ARTICLE | doi:10.20944/preprints201806.0296.v1
Online: 19 June 2018 (11:13:23 CEST)
Whether evaluating gridded population dataset estimates (e.g. WorldPop, LandScan) or household survey sample designs, a population census linked to residential locations are needed. Geolocated census microdata data, however, are almost never available and are thus best simulated. In this paper, we simulate a close-to-reality population of individuals nested in households geolocated to realistic building locations. Using the R simPop package and ArcGIS, multiple realizations of a geolocated synthetic population are derived from the Namibia 2011 census 20% microdata sample, Namibia census enumeration area boundaries, Namibia 2013 Demographic and Health Survey (DHS), and dozens of publicly available spatial datasets. Realistic household latitude-longitude coordinates are manually generated based on public satellite imagery. Simulated households are linked to latitude-longitude coordinates by identifying distinct household types with multivariate kmeans analysis, and modelling a probability surface for each household type using Random Forest machine learning methods. We simulate five realizations of a synthetic population in Namibia's Oshikoto region, including demographic, socioeconomic and outcome characteristics at the level of household, woman, and child. Comparison of variables in the synthetic population were made with 2011 census 20% sample and 2013 DHS data by primary sampling unit/enumeration area. We found that synthetic population variable distributions matched observed observations and followed expected spatial patterns. We outline a novel process to simulate a close-to-reality microdata census geolocated to realistic building locations in a low- or middle-income country setting to support spatial demographic research and survey methodological development while avoiding disclosure risk of individuals.
COMMUNICATION | doi:10.20944/preprints202004.0130.v1
Online: 8 April 2020 (12:03:43 CEST)
In response to the COVID-19 pandemic, the Philippines placed the majority of the country under enhanced community quarantine, restricting the movement of most of its 100 million plus population. These aggressive measures were initiated on March 15, 2020 and intensified on March 17. According to official data, the number of confirmed COVID-19 cases has exponentially increased during this period, but it is important to note that the number of patients tested also substantially increased during the same period. It is not conclusive that widespread transmission of COVID-19 only started in March and our analysis suggests that community transmission was happening earlier. In discussing extended quarantine measures, it is important to properly understand the trends and recognize the limitations of the data. The unintended consequences on the population, especially in lower-middle income countries with fragile health systems like the Philippines, must be carefully considered.
ARTICLE | doi:10.20944/preprints202102.0492.v3
Online: 1 April 2022 (06:22:53 CEST)
Disaggregated population counts are needed to calculate health, economic, and development indicators in Low- and Middle-Income Countries (LMICs), especially in settings of rapid urbanisation. Censuses are often outdated and inaccurate in LMIC settings, and rarely disaggregated at fine geographic scale. Modelled gridded population datasets derived from census data have become widely used by development researchers and practitioners. These datasets are evaluated for accuracy at the spatial scale of the input data which is often much courser (e.g. administrative units) than the neighbourhood or cell-level scale of many applications. We simulate a realistic "true" 2016 population in Khomas, Namibia, a majority urban region, and introduce realistic levels of outdatedness (over 15 years) and inaccuracy in slum, non-slum, and rural areas. We aggregate these simulated realistic populations by census and administrative boundaries (to mimic census data), and generate 32 gridded population datasets that are typical of a LMIC setting using WorldPop-Global-Unconstrained gridded population approach. We evaluate the cell-level accuracy of these simulated datasets using the original "true" population as a reference. In our simulation, we found large cell-level errors, particularly in slum cells, driven by the use of average population densities in large areal units to determine cell-level population densities. Age, accuracy, and aggregation of the input data also played a role in these errors. We suggest incorporating finer-scale training data into gridded population models generally, and WorldPop-Global-Unconstrained in particular (e.g., from routine household surveys or slum community population counts), and use of new building footprint datasets as a covariate to improve cell-level accuracy. It is important to measure accuracy of gridded population datasets at spatial scales more consistent with how the data are being applied, especially if they are to be used for monitoring key development indicators at neighbourhood scales with relevance to small dense deprived areas within larger administrative units.
ARTICLE | doi:10.20944/preprints202107.0510.v1
Subject: Social Sciences, Accounting Keywords: LMIC; urban; deprivation; informal settlement; poverty; Global South
Online: 22 July 2021 (09:15:06 CEST)
People living in slums and other deprived areas in low- and middle-income country (LMIC) cities are under-represented in censuses, and subsequently in "top-down" gridded population estimates. Modelled gridded population data are a unique source of disaggregated population information to calculate local development indicators such as the Sustainable Development Goals (SDGs). This study evaluates if, and how, WorldPop-Global (WPG) -Unconstrained and -Constrained “top-down” datasets might be improved in a simulated realistic LMIC urban population by incorporating slum profile population counts into model training. We found that the WPG-Unconstrained model with or without slum training data grossly underestimated population in urban deprived areas while grossly overestimating population in rural areas. SDG 11.1.1, the percent of population living in slums, for example, was estimated to be 20% or less compared to a "true" value of 29.5%. The WPG-Constrained model, which included building auxiliary datasets, far more accurately estimated the population in all grid cells (including rural areas), and the inclusion of slum training data further improved estimates such that SDG 11.1.1 was estimated at 27.1% and 27.0%, respectively. Inclusion of building metrics and slum training data in “top-down” gridded population models can substantially improve grid cell-level accuracy in both urban and rural areas.
REVIEW | doi:10.20944/preprints201911.0072.v2
Subject: Social Sciences, Geography Keywords: census; survey design; household survey; LMIC; WorldPop; LandScan
Online: 19 April 2020 (08:09:23 CEST)
Objective: In low- and middle-income countries (LMICs), household survey data are a main source of information for planning, evaluation, and decision-making. Standard surveys are based on censuses, however, for many LMICs it has been more than ten years since their last census and they face high urban growth rates. Over the last decade, survey designers have begun to use modelled gridded population estimates as sample frames. We summarize the state of the emerging field of gridded population survey sampling, focussing on LMICs. Methods: We performed a systematic review and identified 43 national and sub-national gridded population-based household surveys implemented across 29 LMICs. Findings: Gridded population surveys used automated and manual approaches to derive clusters from WorldPop and LandScan gridded population estimates. After sampling, many surveys interviewed all households in each cluster or segment, though some sampled households from larger clusters. Tools to select gridded population survey clusters include the GridSample R package, Geo-sampling tool, and GridSample.org. In the field, gridded population surveys generally relied on geographically accurate maps based on satellite imagery or OpenStreetMap, and a tablet or GPS technology for navigation. Conclusions: For gridded population survey sampling to be adopted more widely, several strategic questions need answering regarding cell-level accuracy and uncertainty of gridded population estimates, the methods used to group/split cells into sample frame units, design effects of new sample designs, and feasibility of tools and methods to implement surveys across diverse settings.
COMMUNICATION | doi:10.20944/preprints202011.0629.v1
Subject: Behavioral Sciences, Applied Psychology Keywords: road safety; advanced driver assistance; safe system approach; LMIC
Online: 25 November 2020 (10:06:33 CET)
Abstract: Traffic collisions cause a huge problem of public health in low and middle income countries.. The safe system approach is generally considered as the leading concept on the way to road safety. Based on the fundamental premise that humans make mistakes, the overall traffic system should be ‘forgiving’. Sustainable safe road design is one of the key elements of the safe system approach. However, the road design principles behind the safe system approach are certainly not leading in today’s infrastructure developments in most LMICs. Cities are getting larger and road networks are expanding. In many cases, existing through-roads in local communities are up-graded, resulting in heavy traffic loads and high speeds on places, that are absolutely not suited for this kind of through-traffic. Furthermore a safe system would require that functional design properties of cars and roads would be conceptually integrated, which is not the case at all. Although advanced driver assistance systems are on their way of development for quite a long period, their potential role in the safe system concept is mostly unclear and at least strongly underexposed. The vision on future cars is dominated by the concept of automation. This paper argues that the way to self-driving cars, should take a route via the concept of guidance, i.e. vehicles that guide drivers, both on self-explaining roads and on more or less unsafe roads. Such an in-vehicle support system may help drivers to choose transport mode, route and speed, based on criteria related to safety and sustainability. It is suggested to develop a driver assistance system using relatively simple and cheap technologies, particularly for the purpose of use in LMICs. Such a GUIDE (Generic User Interface for Driving Evolution) may make roads self-explaining - not only by their physical design characteristics - but also by providing in-car guidance for drivers. In future the functional characteristics of both cars and roads should be conceptualized into one integrated safe system, in which the user plays the central role. As such GUIDE may serve as the conceptual bridge between vehicle and roadway characteristics. It is argued that GUIDE is necessary to bring a breakthrough in road safety developments in LMICs and also give an acceleration towards zero fatalities in HICs.
REVIEW | doi:10.20944/preprints202111.0454.v1
Subject: Medicine & Pharmacology, Allergology Keywords: supportive supervision; health systems strengthening; document analysis; LMIC; maternal and child health
Online: 24 November 2021 (12:45:25 CET)
Background: Supportive supervision has lately been gaining traction in various national health systems as an effective way of boosting the performance of community health workers in a constructive and sustainable way. However, not much is known about the basis/mandate of supportive supervision and its approach in maternal and child health programs in India. The current analysis contributes to a clearer understanding of the paradigms within which supportive supervision is envisioned to operate within India and identifies potential strengths and areas requiring attention. Method: Document analysis of implementation documents such as guidelines/ operational manuals/operationalization modules/ training modules of nationally implemented maternal and child health programs, with data extraction according to a pre-determined domain-based template. Results: Many of the documents reviewed do not mention supportive supervision at all. In the few documents where supportive supervision is mentioned, the paradigms within which it is supposed to operate (who will do it, when will it be done, how to do it, training and logistic support, reporting formats, etc.) have not been clearly identified in most programs. Conclusion: Even though supportive supervision is being increasingly identified as an effective way of performative improvement in national health programs in India, more effort needs to be put into identifying and enforcing the tenets of supportive supervision in practice, in order to bring about the desired change.
Subject: Medicine & Pharmacology, Nutrition Keywords: vitamin C status; hypovitaminosis C; vitamin C deficiency; low and middle income countries; LMIC; dietary intake; supplement; non-communicable disease; communicable disease; infection
Online: 24 May 2020 (18:16:25 CEST)
Vitamin C is an essential nutrient that must be obtained through the diet in adequate amounts to prevent hypovitaminosis C and the potentially fatal deficiency disease scurvy. Global vitamin C status and prevalence of deficiency has not previously been reported, despite vitamin C’s pleiotropic roles in both non-communicable and communicable disease. This review highlights the global literature on vitamin C status and the prevalence of hypovitaminosis C and deficiency. Related dietary intake is reported if assessed in the studies. We also explore if global vitamin C status has changed over time. Overall, the review illustrates the shortage of high quality epidemiological studies of vitamin C status in many countries, particularly low- and middle-income countries. The available evidence indicates that vitamin C deficiency is common in low- and middle-income countries and not uncommon in high income settings. Further high quality studies are required to confirm these findings, including in the countries not yet represented, and to fully understand associations with a range of disease processes. Our findings suggest a need for interventions to prevent deficiency in a range of at risk groups and regions of the world.
CONCEPT PAPER | doi:10.20944/preprints202007.0515.v1
Subject: Social Sciences, Economics Keywords: Public Health Intervention, Health Education and Promotion, Behavior Change Intervention, Intervention Design, Multifaceted Intervention, Repeated Intervention, Mental Model Mapping, Low- and Medium-Income Country (LMIC).
Online: 22 July 2020 (10:58:58 CEST)
Improving the effectiveness of health interventions is a major challenge in public health research and program development. A large body of literature has found low or no impact of health education and promotional interventions. We aim to develop a conceptual framework in support of intervention designs for preventive health behavior improvement programs and outcomes. The proposed approach is based on a narrative review of empirical literature assessing the limitations of less effective or ineffective field experiments regarding preventive health education and promotion interventions. We found three major limitations regarding the mental model’s balance of treatment and comparison groups, treatment groups’ willingness to adopt suggested behaviors, and the type, length, frequency, intensity, and sequence of treatments. To minimize the influence of these concerns, we propose a mental model-based repeated multifaceted (MRM) intervention design framework to provide an intervention design for improving health education and promotional programs.