Josselin Thuilliez

Decelerating gains in life expectancy ( e ₀ ) in high-income countries have raised concerns about the future of human longevity. To enhance our understanding of these developments, we examine subnational ( N = 450) mortality trends in Western Europe in the period 1992-2019. Between 1992 and 2005, gains in life expectancy were both substantial and widespread. Laggard regions experienced the fastest improvements, yielding rapid regional convergence. Between 2005 and 2019, however, gains in these regions decelerated, while remaining remarkably stable in vanguard regions, suggesting that it remains possible to continue extending longevity. The observed slowing of e ₀ gains is strongly associated with mortality at ages 55-74, which increased in this period across large areas of Western Europe, particularly in Germany and France. In this work, we show that monitoring mortality trends at a fine geographical level is crucial for revealing both the potential for, and challenges to, sustainable progress in human longevity.

A cluster‐randomised controlled trial was conducted in 60 communities in southern Mali to evaluate the impact of micronutrient powders (MNP) combined with seasonal malaria chemoprevention (SMC) on anaemia (primary endpoint), Plasmodium infection, stunting and cognitive function in children < 5 years. The 60 communities were randomly allocated to the intervention or control arm, and cross‐sectional biomedical and cognitive surveys were conducted after 1 and 3 years in a random sample of 3 and 5 years olds (1052 and 1081 children, respectively). All children aged 3–59 m in intervention and control communities received two rounds of SMC each year during the peak malaria season, and in intervention communities, all children aged 6–59 m additionally received 4 months of daily MNP after the peak malaria season. Despite a high baseline prevalence of anaemia and good fidelity to intervention, this trial found no evidence of impact on study outcomes. The prevalence of anaemia was similar in both arms for both age groups after 1 and 3 years of intervention—after 3 years, the prevalence of anaemia amongst 3‐year olds was 57.6% in the intervention arm versus 60.1% in the control group (p = 0.352). For 5‐year olds, it was 51.3% and 53.0%, respectively (p = 0.607). No effect was observed on stunting or cognitive function either.

Many recent studies show that Europe has had a lower mortality inequality for most ages than the United States over the last thirty years. However, the evolution of the income gradient in mortality all along the twentieth century remains poorly understood. This article uses a unique dataset that gives the annual lifetables and fiscal income for the 90 administrative regions of mainland France from 1922 to 2020. The income gradients in mortality are computed across regions using a traditional method with calendar ages and, alternatively, with mortality milestones to control for the increase in life expectancy over time. The study reveals a systematic reversal of the gradient that occurred around the 1970s for both sexes and all ages or mortality groups when calculated at an aggregated level. Inequality in mortality amongst the oldest age groups has however returned to a level observed at least ten years earlier because of Covid-19, even after controlling for mortality improvements over the period.

We provide one of the first formalizations of a vaccination campaign in a decision‐theoretic framework. We analyze a model where an ambiguity‐averse individual must decide how much effort to invest into prevention in the context of a rampant disease. We study how ambiguity aversion affects the effort and the estimation of the vaccine efficacy in clinical trials and immunization campaigns. We find that the behaviors of individuals participating in a clinical trial differ from individuals not participating. Individuals who are more optimistic toward vaccination participate more in trials. Their behaviors and efforts are also affected. As a result, because vaccine efficacy depends on unobserved behaviors and efforts, the biological effect of the vaccine becomes difficult to evaluate. During the scale‐up phase of a vaccination campaign, provided that vaccine efficacy is established, we show that vaccine hesitancy may still be rational.

We provide one of the first formalizations of a vaccination campaign in a decisiontheoretic framework. We analyse a model where an ambiguity-averse individual must decide how much effort to invest into prevention in the context of a rampant disease. We study how ambiguity aversion affects the effort and the estimation of the vaccine efficacy in clinical trials and immunization campaigns. We find that the behaviours of individuals participating in a clinical trial differ from individuals not participating. Individuals who are more optimistic toward vaccination participate more in trials. Their behaviours and efforts are also affected. As a result, because vaccine efficacy depends on unobserved behaviours and efforts, the biological effect of the vaccine becomes difficult to evaluate. During the scale-up phase of a vaccination campaign, provided that vaccine efficacy is established, we show that vaccine hesitancy may still be rational.

Community-based health insurance (CBHI) has been implemented in many low- and middle-income countries to increase financial risk protection in populations without access to formal health insurance. While the design of such social programmes is fundamental to ensuring equitable access to care, little is known about the operational and structural factors influencing enrolment in CBHI schemes. In this study, we took advantage of newly established data monitoring requirements in Senegal to explore the association between the operational capacity and structure of CBHI schemes—also termed ‘mutual health organizations’ (MHO) in francophone countries—and their enrolment levels. The dataset comprised 12 waves of quarterly data over 2017–2019 and covered all 676 MHOs registered in the country. Primary analyses were conducted using dynamic panel data regression analysis. We found that higher operational capacity significantly predicted higher performance: enrolment was positively associated with the presence of a salaried manager at the MHO level (12% more total enrolees, 23% more poor members) and with stronger cooperation between MHOs and local health posts (for each additional contract signed, total enrolees and poor members increased by 7% and 5%, respectively). However, higher operational capacity was only modestly associated with higher sustainability proxied by the proportion of enrolees up to date with premium payment. We also found that structural factors were influential, with MHOs located within a health facility enrolling fewer poor members (−16%). Sensitivity analyses showed that these associations were robust. Our findings suggest that policies aimed at professionalizing and reinforcing the operational capacity of MHOs could accelerate the expansion of CBHI coverage, including in the most impoverished populations. However, they also suggest that increasing operational capacity alone may be insufficient to make CBHI schemes sustainable over time.

Significance: From 1990 to 2018, the Black–White American life expectancy gap fell 48.9% and mortality inequality decreased, although progress stalled after 2012 as life expectancy plateaued. Had improvements continued at the 1990 to 2012 rate, the racial gap in life expectancy would have closed by 2036. Despite decreasing mortality inequality, income-based life expectancy gaps remain starker in the United States than in European countries. At the same time, European mortality improved strongly and even those U.S. populations with the longest life spans–White Americans living in the highest-income areas–experience higher mortality at all ages than Europeans in high-income areas in 2018. Hence, mortality rates of both Black and White Americans could fall much further in both high-income and low-income areas.

This study provides comparisons of inequalities in mortality between the United States, Canada and France using the most recent available data. The period between 2010 and 2018 saw increases in mortality and in inequality in mortality for most age and gender groups in the United States. The main exceptions were children under 5 and adults over 65. In contrast, Canada saw a further flattening of mortality gradients in most groups, as well as further declines in overall mortality. The sole exception was Canadian women over 80 years old, who saw small increases in mortality rates. France saw continuing improvements in mortality rates in all groups. Both Canada and France have distributions of mortality that are much more equal than those in the United States, demonstrating the importance of public policy in the achievement of equality in health.