| 41. |
- Byass, Peter
(författare)
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Climate change and population health in Africa : where are the scientists?
- 2009
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Ingår i: Global Health Action. - : CoAction Publishing. - 1654-9716 .- 1654-9880. ; 2, s. 173-176
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Tidskriftsartikel (refereegranskat)abstract
- Despite a growing awareness of Africans' vulnerability to climate change, there is relatively little empirical evidence published about the effects of climate on population health in Africa. This review brings together some of the generalised predictions about the potential continent-wide effects of climate change with examples of the relatively few locally documented population studies in which climate change and health interact. Although ecologically determined diseases such as malaria are obvious candidates for susceptibility to climate change, wider health effects also need to be considered, particularly among populations where adequacy of food and water supplies may already be marginal.
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| 42. |
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| 43. |
- Byass, Peter, et al.
(författare)
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Comparing verbal autopsy cause of death findings as determined by physician coding and probabilistic modelling : a public health analysis of 54 000 deaths in Africa and Asia
- 2015
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Ingår i: Journal of Global Health. - 2047-2978 .- 2047-2986. ; 5:1, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Coverage of civil registration and vital statistics varies globally, with most deaths in Africa and Asia remaining either unregistered or registered without cause of death. One important constraint has been a lack of fit-for-purpose tools for registering deaths and assigning causes in situations where no doctor is involved. Verbal autopsy (interviewing care-givers and witnesses to deaths and interpreting their information into causes of death) is the only available solution. Automated interpretation of verbal autopsy data into cause of death information is essential for rapid, consistent and affordable processing.METHODS: Verbal autopsy archives covering 54 182 deaths from five African and Asian countries were sourced on the basis of their geographical, epidemiological and methodological diversity, with existing physician-coded causes of death attributed. These data were unified into the WHO 2012 verbal autopsy standard format, and processed using the InterVA-4 model. Cause-specific mortality fractions from InterVA-4 and physician codes were calculated for each of 60 WHO 2012 cause categories, by age group, sex and source. Results from the two approaches were assessed for concordance and ratios of fractions by cause category. As an alternative metric, the Wilcoxon matched-pairs signed ranks test with two one-sided tests for stochastic equivalence was used.FINDINGS: The overall concordance correlation coefficient between InterVA-4 and physician codes was 0.83 (95% CI 0.75 to 0.91) and this increased to 0.97 (95% CI 0.96 to 0.99) when HIV/AIDS and pulmonary TB deaths were combined into a single category. Over half (53%) of the cause category ratios between InterVA-4 and physician codes by source were not significantly different from unity at the 99% level, increasing to 62% by age group. Wilcoxon tests for stochastic equivalence also demonstrated equivalence.CONCLUSIONS: These findings show strong concordance between InterVA-4 and physician-coded findings over this large and diverse data set. Although these analyses cannot prove that either approach constitutes absolute truth, there was high public health equivalence between the findings. Given the urgent need for adequate cause of death data from settings where deaths currently pass unregistered, and since the WHO 2012 verbal autopsy standard and InterVA-4 tools represent relatively simple, cheap and available methods for determining cause of death on a large scale, they should be used as current tools of choice to fill gaps in cause of death data.
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| 44. |
- Byass, Peter
(författare)
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Correlation between noncommunicable disease mortality in people aged 30-69 years and those aged 70-89 years
- 2019
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Ingår i: Bulletin of the World Health Organization. - : WORLD HEALTH ORGANIZATION. - 0042-9686 .- 1564-0604. ; 97:9, s. 589-596
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Tidskriftsartikel (refereegranskat)abstract
- Objective: To investigate whether the key metric for monitoring progress towards sustainable development goal target 3.4 that is measuring premature noncommunicable disease mortality (deaths among people aged 30-69 years), is ageist.Methods: To examine the relationship between premature noncommunicable disease mortality and noncommunicable disease mortality in older people, a database of mortality rates for cardiovascular disease, cancer, chronic obstructive pulmonary disease and diabetes in people aged 30 to 69 years and 70 to 89 years was compiled using estimates from the Global Burden of Disease Study 2017. The data covered 195 countries, six time-points and both sexes, giving 2340 instances. The World Health Organization's (WHO's) life-table method for the premature noncommunicable disease mortality metric was applied to the data.Findings: There was a strong correlation between noncommunicable disease mortality patterns in the premature and older age groups, which suggests that measuring premature noncommunicable disease mortality is informative about such mortality in later life. Neither time nor geographical location had a substantial effect on this correlation. However, there were female-to-male differences in age-specific probabilities of death due to noncommunicable disease, implying that noncommunicable disease mortality should be assessed using a sex-disaggregated approach.Conclusion: As the established WHO metric for premature noncommunicable disease mortality was predictive of noncommunicable disease mortality in older people, the metric should not be construed as ageist Focusing resources on measuring premature noncommunicable disease mortality will be appropriate, particularly in settings without universal civil death registration. This approach should not prejudice the provision of health services throughout the life-course.
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| 45. |
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| 46. |
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| 47. |
- Byass, Peter, et al.
(författare)
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DSS and DHS : longitudinal and cross-sectional viewpoints on child and adolescent mortality in Ethiopia
- 2007
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Ingår i: Population Health Metrics. - : BioMed Central (BMC). - 1478-7954. ; 5:1, s. Article nr 12-
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: In countries where routine vital registration data are scarce, Demographic Surveillance Sites (DSS: locally defined populations under longitudinal surveillance for vital events and other characteristics) and Demographic and Health Surveys (DHS: periodic national cluster samples responding to cross-sectional surveys) have become standard approaches for gathering at least some data. This paper aims to compare DSS and DHS approaches, seeing how they complement each other in the specific instance of child and adolescent mortality in Ethiopia.METHODS: Data from the Butajira DSS 1987-2004 and the Ethiopia DHS rounds for 2000 and 2005 formed the basis of comparative analyses of mortality rates among those aged under 20 years, using Poisson regression models for adjusted rate ratios.RESULTS: Patterns of mortality over time were broadly comparable using DSS and DHS approaches. DSS data were more susceptible to local epidemic variations, while DHS data tended to smooth out local variation, and be more subject to recall bias.CONCLUSION: Both DSS and DHS approaches to mortality surveillance gave similar overall results, but both showed method-dependent advantages and disadvantages. In many settings, this kind of joint-source data analysis could offer significant added value to results.
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| 48. |
- Byass, Peter
(författare)
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Eco-epidemiological assessment of the COVID-19 epidemic in China, January-February 2020
- 2020
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Ingår i: Global Health Action. - : Taylor & Francis. - 1654-9716 .- 1654-9880. ; 13:1, s. 1-8
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Tidskriftsartikel (refereegranskat)abstract
- Background: The outbreak of COVID-19 in China in early 2020 provides a rich data source for exploring the ecological determinants of this new infection, which may be of relevance as the pandemic develops.Objectives: Assessing the spread of the COVID-19 across China, in relation to associations between cases and ecological factors including population density, temperature, solar radiation and precipitation.Methods: Open-access COVID-19 case data include 18,069 geo-located cases in China during January and February 2020, which were mapped onto a 0.25 degrees latitude/longitude grid together with population and weather data (temperature, solar radiation and precipitation). Of 15,539 grid cells, 559 (3.6%) contained at least one case, and these were used to construct a Poisson regression model of cell-weeks. Weather parameters were taken for the preceding week given the established 5-7 day incubation period for COVID-19. The dependent variable in the Poisson model was incident cases per cell-week and exposure was cell population, allowing for clustering of cells over weeks, to give incidence rate ratios.Results: The overall COVID-19 incidence rate in cells with confirmed cases was 0.12 per 1,000. There was a single confirmed case in 113/559 (20.2%) of cells, while two grid cells recorded over 1,000 confirmed cases. Weekly means of maximum daily temperature varied from -28.0 degrees C to 30.1 degrees C, minimum daily temperature from -42.4 degrees C to 23.0 degrees C, maximum solar radiation from 0.04 to 2.74 MJm(-2) and total precipitation from 0 to 72.6 mm. Adjusted incidence rate ratios suggested brighter, warmer and drier conditions were associated with lower incidence.Conclusion: Though not demonstrating cause and effect, there were appreciable associations between weather and COVID-19 incidence during the epidemic in China. This does not mean the pandemic will go away with summer weather but demonstrates the importance of using weather conditions in understanding and forecasting the spread of COVID-19.
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| 49. |
- Byass, Peter
(författare)
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Epidemiology without borders : an anational view of global health
- 2009
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Ingår i: Global Health Action. - : CoAction Publishing. - 1654-9716 .- 1654-9880. ; 2
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Most analyses of global health use country as a unit of observation, not least because countries are intrinsic to health services and to many international organisations. However, this can mask geographical influences on population health, which do not respect political boundaries.METHODS: A global anational database was constructed with one degree cells of latitude and longitude, and used to calculate densities for population and key health indicators. These data were aggregated into 240 15 degrees ansectors, 171 of which were populated. Differences in ansector rank orders between population density and health outcomes (infant, maternal and HIV-related deaths and income) were calculated and mapped as quintiles.FINDINGS: Individual ansectors contained parts of 1-21 countries. Mapping by ansector showed that the four outcomes analysed were strongly geographically correlated. Sub-Saharan Africa was consistently disadvantaged in terms of health outcomes, while the Indian sub-continent was at an advantage in terms of HIV mortality, despite poverty.INTERPRETATION: Although in most cases it makes sense to analyse health on a national basis, these findings highlight the often unquestioned assumptions involved in doing so. Even if global patterns of health do not turn out so differently when analysed anationally, some major effects on health, such as climate change, are not nationally based, and should not necessarily be nationally analysed. Progress towards Millennium Development Goals must be evaluated on a population basis, rather than by counting countries achieving targets. Data files are available in Excel format and attached as separate files to this paper (see Supplementary files under Reading Tools online).
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| 50. |
- Byass, Peter, et al.
(författare)
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Essential evidence for guiding health system priorities and policies : anticipating epidemiological transition in Africa
- 2014
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Ingår i: Global Health Action. - : CoAction Publishing. - 1654-9716 .- 1654-9880. ; 7, s. 158-168
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND: Despite indications that infection-related mortality in sub-Saharan Africa may be decreasing and the burden of non-communicable diseases increasing, the overwhelming reality is that health information systems across most of sub-Saharan Africa remain too weak to track epidemiological transition in a meaningful and effective way.PROPOSALS: We propose a minimum dataset as the basis of a functional health information system in countries where health information is lacking. This would involve continuous monitoring of cause-specific mortality through routine civil registration, regular documentation of exposure to leading risk factors, and monitoring effective coverage of key preventive and curative interventions in the health sector. Consideration must be given as to how these minimum data requirements can be effectively integrated within national health information systems, what methods and tools are needed, and ensuring that ethical and political issues are addressed. A more strategic approach to health information systems in sub-Saharan African countries, along these lines, is essential if epidemiological changes are to be tracked effectively for the benefit of local health planners and policy makers.CONCLUSION: African countries have a unique opportunity to capitalize on modern information and communications technology in order to achieve this. Methodological standards need to be established and political momentum fostered so that the African continent's health status can be reliably tracked. This will greatly strengthen the evidence base for health policies and facilitate the effective delivery of services.
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