Potential Production Losses Research Articles

A modeling study of cool surfaces and outdoor workers productivity at San Francisco International Airport.

Heat exposure in outdoor work environments poses risks to worker health and productivity. Engineering solutions like cool surfaces that increase surface albedo and reduce temperatures may help mitigate these impacts. We conducted detailed micrometeorological modeling to analyze surface characteristics and heat exposure for outdoor workers at San Francisco International Airport (SFO) under current conditions and three hypothetical albedo-increase scenarios. Wet bulb globe temperature (WBGT) was used to estimate potential productivity loss based on established relationships between heat stress and loss in physical work capacity. For the month of August 2020, we quantified possible gained hours of productivity per worker per month under each hypothetical albedo-increase scenario. Across the entire area of SFO, the average campus albedo was 0.20 (range: 0.08-0.85). Adopting low, moderate, and high albedo modifications for SFO would reduce peak midday WBGT by 0.89, 1.25, and 1.59 °C, respectively. The largest temperature reductions occurred during the morning shift (7 AM-3 PM). In one shift, we found a potential of 5.20, 7.16, and 8.95 h gained per worker over the entire month in the low, moderate, and high albedo modification scenarios, respectively.

A comprehensive review on sand control in oil and gas wells Part I. Mechanical techniques

Sand production is one of the most important problems in the oil and gas industry worldwide and can lead to erosion of surface and downhole equipment, accumulation of sand in wells and facilities, buckling of casing in cased-hole wells, and reduction of well productivity. The erosion of production equipment increases maintenance costs and potential equipment failure. Due to the costs associated with sand control measures and potential production losses, sand production has an impact on project profitability. Environmental concerns can arise if sand-laden produced fluids are discharged untreated, posing a risk to the environment and marine life. To mitigate sand production problems, a variety of sand management and control techniques have been developed and implemented. Over the past several years, sand management and control techniques have advanced considerably due to advances in materials science, well logging, and computational modeling. A better understanding of sand behavior, improved sand control techniques and more accurate predictive models have resulted from these advances. Current developments and strategies in sand management, control and prevention techniques are reviewed in this paper. This review consists of two parts: 1) mechanical techniques and 2) chemical treatment and sand management. Keywords: sand production; gravel packs; pre-packed screens; expandable sand screens; insert screens; patches; chemical consolidation.

Growth and Yield Performance of Chickpea (Cicer arietinum) as Influenced by Irrigation Levels and Genotypes: A Review

Chickpea is mostly cultivated under dryland condition and water availability is the major environmental factor affecting crop yield in dryland conditions. In dryland areas, the crop suffers from moisture stress due to the insecurity of rainfall. The combination of stored soil moisture and high temperatures results in the creation of various degrees of moisture stress during the duration of crop growth, therefore restricting the expression of growth and development characteristics, resulting in a significant loss of crop output. The provision of irrigation proves pivotal for the successful cultivation of chickpea crops during key growth stages, including pre-flowering, pod development and seed filling. Consequently, the implementation of supplemental irrigation serves as a strategic measure to offset potential production losses attributed to terminal drought. This agricultural practice is notably employed in diverse regions worldwide, with a pronounced impact observed in areas such as West Asia and Northern India, where it plays a crucial role in augmenting chickpea productivity. Susceptibility to drought stress has restrained chickpea productivity at a global level, thus, the proper selection of early maturing and drought tolerant cultivars along with supplemental irrigation may be helpful to sustain chickpea production.

Agent-Based Spatial Dynamic Modeling of Diatraea saccharalis and the Natural Parasites Cotesia flavipes and Trichogramma galloi in Sugarcane Crops

In recent years, sugarcane production areas in Brazil have experienced a slower evolution in productivity, and one of the reasons for this is related to the increase in phytosanitary problems, such as the presence of pests. Nevertheless, limited attention has been paid to the development of tools for simulating the spatial dynamics of pests, including their impact on production. This study aims to simulate the potential population growth and dispersal of Diatraea saccharalis (sugarcane borer) in sugarcane crop fields and its estimated impacts on this crop production and to simulate biological control strategies. We developed an agent-based model to simulate the pest population and its dispersal in a one-hectare sugarcane crop field in Pederneiras, São Paulo, Brazil, delimited with the aid of satellite imagery, considering two scenarios: the first without biological control and the second with biological control using the parasites Trichogramma galloi and Cotesia flavipes. The model was developed using the NetLogo 6.3.0 software. The results indicate that the model accurately reproduced the infestation rates reported in the literature. Additionally, it provided insights into expected pest dispersal, potential production losses, and how the use of T. galloi in association with C. flavipes could mitigate production losses. We believe that the model can be used to simulate different biological control strategies and the implementation of integrated pest management (IPM) to achieve adequate control levels and greater productivity in sugarcane production.

Landscape features support natural pest control and farm income when pesticide application is reduced

Future trajectories of agricultural productivity need to incorporate environmental targets, including the reduction of pesticides use. Landscape features supporting natural pest control (LF-NPC) offer a nature-based solution that can serve as a partial substitute for synthetic pesticides, thereby supporting future productivity levels. Here, we introduce a novel approach to quantify the contribution of LF-NPC to agricultural yields and its associated economic value to crop production in a broad-scale context. Using the European Union as case study, we combine granular farm-level data, a spatially explicit map of LF-NPC potential, and a regional agro-economic supply and market model. The results reveal that farms located in areas characterized by higher LF-NPC potential experience lower productivity losses in a context of reduced synthetic pesticides use. Our analysis suggests that LF-NPC reduces yield gaps on average by four percentage points, and increases income by a similar magnitude. These results highlight the significance of LF-NPC for agricultural production and income, and provide a valuable reference point for farmers and policymakers aiming to successfully invest in landscape features to achieve pesticides reduction targets.

Mapping sustainability-oriented China’s cropland use stability

Shifting to more sustainable use can curb cropland resource degradation and improve production resilience. However, most cropland use assessments are unilaterally focused on biophysical levels and productivity, ignoring the multi-dimensional aspects of degraded cropland. This study attempts to describe cropland use stability in China by proposing a multi-dimensional assessment framework (including quantity, quality, management, service, and risk) to provide a reference for designing land degradation-neutral strategies. Results show that multi-dimensional cropland use characteristics present significant spatial heterogeneity. Western regions are reserve resource agglomerations that can replenish cropland quantity. In contrast, main grain-producing areas cover most current resources with preferably cultivation quality, management efficiency, and ecosystem services, while risk resistance is weak (especially in Middle-lower Yangtze Plain). Generally, the stability of cropland use in Northeast Plain is the highest and in Loess Plateau the lowest. Besides, urbanization will occupy about 9.31% of the high-stability cropland in 2030, of which 70.29% will occur in Northeast Plain and Huang-Huai-Hai Plain. The total potential productivity loss in Huang-Huai-Hai Plain alone will reach 100.1 kt, equivalent to supplying the food demand of 199,200 people annually. Therefore, a sustainable-oriented refined cropland management strategy should be designed according to the hierarchical nested spatial layout of comprehensive planning-stability map-multi-dimensional utilization characteristics to ensure the loss-replenishment balance and stable production.

Optimal Preventive Maintenance Scheduling for Wind Turbines under Condition Monitoring

Renewable energy sources, such as wind and solar, are positioned to play a pivotal role in future energy systems. In this paper, we propose a mathematical model for calculating and regularly updating the next preventive maintenance plan for a wind farm. Our optimization criterion considers various factors, including the current ages of key components, major maintenance costs, eventual energy production losses, and available data monitoring the condition of the wind turbines. Employing Cox proportional hazards analysis, we develop a comprehensive approach that accounts for the current ages of critical components, significant maintenance costs, potential energy production losses, and data collected from monitoring the condition of wind turbines. We illustrate the effectiveness of our approach through a case study based on data collected from multiple wind farms in Sweden. Our results demonstrate that preventive maintenance planning yields positive effects, particularly when the wind turbine components in question have significantly shorter lifespans than the turbine itself.

Temperature–humidity index monitoring during two summer seasons in dairy cow sheds in Mugello (Tuscany)

Many studies have reported that the impact of high temperatures affects physiology, welfare, health, and productivity of farm animals, and among these, the dairy cattle farming is one of the livestock sectors that suffers the greatest effects. The temperature–humidity index (THI) represents the state of the art in the evaluation of heat stress conditions in dairy cattle but often its measurement is not carried out in sheds. For this reason, the aim of this study was the monitoring of the THI in three dairy cattle farms in Mugello (Tuscany) to understand its influence on dairy cows. THI values were calculated using meteorological data from direct observation in sheds and outdoor environments. Data relating to the animal’s behavior were collected using radio collars. The Pearson test and Mann–Kendall test were used for statistical analysis. The results highlighted a significant (P < 0.001) upward trend in THImax during the last 30 years both in Low Mugello (+ 1.1 every 10 years) and in High Mugello (+ 0.9 every 10 years). In Low Mugello sheds, during the period 2020–2022, more than 70% of daytime hours during the summer period were characterized by heat risk conditions (THI > 72) for livestock. On average the animals showed a significant (P < 0.001) decrease in time spent to feeding and rumination, both during the day and the night, with a significant (P < 0.001) increase in inactivity. This study fits into the growing demand for knowledge of the micro-climatic conditions within farms in order to support resilience actions for protecting both animal welfare and farm productivity from the effects of climate change. This could also be carried out thanks to estimation models which, based on the meteorological conditions forecast, could implement the thermal stress indicator (THI) directly from the high-resolution meteorological model, allowing to get a prediction of the farm’s potential productivity loss based on the expected THI.

DYNAMICS OF ECOLOGICAL AND AGRO-ECOLOGICAL INDICES (UNDER CONDITIONS OF PHYSICAL AND CHEMICAL DEGRADATION) OF SOILS RESEARCHED ON THE GENETIC HORIZONS

The basic concept of land degradation, as outlined in different definitions, refers to the loss of real or potential productivity and utility of land and the decrease in its quality. Due to various farming methods that decarbonize soil and make it less robust and poor in nutrients, soil is being lost at a rate 10 to 40 times higher than it can be naturally replenished. From the above, many questions arise regarding the sustainability of today's agriculture on the territory of the Republic of Moldova and this is due to several reasons: loss of biodiversity, loss of land quality through the process of soil erosion, pollution from chemical fertilizers and pesticides administered inadequately, non-compliance with the employment contracts, etc. The main purpose consists in the comparative assessment of the indices modified by the agropedogenetic process of the soils evolved under natural and arable conditions, as well as their qualitative state in Tîrnova commune, Dondușeni district. Physical soil disturbance caused by anthropogenic activities, sometimes inappropriate, is a crucial factor in the conservation of soil quality, moisture availability and crop diversity in agroecosystems. However, the development of agroecological technologies and systems that emphasize the conservation-regeneration of biodiversity, soil, water and other resources is an urgent necessity for both urban and rural areas to cope with an increasing range of socioeconomic and environmental challenges.

Deinococcus radiodurans-derived membrane vesicles protect HaCaT cells against H2O2-induced oxidative stress via modulation of MAPK and Nrf2/ARE pathways

BackgroundDeinococcus radiodurans is a robust bacterium that can withstand harsh environments that cause oxidative stress to macromolecules due to its cellular structure and physiological functions. Cells release extracellular vesicles for intercellular communication and the transfer of biological information; their payload reflects the status of the source cells. Yet, the biological role and mechanism of Deinococcus radiodurans-derived extracellular vesicles remain unclear.AimThis study investigated the protective effects of membrane vesicles derived from D. radiodurans (R1-MVs) against H2O2-induced oxidative stress in HaCaT cells.ResultsR1-MVs were identified as 322 nm spherical molecules. Pretreatment with R1-MVs inhibited H2O2-mediated apoptosis in HaCaT cells by suppressing the loss of mitochondrial membrane potential and reactive oxygen species (ROS) production. R1-MVs increased the superoxide dismutase (SOD) and catalase (CAT) activities, restored glutathione (GSH) homeostasis, and reduced malondialdehyde (MDA) production in H2O2-exposed HaCaT cells. Moreover, the protective effect of R1-MVs against H2O2-induced oxidative stress in HaCaT cells was dependent on the downregulation of mitogen-activated protein kinase (MAPK) phosphorylation and the upregulation of the nuclear factor E2-related factor 2 (Nrf2)/antioxidant response element (ARE) pathway. Furthermore, the weaker protective capabilities of R1-MVs derived from ΔDR2577 mutant than that of the wild-type R1-MVs confirmed our inferences and indicated that SlpA protein plays a crucial role in R1-MVs against H2O2-induced oxidative stress.ConclusionTaken together, R1-MVs exert significant protective effects against H2O2-induced oxidative stress in keratinocytes and have the potential to be applied in radiation-induced oxidative stress models.

Monetary Value of Disability-Adjusted Life Years and Potential Productivity Losses Associated With Neglected Tropical Diseases in the East African Community.

In 2019, the East African Community (EAC) lost 12,048,918 disability-adjusted life-years (DALY) across all ages from neglected tropical diseases (NTDs). The specific objectives of the study reported in the paper were to estimate for EAC the monetary value of DALYs sustained by all ages from NTDs, and the potential productivity losses within the working age bracket of 15 years and above. The EAC total monetary value of DALYs lost from all 20 NTDs is the sum of each partner state's monetary value of DALYs lost from all 20 NTDs. The ith partner state's monetary value of DALY from jth disease equals ith state's GDP per capita net of current health expenditure multiplied by DALYs lost from jth disease in 2019. The EAC total productivity losses attributable to DALYs lost from all 20 NTDs is the sum of lost productivity across the seven partner states. The ith partner state's productivity loss associated with jth disease equals ith state's GDP per capita net of current health expenditure multiplied by DALYs lost from jth disease and the ith state's labour force participation rate adjusted for underutilization (unemployment and time-related underemployment) in 2019. The total 12,048,918 DALYs lost in EAC from NTDs had a of International Dollars (Int$) 21,824,211,076 and an average of Int$ 1811 per DALY. The 2,614,464 DALYs lost from NTD among 15-year-olds and above caused an estimated of Int$ 2,588,601,097 (0.392% of the EAC gross domestic product in 2019), and an average of Int$ 990.1 per DALY. The study succeeded in estimating the monetary value of DALYs sustained by all ages from 20 NTDs, and the potential productivity losses within the working age bracket of 15 years and above in the seven EAC partner states. The DALYs lost from NTD among 15-year-olds and above caused a sizeable loss in the economic productivity of EAC.

Research on the Optimal Energy Saving and Emission Reduction Path for Promoting High-Quality Industrial Development in Hubei Province

In December 2019, a novel coronavirus broke out in Wuhan City, Hubei Province, and, as the center of the coronavirus disease 2019 (COVID-19) epidemic, the economy and production throughout Hubei Province suffered huge temporary impacts. Based on the input–output and industrial pollution emissions data of 33 industrial industries in Hubei from 2010 to 2019, this article uses the non-parametric frontier analysis method to calculate the potential production losses and compliance costs caused by environmental regulations in Hubei’s industrial sector by year and industry. Research has found that the environmental technology efficiency of the industrial sector in Hubei is showing a trend of increasing year-on-year, but the overall efficiency level is still not high, and there is great room for improvement. The calculation results with and without environmental regulatory constraints indicate that, generally, production losses and compliance costs may be encountered in the industrial sector in Hubei, and there are significant differences by industry. The potential production losses and compliance costs in pollution-intensive industries are higher than those in clean production industries. On this basis, we propose relevant policy recommendations to improve the technological efficiency of Hubei’s industrial environment, in order to promote the high-quality development of Hubei’s industry in the post-epidemic era.

The economic cost of fatal workplace accidents in Sweden - A methodology for long-term decision analysis.

The few studies attempting to estimate costs of fatal accidents at workplaces suffer from poor or obscure applied methodologies. As the costs are often limited for the exposed company/industry in the short run, economic decisions about investments to improve the safety and security of workplaces are moreover not made at the societal level nor within an appropriate time frame. In a social economic decision, the total potential productivity lost over time due to a fatal accident is considered regardless of who pays what compensation to the families involved. This study introduces a methodology appropriate for making long-term economic decisions at the societal level to prevent accidents in Swedish workplaces. The introduced methodology, which is based on the human capital approach, is used to assess potential productivity losses associated with the accidents. The empirical findings show that, over the period 2008-2019, Swedish society could have gained more than 8.5 billion Swedish crowns by preventing accidents at Swedish workplaces. The objective achieved as the economic cost of fatal workplace accidents assessed from a long-term societal perspective. Effective preventive measures in the workplace make thus an incredible contribution to society in the form of increased national income, sustainable welfare and economic development.

Trade and Climate Mitigation Interactions Create Agro‐Economic Opportunities With Social and Environmental Trade‐Offs in Latin America and the Caribbean

AbstractThe Latin America and the Caribbean (LAC) region plays key roles in both meeting global agricultural demands and maintaining carbon sinks due to its abundant land and water resources. In this study we use the Global Change Analysis Model to evaluate the opportunities and challenges posed by two global‐scale drivers: agricultural market integration (i.e., reduction of trade barriers) and land‐based climate mitigation policy. We evaluate their potential individual and combined impacts on agricultural production and trade revenues across LAC's economies through mid‐century, as well as the resulting impacts on agricultural consumers and integrated land‐water‐climate systems across LAC's diverse sub‐regions. Increased global market integration results in increased agricultural production and trade revenues for many LAC economies, driven by their evolving comparative advantages. Climate mitigation measures on CO2 and non‐CO2 greenhouse gases increase revenues due to increased agricultural prices from land competition and emissions abatement. The combined outcomes from both drivers are complex and sometimes non‐linear, highlighting the importance of understanding the interactions between multiple drivers. Our results show that increased agricultural production and trade opportunities, from either of the two drivers, pose significant trade‐offs that require careful multi‐sectoral planning, such as emissions reduction challenges, potential loss of livestock production when pursuing land‐based climate mitigation strategies, increased consumer expenditures, and changes in land‐use or water withdrawals, resulting in deforestation or water scarcity pressures. There is considerable heterogeneity in economic and environmental outcomes across LAC sub‐regions and agricultural commodities, illustrating the value of considering outcomes at finer scales.

ПРОГНОЗНІ ОЦІНКИ ВРОЖАЙНОСТІ ТА НЕПРЯМИХ ВТРАТ ВИРОБНИЦТВА ОСНОВНИХ СІЛЬСЬКОГОСПОДАРСЬКИХ КУЛЬТУР В УКРАЇНІ У 2023 РОЦІ В УМОВАХ ВОЄННОГО СТАНУ

Summary The purpose of the work is to highlight the results of forecasting the yield and production of the main agricultural crops in 2023 based on the operational data of remote agromonitoring and the assessment of indirect losses of the gross harvest of grain and leguminous crops in Ukraine under martial law. Methods and materials. Predictive estimates of the yield of agricultural crops are calculated on the basis of statistical data on their productivity for the period 2000-2022 and remote agricultural monitoring data (NDVI indices) on the state of crops in Ukraine in the spring of 2023. Standard methods of correlation-regression analysis were used to establish relationships between NDVI indicators and regional average yield values of the main field crops. Potential indirect production losses of the group of grain and leguminous crops in Ukraine in 2023 were calculated based on the dynamics of the reduction of sowing and harvesting areas in the conditions of martial law and, accordingly, from the losses for the country’s agrarian sector due to the lack of potential profit from the sale of grain, estimated at domestic purchase prices. Results. According to estimates based on actual winter sowing volumes and spring sowing rates, the harvested area of grain and leguminous crops in 2023 is expected to be about 10.4 million hectares. The average yield of grain and leguminous crops in Ukraine as a whole is predicted with a probability of 80-85% at the level of 47-49 t/ha, which according to preliminary estimates is close to last year’s value and the average indicators of the pre-war level. At the same time, the gross harvest of grain and leguminous crops is expected at the level of 48.4-50.5 million tons, compared to the average pre-war level of 75 million tons. That is, the losses from military aggression only for the loss of production of this group of crops currently reach about 25-24 million tons or more than UAH 150 billion. Conclusions. Military aggression against Ukraine will have negative consequences for the cultivation of agricultural crops in 2023, mainly due to the shortage of mineral fertilizers, pesticides and other means of production, the general reduction of sown areas and a number of other negative economic consequences, however, the projected production volumes of grain crops are currently sufficient to ensure needs of the Ukrainian population.

The impact of traumatic brain injury on economic productivity in the Caribbean

IntroductionTraumatic brain injury (TBI) is a significant cause of morbidity and mortality in the Caribbean as well as globally. Within the Caribbean, the prevalence of TBI is approximately 706 per 100,000 persons – one of the highest rates per capita in the world. Research questionWe aim to assess the economic productivity lost due to moderate to severe TBI in the Caribbean. Material and methodsThe annual cost of economic productivity lost in the Caribbean from TBI was calculated from four variables: (1) the number of people with moderate to severe TBI of working age (15–64 years), (2) the employment-to-population ratio, (3) the relative reduction in employment for people with TBI, and (4) per capita Gross Domestic Product (GDP). Sensitivity analyses were performed to evaluate whether the uncertainty of the TBI prevalence data result in substantive changes in the productivity losses. ResultsGlobally, there was an estimated 55 million (95% UI 53, 400, 547 to 57, 626, 214) cases of TBI in 2016 of which 322,291 (95% UI 292,210 to 359,914) were in the Caribbean. Using GDP per capita, we calculated the annual cost of potential productivity losses for the Caribbean to be $1.2 billion. Discussion and conclusionTBI has a significant impact on economic productivity in the Caribbean. With upwards of $1.2 billion lost in economic productivity from TBI, there is an urgent need for appropriate prevention and management of this disease by upscaling neurosurgical capacity. Neurosurgical and policy interventions are necessary to ensure the success of these patients in order to maximize economic productivity.

Evaluating Whether Farmland Consolidation Is a Feasible Way to Achieve a Balance of Potential Crop Production in Southeastern Coastal China

The requisition–compensation balance of farmland (RCBF) policy proposes that all farmland requisitioned for development must be compensated with new farmland, of which the continued implementation in economically developed counties in China faces great challenges. The extent to which a balance of potential crop production can be achieved merely through farmland consolidation has important theoretical and practical significance. This study proposes measurement procedures to investigate this degree and takes seven counties in southeastern coastal China as examples on which to conduct an empirical study. The results show the following: (1) there is a significant negative correlation between GDP and the index of the balance of potential crop production of each county, that is, the more developed the county, the lower the potential to achieve the balance; (2) with an increase in elevation, the possibility of increasing potential crop production shows an inverted U-shaped curve, with the maximum values occurring at elevations between 50 and 500 m and more attention should be paid to farmland with an elevation of between 50 m and 500 m when implementing farmland consolidation projects; (3) although it is difficult for economically developed counties to strike a balance of potential crop production merely through farmland consolidation, the potential of which to compensate for the loss of potential crop production from requisition is great, reaching more than 40%, which plays an important role in realizing the requisition–compensation balance of potential crop production; and (4) the potential of farmland consolidation to compensate for the loss of potential crop production and the difference of which between counties should be paid adequate attention when implementing RCBF policy adjustment. Therefore, the proposed approach illustrated in this study clearly reveals the relationship between the loss of potential crop production from requisition and the compensation of potential crop production by farmland consolidation, which has important implications for the adjustment of the RCBF policy in China.

Effects of Herbicidal Weed Control Practices on Yield Performance of T. Aman Rice Varieties in Bangladesh

Using a weed control scheme could assist in reducing potential production losses caused by weeds in paddy fields. Due to certain undesirable adverse effects, there is currently no realistic alternative to chemical weed suppression approaches in rice. The present research aimed to assess how various herbicide-based weed control techniques influenced the weed profile, and crop production of T. aman rice varieties. The study was done employing a randomized complete block design with 3 trials. The investigation comprised three aman rice cultivars and four weeds control techniques such as control, pre-emergence herbicide, early post emergence and post emergence herbicide. On research sites, ten weed types from 5 families were revealed. The grass weed Echinochloa gras-galli had the highest summed dominance ratio (SDR: 42.05%), while the sedges Scirpus mucronatus had the lowest SDR of 0.81%. Post-emergence herbicide application provided the lowest weed biomass and density at all sampling dates and produced the greatest seed yields (4.25 t ha-1), straw yield (5.41 t ha-1) and harvest index (43.87%) because of minimal crop-weed competition. In the case of interaction, BRRI dhan49 coupled with post emergence herbicide attained maximum output (4.80 t ha-1) followed by BRRI dhan49 with early post emergence. Due to ability for reducing weeds population, usage of post emergence herbicide could be considered as an efficient weed control approach in BRRI dhan49.

Potential productivity loss from uncorrected and under-corrected presbyopia in low- and middle-income countries: A life table modeling study.

ObjectiveTo estimate the burden of potential productivity losses due to uncorrected and under-corrected presbyopia in LMICs among the working-age population in both the cross-sectional and longitudinal manner.MethodsWe extracted data for the prevalence of presbyopia from the Global Burden of Diseases (GBD), Injuries, and Risk Factors Study 2019. Data for the gross domestic product (GDP) per capita were extracted from the World Bank database and Central Intelligence Agency's World Factbook. We introduced life table models to construct age cohorts (in 5-year age groups) of the working-age population (aged from 40 to 64 years old) in LMICs, with simulated follow-up until 65 years old in people with and without uncorrected presbyopia. The differences in productivity-adjusted life years (PALYs) lived and productivity between these two cohorts were calculated. The potential productivity loss was estimated based on GDP per capita. The WHO standard 3% annual discount rate was applied to all years of life and PALYs lived.ResultsIn 2019, there were 238.40 million (95% confidence interval [CI]: 150.92–346.78 million) uncorrected and under-corrected presbyopia cases in LMICs, resulting in 54.13 billion (current US dollars) (95% confidence interval [CI]: 34.34–79.02 billion) potential productivity losses. With simulated follow-up until retirement, those with uncorrected and under-corrected presbyopia were predicted to experience an additional loss of 155 million PALYs (an average loss of 0.7 PALYs per case), which was equivalent to a total loss of US$ 315 billion (an average loss of US$ 1453.72 per person).ConclusionsOur findings highlight the considerable productivity losses due to uncorrected and under-corrected presbyopia in LMICs, especially in a longitudinal manner. There is a great need for the development of enabling eye care policies and programs to create access to eye care services, and more healthcare investment in the correction of presbyopia in the working-age population in LMICs. This study could provide evidences for some potential health-related strategies for socio-economic development.

Update of a Simple Model to Calculate the Annual Global Productivity Loss Due to Blindness and Moderate and Severe Vision Impairment

ABSTRACT Purpose To develop a simple but more precise model to calculate potential annual productivity losses due to blindness and moderate and severe vision impairment (MSVI) at the national, regional, and global level. Methods Productivity loss was defined as the loss of minimum wage/Gross National Income per capita (GNI) incurred by people aged 50–64 years with blindness or MSVI, who were not able to work or worked with reduced earnings in 2020. We developed a global list of minimum wage data from on-line sources. All other model data were sourced from international, standardised, and open-access databases. For blindness, the total productivity loss (not working) incurred by 64%–90% of the affected population was summed up with partial productivity loss, defined as 10%–36% of the affected population earning one-third of that of the sighted population. For MSVI, the total productivity loss for 30%–55% of the affected population was summed with the partial productivity loss, defined as 45%–70% of the affected population having 35% reduced earnings. The costs of blindness and MSVI were summed to obtain the cost of combined vision loss. Results The global cost of vision loss based on minimum wage was US$160-US$216.32 billion for 2020. The global cost of vision loss using GNI was US$449.36-US$584.66 billion. Conclusions A parsimonious model that considers minimum wage and GNI potentially lost due to blindness and MSVI can be used for eye care programming planning and advocacy at the national, regional, and global level.