Health,income, and the preston curve: A long view

Well-being is increasingly viewed as a multidimensional phenomenon, of which income is only one facet. In this paper I focus on another one, health, and look at its synthetic measure, life expectancy at birth, and its relationship with per capita income. International trends of life expectancy and per capita GDP differed during the past 150 years. Life expectancy gains depended on economic growth but also on the advancement in medical knowledge. The pace and breadth of the health transitions drove life expectancy aggregate tendencies and distribution. The new results confirm the relationship between life expectancy and per capita income and its outward shift over time as put forward by Samuel Preston. However, the association between nonlinearly transformed life expectancy and the log of per capita income does not flatten out over time, but becomes convex suggesting more than proportional increases in life expectancy at higher per capita income levels.     

A Reassessment of the Relationship between GDP and Life Satisfaction

The scientific debate on the relation between Gross Domestic Product (GDP) and self reported indices of life satisfaction is still open. In a well-known finding, Easterlin reported no significant relationship between happiness and aggregate income in time-series analysis. However, life satisfaction appears to be strictly monotonically increasing with income when one studies this relation at a point in time across nations. Here, we analyze the relation between per capita GDP and life satisfaction without imposing a functional form and eliminating potentially confounding country-specific factors. We show that this relation clearly increases in country with a per capita GDP below 15,000 USD (2005 in Purchasing Power Parity), then it flattens for richer countries. The probability of reporting the highest level of life satisfaction is more than 12% lower in the poor countries with a per capita GDP below 5,600 USD than in the counties with a per capita GDP of about 15,000 USD. In countries with an income above 17,000 USD the probability of reporting the highest level of life satisfaction changes within a range of 2% maximum. Interestingly enough, life satisfaction seems to peak at around 30,000 USD and then slightly but significantly decline among the richest countries. These results suggest an explanation of the Easterlin paradox: life satisfaction increases with GDP in poor country, but this relation is approximately flat in richer countries. We explain this relation with aspiration levels. We assume that a gap between aspiration and realized income is negatively perceived; and aspirations to higher income increase with income. These facts together have a negative effect on life satisfaction, opposite to the positive direct effect of the income. The net effect is ambiguous. We predict a higher negative effect in individuals with higher sensitivity to losses (measured by their neuroticism score) and provide econometric support of this explanation.     

Assessing the impact of ambient temperature on the risk of hand,foot, and mouth disease in Guangdong,China: New insight from the disease severity and burden

BackgroundThe association between the incidence of hand, foot, and mouth disease (HFMD) and ambient temperature has been well documented. Although the severity of symptoms is an important indicator of disease burden and varies significantly across cases, it usually was ignored in previous studies, potentially leading to biased estimates of the health impact of temperature.MethodsWe estimated the disability-adjusted life year (DALY) by considering the severity of symptoms for each HFMD case reported during 2010–2012 in Guangdong and used distributed lag-nonlinear models to estimate the association between the daily average temperature and daily DALY of HFMD cases at the city-level. We investigated the potential effect modifiers on the pathway between temperature and DALY and pooled city-specific estimates to a provincial association using a meta-regression. The overall impact of temperature was further evaluated by estimates of DALYs that could be attributed to HFMD.ResultsThe overall cumulative effect of daily mean temperature on the DALY of HFMD showed an inverse-U shape, with the maximum effect estimated to be β = 0.0331 (95%CI: 0.0199–0.0463) DALY at 23.8°C. Overall, a total of 6.432 (95%CI: 3.942–8.885) DALYs (attributable fraction = 2.721%, 95%CI: 1.660–3.759%) could be attributed to temperature exposure. All the demographic subgroups had a similar trend as the main analysis, while the magnitude of the peak of the temperature impact tended to be higher among the males, those aged ≥3yrs or from the Pear-River Delta region. Additionally, the impact of temperature on DALY elevated significantly with the increasing population density, per capita GDP, and per capita green space in parks.ConclusionsTemperature exposure was associated with increased burden of HFMD nonlinearly, with certain groups such as boys and those from areas with greater population density being more vulnerable.     

Economic inequality predicts biodiversity loss

Human activity is causing high rates of biodiversity loss. Yet, surprisingly little is known about the extent to which socioeconomic factors exacerbate or ameliorate our impacts on biological diversity. One such factor, economic inequality, has been shown to affect public health, and has been linked to environmental problems in general. We tested how strongly economic inequality is related to biodiversity loss in particular. We found that among countries, and among US states, the number of species that are threatened or declining increases substantially with the Gini ratio of income inequality. At both levels of analysis, the connection between income inequality and biodiversity loss persists after controlling for biophysical conditions, human population size, and per capita GDP or income. Future research should explore potential mechanisms behind this equality-biodiversity relationship. Our results suggest that economic reforms would go hand in hand with, if not serving as a prerequisite for, effective conservation.     

Cost Effectiveness of Implementing Integrated Management of Neonatal and Childhood Illnesses Program in District Faridabad,India

Introduction

Despite the evidence for preventing childhood morbidity and mortality, financial resources are cited as a constraint for Governments to scale up the key health interventions in some countries. We evaluate the cost effectiveness of implementing IMNCI program in India from a health system and societal perspective.

Methods

We parameterized a decision analytic model to assess incremental cost effectiveness of IMNCI program as against routine child health services for infant population at district level in India. Using a 15-years time horizon from 2007 to 2022, we populated the model using data on costs and effects as found from a cluster-randomized trial to assess effectiveness of IMNCI program in Haryana state. Effectiveness was estimated as reduction in infant illness episodes, deaths and disability adjusted life years (DALY). Incremental cost per DALY averted was used to estimate cost effectiveness of IMNCI. Future costs and effects were discounted at a rate of 3%. Probabilistic sensitivity analysis was undertaken to estimate the probability of IMNCI to be cost effective at varying willingness to pay thresholds.

Results

Implementation of IMNCI results in a cumulative reduction of 57384 illness episodes, 2369 deaths and 76158 DALYs among infants at district level from 2007 to 2022. Overall, from a health system perspective, IMNCI program incurs an incremental cost of USD 34.5 (INR 1554) per DALY averted, USD 34.5 (INR 1554) per life year gained, USD 1110 (INR 49963) per infant death averted. There is 90% probability for ICER to be cost effective at INR 2300 willingness to pay, which is 5.5% of India’s GDP per capita. From a societal perspective, IMNCI program incurs an additional cost of USD 24.1 (INR 1082) per DALY averted, USD 773 (INR 34799) per infant death averted and USD 26.3 (INR 1183) per illness averted in during infancy.

Conclusion

IMNCI program in Indian context is very cost effective and should be scaled-up as a major child survival strategy.     

Income Inequality,Economic Growth and Stroke Mortality in Brazil: Longitudinal and Regional Analysis 2002-2009

Background and Purpose

Stroke accounts for more than 10% of all deaths globally and most of it occurs in low- and middle-income countries (LMIC). Income inequality and gross domestic product (GDP) per capita has been associated to stroke mortality in developed countries. In LMIC, GDP per capita is considered to be a more relevant health determinant than income inequality. This study aims to investigate if income inequality is associated to stroke mortality in Brazil at large, but also on regional and state levels, and whether GDP per capita modulates the impact of this association.

Methods

Stroke mortality rates, Gini index and GDP per capita data were pooled for the 2002 to 2009 period from public available databases. Random effects models were fitted, controlling for GDP per capita and other covariates.

Results

Income inequality was independently associated to stroke mortality rates, even after controlling for GDP per capita and other covariates. GDP per capita reduced only partially the impact of income inequality on stroke mortality. A decrease in 10 points in the Gini index was associated with 18% decrease in the stroke mortality rate in Brazil.

Conclusions

Income inequality was independently associated to stroke mortality in Brazil.     

Development of human health damage factors related to CO<Subscript>2</Subscript> emissions by considering future socioeconomic scenarios

Purpose

Global warming is exerting a damaging effect on human health. This damage is not only influenced by future climate conditions but also projected economic development and population growth. That being said, there are no health damage factors related to CO₂ emissions which take into account future socioeconomic scenarios in life cycle impact assessment (LCIA). Thus, the purpose of the current research is to calculate human health damage factors based on the Special Report on Emission Scenarios (SRESs) developed by the Intergovernmental Panel on Climate Change (IPCC).

Methods

The procedure used to calculate the SRES-based damage factors is as follows. First, a framework was developed to calculate damage factors based on multiple parameters: rise in temperature, relative risk increase, mortality rate increase, rise in number of deaths, and disability-adjusted life year (DALY) increase. Secondly, these parameters were calculated for each individual SRES based on the relationship among the parameters and CO₂ emissions, GDP, and population values of each scenario. Finally, the damage factor for each SRES was calculated by multiplying all the parameters that had been calculated based on the CO₂ emission, GDP, and population data in the corresponding scenarios.

Results and discussion

Using this method, the human health damage factors for four SRESs (A1B, A2, B1, and B2) were calculated. The damage factors consisted of six different items: malaria, diarrhea, cardiovascular disease, malnutrition, coastal flooding, and inland flooding. The calculated results by scenario were 2.0?×?10^?7, 6.2?×?10^?7, 2.1?×?10^?7, and 4.2?×?10^?7 DALY/kg CO₂, respectively. The damage caused by malnutrition is the greatest, followed by diarrhea. Regions of Southeast Asia, Africa, and the Middle East showed the highest damages due to their high damage from malnutrition and diarrhea. With regard to the differences among the four damage factors, the difference between the projected future mortality rate and DALY per death based on the future GDP per capita is greater than the difference between the increases in temperature among scenarios dependent on future CO₂ emission.

Conclusions

The human health damage factors related to CO₂ emissions for four SRESs were estimated. As a result of differences between future socioeconomic scenarios, the largest amount of damage per CO₂ emission unit was three times greater than the smallest amount. Therefore, sensitive analysis is highly recommended when seeking to compare damage caused by global warming and other impact categories.

     

Life cycle sustainability assessment of autonomous heavy‐duty trucks

Connected and automated vehicles (CAVs) are emerging technologies expected to bring important environmental, social, and economic improvements in transportation systems. Given their implications in terms of air quality and sustainable and safer movement of goods, heavy‐duty trucks (HDTs), carrying the majority of U.S. freight, are considered an ideal domain for the application of CAV technology. An input–output (IO) model is developed based on the Eora database—a detailed IO database that consists of national IO tables, covering almost the entire global economy. Using the Eora‐based IO model, this study quantifies and assesses the environmental, economic, and social impacts of automated diesel and battery electric HDTs based on 20 macro‐level indicators. The life cycle sustainability performances of these HDTs are then compared to that of a conventional diesel HDT. The study finds an automated diesel HDT to cause 18% more fatalities than an automated electric HDT. The global warming potential (GWP) of automated diesel HDTs is estimated to be 4.7 thousand metric tons CO₂‐eq. higher than that of automated electric HDTs. The health impact costs resulting from an automated diesel HDT are two times higher than that of an automated electric HDT. Overall, the results also show that automation brings important improvements to the selected sustainability indicators of HDTs such as global warming potential, life cycle cost, GDP, decrease in import, and increase in income. The findings also show that there are significant trade‐offs particularly between mineral and fossil resource losses and environmental gains, which are likely to complicate decision‐making processes regarding the further development and commercialization of the technology.     

Estimating the household costs of human–wildlife conflict in China’s giant panda national park

Human–wildlife conflict is a major cause of losses resulting from the establishment of protected areas, most of which are borne by the communities within these areas. It is therefore important to establish a compensation system for such losses. This study measures the total costs of human-wildlife conflict by surveying communities within and surrounding China's Giant Panda National Park. The results show that the primary visible costs from human–wildlife conflict, which include crop loss, livestock depredation, property damage, and human fatalities and injury, were 2185.6 Yuan ($316.9) per household. Approximately 64.9% of households were affected by this conflict in 2020. For each affected household, the average visible costs per capita was 952.6 Yuan ($138.1) or 7.2% of per capita net income. When converting well-being losses caused by human-wildlife conflict into economic costs, we consider visible costs and hidden costs (e.g., transaction, opportunity, and health costs). This study shows that human–wildlife conflict reduced per capita net income by 15.3% and significantly affected household well-being. The average cost of the well-being loss caused by human-wildlife conflict was 38.5 % of per capita net income.     

Peak Waste: When Is It Likely to Occur?

Population and per capita gross domestic product (GDP) projections are used to estimate total global municipal solid waste (MSW) generation over the twenty‐first century. Some projections for global population suggest that it will peak this century. Waste generation rates per capita generally increase with affluence, although in the most affluent countries there is also a trend toward dematerialization. The confluence of these factors means that at some point in the future total global waste generation could possibly peak. To determine when peak waste might occur, we used the shared‐socioeconomic pathway scenarios (used in Intergovernmental Panel on Climate Change [IPCC] studies) combined with estimates of municipal solid waste (MSW) generation rates, extrapolated from our work for the World Bank. Despite the expectation that total MSW generation in Organisation for Economic Co‐operation and Development (OECD) and high‐income countries will peak mid‐century, with current trajectories global peak waste is not expected before 2100. The peak could be moved forward to around 2075 and reduced in intensity by some 30% if a more aggressive sustainability growth scenario were followed, rather than the current business‐as‐usual scenario. Further, the magnitude of peak waste is sensitive to the intensity of waste generation; it could vary from 7.3 to 10.9 megatonnes per day under the sustainability scenario. The timing of peak waste will substantially depend on the development of cities in Sub‐Saharan Africa, where population growth rates are more than double the rest of the world.     

Antenatal Syphilis Screening Using Point-Of-Care Testing in Low- and Middle-Income Countries in Asia and Latin America: A Cost-Effectiveness Analysis

BackgroundUntreated syphilis in pregnancy is associated with adverse clinical outcomes to the infant. In low- and middle-income countries in Asia and Latin America, 20%-30% of women are not tested for syphilis during pregnancy. We evaluated the cost-effectiveness of increasing the coverage for antenatal syphilis screening in 11 Asian and 20 Latin American countries, using a point-of-care immunochromatographic strip (ICS) test.MethodsThe decision analytical cost-effectiveness models reported incremental costs per disability-adjusted life years (DALYs) averted from the perspectives of the national health care payer. Clinical outcomes were stillbirths, neonatal deaths, and congenital syphilis. DALYs were computed using WHO disability weights. Costs included the ICS test, three injections of benzathine penicillin, and nurse wages. Country-specific inputs included the antenatal prevalence of syphilis and the proportion of women in the antenatal care setting that are screened for syphilis infection as reported in the 2014 WHO baseline report on global sexually transmitted infection surveillance. Country-specific data on the annual number of live births, proportion of women with at least one antenatal care visit, and per capita gross national income were also included in the model.ResultsThe incremental cost/DALY averted of syphilis screening is US$53 (range: US$10-US$332; Prob<1*per capita GDP=99.71%) in Asia and US$60 (range: US$5-US$225; Prob<1*per capita GDP=99.77%) in Latin America. Universal screening may reduce the annual number of stillbirths by 20,344 and 4,270, neonatal deaths by 8,201 and 1,721, cases of congenital syphilis by 10,952 and 2,298, and avert 925,039 and 197,454 DALYs in the aggregate Asian and Latin American panel, respectively.ConclusionAntenatal syphilis screening is highly cost-effective in all the 11 Asian and 20 Latin American countries assessed. Our findings support the decision to expand syphilis screening in countries with currently low screening rates or continue national syphilis screening programs in countries with high rates.     

Inferring the economic standard of living and health from cohort height: Evidence from modern populations in developing countries

Average adult height is a physical measure of the biological standard of living of a population. While the biological and economic standards of living of a population are very different concepts, they are linked and may empirically move together. If this is so, then cohort heights can also be used to make inferences about the economic standard of living and health of a population when other data are not available. We investigate how informative this approach is in terms of inferring income, nutrition, and mortality using data on heights from developing countries over the last 50 years for female cohorts born 1951–1992. We find no evidence that the absolute differences in adult height across countries are associated with different economic living standards. Within countries, however, faster increases in adult cohort height over time are associated with more rapid growth of GDP per capita, life expectancy, and nutritional intake. Using our instrumental variable approach, each centimeter gain in height is associated with a 6% increase in income per capita, a reduction in infant mortality of 7 per thousand (or an 1.25 year increase in life expectancy), and an increase in nutrition of 64 calories and 2 grams of protein per person per day relative to the global trend. We find that increases in cohort height can predict increases in income even for countries not used in the estimation of the relationship. This suggests our approach has predictive power out of sample for countries where we lack income and health data.     

Impact of the Economic Structure of Cities on Urban Scaling Factors: Implications for Urban Material and Energy Flows in China

We explore the population‐scaling and gross domestic product (GDP)‐scaling relationships of material and energy flow (MEF) parameters in different city types based on economic structure. Using migration‐corrected population data, we classify 233 Chinese city propers (Shiqu) as “highly industrial” (share of secondary GDP exceeds 63.9%), “highly commercial” (share of tertiary GDP exceeds 52.6%), and “mixed‐economy” (the remaining cities). We find that, first, the GDP population‐scaling factors differ in the different city types. Highly commercial and mixed‐economy cities exhibit superlinear GDP population‐scaling factors greater than 1, whereas highly industrial cities are sublinear. Second, GDP scaling better correlates with city‐wide MEF parameters in Chinese cities; these scaling relationships also show differences by city typology. Third, highly commercial cities are significantly different from others in demonstrating greater average per capita household income creation relative to per capita GDP. Further, highly industrial cities show an apparent cap in population. This also translates to lower densities in highly industrial cities compared to other types, showing a size effect on urban population density. Finally, a multiple variable regression of total household electricity showed significant and positive correlation with population, income effect, and urban form effect. With such multivariate modeling, the apparent superlinearity of household electricity use with respect to population is no longer observed. Our study enhances understanding of MEFs associated with Chinese cities and provides new insights into the patterns of scaling observed in different city types by economic structure. Results recommend dual scaling by GDP and by population for MEF parameters and suggest caution in applying universal scaling factors to all cities in a country.     

A Systematic Review of Studies Eliciting Willingness-to-Pay per Quality-Adjusted Life Year: Does It Justify CE Threshold?

Background

A number of studies have been conducted to estimate willingness to pay (WTP) per quality-adjusted life years (QALY) in patients or general population for various diseases. However, there has not been any systematic review summarizing the relationship between WTP per QALY and cost-effectiveness (CE) threshold based on World Health Organization (WHO) recommendation.

Objective

To systematically review willingness-to-pay per quality-adjusted-life-year (WTP per QALY) literature, to compare WTP per QALY with Cost-effectiveness (CE) threshold recommended by WHO, and to determine potential influencing factors.

Methods

We searched MEDLINE, EMBASE, Psyinfo, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Center of Research Dissemination (CRD), and EconLit from inception through 15 July 2014. To be included, studies have to estimate WTP per QALY in health-related issues using stated preference method. Two investigators independently reviewed each abstract, completed full-text reviews, and extracted information for included studies. We compared WTP per QALY to GDP per capita, analyzed, and summarized potential influencing factors.

Results

Out of 3,914 articles founded, 14 studies were included. Most studies (92.85%) used contingent valuation method, while only one study used discrete choice experiments. Sample size varied from 104 to 21,896 persons. The ratio between WTP per QALY and GDP per capita varied widely from 0.05 to 5.40, depending on scenario outcomes (e.g., whether it extended/saved life or improved quality of life), severity of hypothetical scenarios, duration of scenario, and source of funding. The average ratio of WTP per QALY and GDP per capita for extending life or saving life (2.03) was significantly higher than the average for improving quality of life (0.59) with the mean difference of 1.43 (95% CI, 1.81 to 1.06).

Conclusion

This systematic review provides an overview summary of all studies estimating WTP per QALY studies. The variation of ratio of WTP per QALY and GDP per capita depended on several factors may prompt discussions on the CE threshold policy. Our research work provides a foundation for defining future direction of decision criteria for an evidence-informed decision making system.     

Will income inequality affect environmental quality? Analysis based on China's provincial panel data

During the last two decades of China's rapid economic growth, the gap in citizens’ income has widened and environmental quality has deteriorated. Using Gini coefficients as the measure of income inequality, this study investigated the impacts of income inequality on carbon emissions per capita in China. To control for potential endogeneity and allow for dynamics, the Generalized Method of Moments (GMM) technique is utilized. Moreover, the influential factors that can affect carbon emissions per capita in China have been examined. The empirical results indicate that carbon emissions per capita increase as the income gap expands for nationwide and in the eastern and non-eastern regions of China. Among all factors that may affect carbon emissions per capita, a “U” shaped relationship exists between per capita income and per capita carbon emissions, and increasing the value-added share of secondary industry in the GDP would significantly increase carbon emissions per capita.     

Socioeconomic interactions with physique and fertility

The reproductive histories of 4829 white women who participated in the Ten State Nutrition Survey of 1968-1970 were analyzed in the attempt to study socioeconomic interactions with physique and fertility. Socioeconomic data included per-capita income. The range of per capita incomes in the sample was from $12 per capita for those on public assistance to $30,000 per capita, and distinctly skewed to the lower incomes. Most incomes were clustered between $500 and $5000. Associations between 5 measures of physique and fertility were explained by socioeconomic influences -- the per capita income. The exact relation between social variables and physique, as part of this triangle, did not yield gracefully to delineation. The rich were systematically leanest and for females, at least decreasing socioeconomic status appeared to be associated with increasing fatness. Stature was less predictable, appearing to ascend with social class or income. There was a systematic decrease in number of liveborn children, for mothers of completed reproduction, with increasing income. The lowest 3 income levels were each significantly different from each other and contrasted with all other levels. This socially-determined differential fertility of physique categories appeared to be linear rather than modal in character; income and fertility interacted in a curvilinear manner. The data also suggest the existence of a secular trend for certain physical characteristics, particularly fatness, which are subject to social transmission between generations.     

Assessment of the Association of Health with the Liberalisation of Trade in Services under the World Trade Organisation

Background

The liberalisation of trade in services which began in 1995 under the General Agreement on Trade in Services (GATS) of the World Trade Organisation (WTO) has generated arguments for and against its potential health effects. Our goal was to explore the relationship between the liberalisation of services under the GATS and three health indicators - life expectancy (LE), under-5 mortality (U5M) and maternal mortality (MM) - since the WTO was established.

Methods and Findings

This was a cross-sectional ecological study that explored the association in 2010 and 1995 between liberalisation and health (LE, U5M and MM), and between liberalisation and progress in health in the period 1995–2010, considering variables related to economic and social policies such as per capita income (GDP pc), public expenditure on health (PEH), and income inequality (Gini index). The units of observation and analysis were WTO member countries with data available for 2010 (n = 116), 1995 (n = 114) and 1995–2010 (n = 114). We conducted bivariate and multivariate linear regression analyses adjusted for GDP pc, Gini and PEH. Increased global liberalisation in services under the WTO was associated with better health in 2010 (U5M: −0.358 p<0.001; MM: −0.338 p = 0.001; LE: 0.247 p = 0.008) and in 1995, after adjusting for economic and social policy variables. For the period 1995–2010, progress in health was associated with income equality, PEH and per capita income. No association was found with global liberalisation in services.

Conclusions

The favourable association in 2010 between health and liberalisation in services under the WTO seems to reflect a pre-WTO association observed in the 1995 data. However, this liberalisation did not appear as a factor associated with progress in health during 1995–2010. Income equality, health expenditure and per capita income were more powerful determinants of the health of populations.     

Impact of Individual and Environmental Socioeconomic Status on Peritoneal Dialysis Outcomes: A Retrospective Multicenter Cohort Study

Objectives

We aimed to explore the impacts of individual and environmental socioeconomic status (SES) on the outcome of peritoneal dialysis (PD) in regions with significant SES disparity, through a retrospective multicenter cohort in China.

Methods

Overall, 2,171 incident patients from seven PD centers were included. Individual SES was evaluated from yearly household income per person and education level. Environmental SES was represented by regional gross domestic product (GDP) per capita and medical resources. Undeveloped regions were defined as those with regional GDP lower than the median. All-cause and cardiovascular death and initial peritonitis were recorded as outcome events.

Results

Poorer PD patients or those who lived in undeveloped areas were younger and less-educated and bore a heavier burden of medical expenses. They had lower hemoglobin and serum albumin at baseline. Low income independently predicted the highest risks for all-cause or cardiovascular death and initial peritonitis compared with medium and high income. The interaction effect between individual education and regional GDP was determined. In undeveloped regions, patients with an elementary school education or lower were at significantly higher risk for all-cause death but not cardiovascular death or initial peritonitis compared with those who attended high school or had a higher diploma. Regional GDP was not associated with any outcome events.

Conclusion

Low personal income independently influenced all-cause and cardiovascular death, and initial peritonitis in PD patients. Education level predicted all-cause death only for patients in undeveloped regions. For PD patients in these high risk situations, integrated care before dialysis and well-constructed PD training programs might be helpful.     

The potential economic value of a Trypanosoma cruzi (Chagas disease) vaccine in Latin America

Background

Chagas disease, caused by the parasite Trypanosoma cruzi (T. cruzi), is the leading etiology of non-ischemic heart disease worldwide, with Latin America bearing the majority of the burden. This substantial burden and the limitations of current interventions have motivated efforts to develop a vaccine against T. cruzi.

Methodology/Principal Findings

We constructed a decision analytic Markov computer simulation model to assess the potential economic value of a T. cruzi vaccine in Latin America from the societal perspective. Each simulation run calculated the incremental cost-effectiveness ratio (ICER), or the cost per disability-adjusted life year (DALY) avoided, of vaccination. Sensitivity analyses evaluated the impact of varying key model parameters such as vaccine cost (range: $0.50–$200), vaccine efficacy (range: 25%–75%), the cost of acute-phase drug treatment (range: $10–$150 to account for variations in acute-phase treatment regimens), and risk of infection (range: 1%–20%). Additional analyses determined the incremental cost of vaccinating an individual and the cost per averted congestive heart failure case. Vaccination was considered highly cost-effective when the ICER was ≤1 times the GDP/capita, still cost-effective when the ICER was between 1 and 3 times the GDP/capita, and not cost-effective when the ICER was >3 times the GDP/capita. Our results showed vaccination to be very cost-effective and often economically dominant (i.e., saving costs as well providing health benefits) for a wide range of scenarios, e.g., even when risk of infection was as low as 1% and vaccine efficacy was as low as 25%. Vaccinating an individual could likely provide net cost savings that rise substantially as risk of infection or vaccine efficacy increase.

Conclusions/Significance

Results indicate that a T. cruzi vaccine could provide substantial economic benefit, depending on the cost of the vaccine, and support continued efforts to develop a human vaccine.     

Trends and scenarios of the carbon budget in postagricultural Puerto Rico (1936–2060)

Contrary to the general trend in the tropics, Puerto Rico underwent a process of agriculture abandonment during the second half of the 20th century as a consequence of socioeconomic changes toward urbanization and industrialization. Using data on land‐use change, biomass accumulation in secondary forests, and ratios between gross domestic product (GDP) and carbon emissions, we developed a model of the carbon budget for Puerto Rico between 1936 and 2060. As a consequence of land abandonment, forests have expanded rapidly since 1950, achieving the highest sequestration rates between 1980 and 1990. Regardless of future scenarios of demography and land use, sequestration rates will decrease in the future because biomass accumulation decreases with forest age and there is little agricultural land remaining to be abandoned. Due to high per‐capita consumption and population density, carbon emissions of Puerto Rico have increased dramatically and exceeded carbon sequestration during the second half of the 20th century. Although Puerto Rico had the highest percent of reforestation for a tropical country, emissions during the period 1950–2000 were approximately 3.5 times higher than sequestration, and current annual emission is almost nine times the rate of sequestration. Additionally, while sequestration will decrease over the next six decades, current socioeconomic trends suggest increasing emissions unless there are significant changes in energy technology or consumption patterns. In conclusion, socioeconomic changes leading to urbanization and industrialization in tropical countries may promote high rates of carbon sequestration during the decades following land abandonment. Initial high rates of carbon sequestration can balance emissions of developing countries with low emission/GDP ratio. In Puerto Rico, the socioeconomic changes that promoted reforestation also promoted high‐energy consumption, and resulted in a net increase in carbon emissions.