596000 deaths and 12.6 million DALYs), and colorectal cancer (414000 deaths and 8.3 million DALYs). Conclusions and Relevance: The national epidemiological profiles of cancer burden in the GBD study show large heterogeneities, which are a reflection of different exposures to risk factors, economic settings, lifestyles, and access to care and screening. The GBD study can be used by policy makers and other stakeholders to develop and improve national and local cancer control in order to achieve the global targets and improve equity in cancer care.
