Centre Population et Développement

The gtsummary package provides an elegant and flexible way to create publication-ready summary tables in R. A critical part of the work of statisticians, data scientists, and analysts is summarizing data sets and regression models in R and publishing or sharing polished summary tables. The gtsummary package was created to streamline these everyday analysis tasks by allowing users to easily create reproducible summaries of data sets, regression models, survey data, and survival data with a simple interface and very little code. The package follows a tidy framework, making it easy to integrate with standard data workflows, and offers many table customization features through function arguments, helper functions, and custom themes.

In highly seasonal environments, offspring production by vertebrates is timed to coincide with the annual peak of resource availability. For herbivores, this resource peak is represented by the annual onset and progression of the plant growth season. As plant phenology advances in response to climatic warming, there is potential for development of a mismatch between the peak of resource demands by reproducing herbivores and the peak of resource availability. For migratory herbivores, such as caribou, development of a trophic mismatch is particularly likely because the timing of their seasonal migration to summer ranges, where calves are born, is cued by changes in day length, while onset of the plant-growing season on the same ranges is cued by local temperatures. Using data collected since 1993 on timing of calving by caribou and timing of plant growth in West Greenland, we document the consequences for reproductive success of a developing trophic mismatch between caribou and their forage plants. As mean spring temperatures at our study site have risen by more than 4 degrees C, caribou have not kept pace with advancement of the plant-growing season on their calving range. As a consequence, offspring mortality has risen and offspring production has dropped fourfold.

Population health intervention research (PHIR) seeks to develop and evaluate policies, programmes and other types of interventions that may affect population health and health equity. Such interventions are strongly influenced by context – taken to refer to any feature of the circumstances in which an intervention is conceived, developed, implemented and evaluated. Understanding how interventions relate to context is critical to understanding how they work; why they sometimes fail; whether they can be successfully adapted, scaled up or translated from one context to another; why their impacts vary; and how far effects observed in one context can be generalised to others. Concerns that context has been neglected in research to develop and evaluate population health interventions have been expressed for at least 20 years. Over this period, an increasingly comprehensive body of guidance has been developed to help with the design, conduct, reporting and appraisal of PHIR. References to context have become more frequent in recent years, as interest has grown in complex and upstream interventions, systems thinking and realist approaches to evaluation, but there remains a lack of systematic guidance for producers, users and funders of PHIR on how context should be taken into account. This document draws together recent thinking and practical experience of addressing context within PHIR. It provides a broad, working definition of context and explains why and how context is important to PHIR. It identifies the dimensions of context that are likely to shape how interventions are conceptualised, the impacts that they have and how they can be implemented, translated and scaled up. It suggests how context should be taken into account throughout the PHIR process, from priority setting and intervention development to the design and conduct of evaluations and reporting, synthesis and knowledge exchange. It concludes by summarising the key messages for producers, users and funders of PHIR and suggesting priorities for future research. The document is meant to be used alongside existing guidance for the development, evaluation and reporting of population health interventions. We expect the guidance to evolve over time, as practice changes in the light of the guidance and experience accumulates on useful approaches. The work was funded by the Canadian Institutes of Health Research (www.cihr-irsc.gc.ca) – Institute of Population and Public Health (CIHR-IPPH) and the UK National Institute for Health Research (NIHR).

International audience

This article adopts a comparative perspective to review the recent increase in the sex ratio at birth (SRB) across Asia. It first describes and compares the most recent birth statistics in Asia in order to identify commonalities in the gradual rise of SRBs observed from Armenia to South Korea. This comparison provides the basis for identifying specific transition patterns in the changes in SRBs. Their recent rise is then interpreted in a social and historical framework borrowed from fertility decline and based on three preconditions: access to sex‐selection technology, preference for male births, and pressure from low fertility. On a broader plane, the process of growing imbalances in the sex composition of the population gives rise to a tragedy of the commons. This article indicates the factors that appear most likely to trigger a turnaround in this transitional demographic situation and to facilitate a return to biologically normal sex ratios in the future.

INTRODUCTION: Countries are working hard to improve access to healthcare through Universal Healthcare Coverage. To genuinely address the problems of healthcare access, we need to recognize all the dimensions and complexities of healthcare access. Levesque's Conceptual Framework of Access to Health introduced in 2013 provides an interesting and comprehensive perspective through the five dimensions of access and the five abilities of the population to access healthcare. The objectives of this paper are to identify and analyze all empirical studies that applied Levesque's conceptual framework for access to healthcare and to explore the experiences and challenges of researchers who used this framework in developing tools for assessing access. METHODS: A scoping review was conducted by searching through four databases, for studies citing Levesque et al. 2013 to select all empirical studies focusing on healthcare access that applied the framework. An initial 1838 documents underwent title screening, followed by abstract screening, and finally full text screening by two independent reviewers. Authors of studies identified from the scoping review were also interviewed. RESULTS: There were 31 studies identified on healthcare access using the Levesque framework either a priori, to develop assessment tool/s (11 studies), or a posteriori, to organize and analyze collected data (20 studies). From the tools used, 147 unique questions on healthcare access were collected, 91 of these explored dimensions of access while 56 were about abilities to access. Those that were designed from the patient's perspective were 73%, while 20% were for health providers, and 7% were addressed to both. Interviews from seven out of the 26 authors, showed that while there were some challenges such as instances of categorization difficulty and unequal representation of dimensions and abilities, the overall experience was positive. CONCLUSION: Levesque's framework has been successfully used in research that explored, assessed, and measured access in various healthcare services and settings. The framework allowed researchers to comprehensively assess the complex and dynamic process of access both in the health systems and the population contexts. There is still potential room for improvement of the framework, particularly the incorporation of time-related elements of access.

Abstract The average age at marriage of women has been rising in most developing countries including India. In this paper we report on the use of case studies, surveys and anthropological methods in a rural area of South India to investigate the mechanisms involved in this change. In an area where all marriages are still arranged it was found that there had been a recent shift from bridewealth to dowry and a diminution in the proportion of all marriages occurring between relatives. The rise in the age at marriage of women was explained by a marriage squeeze resulting from changes in the age structure of the population with mortality decline, an increasing concern of parents of daughters to secure sons-in-law with education and urban occupations, and a growing concept of child dependency. There was no evidence of the rise being a conscious effort to control family size. In the immediate future some women will probably remain unmarried, but the squeeze is already being reduced by a reduction in the age gap between spouses and may be modified considerably by the end of the century as the post-1975 fertility decline affects the age structure of those of marriageable age.

OBJECTIVE: To validate the causes of death determined with a single verbal autopsy instrument covering all age groups in the Agincourt subdistrict of rural South Africa. METHODS: Verbal autopsies (VAs) were conducted on all deaths recorded during annual demographic and health surveillance over a 3-year period (1992-95) in a population of about 63 000 people. Trained fieldworkers elicited signs and symptoms of the terminal illness from a close caregiver, using a comprehensive questionnaire written in the local language. Questionnaires were assessed blind by three clinicians who assigned a probable cause of death using a stepwise consensus process. Validation involved comparison of VA diagnoses with hospital reference diagnoses obtained for those who died in a district hospital; and calculation of sensitivity, specificity and positive predictive value (PPV) for children under 5 years, and adults 15 years and older. RESULTS: A total of 127 hospital diagnoses satisfied the criteria for inclusion as reference diagnoses. For communicable diseases, sensitivity of VA diagnoses among children was 69%, specificity 96%, and PPV 90%; among adults the values were 89, 93 and 76%. Lower values were found for non-communicable diseases: 75, 91 and 86% among children; and 64, 50 and 80% among adults. Most misclassification occurred within the category itself. For deaths due to accidents or violence, sensitivity was 100%, specificity 97%, and PPV 80% among children; and 75, 98 and 60% among adults. Since causes of death were largely age-specific, few differences in sensitivity, specificity and PPV were found for adults and children. The frequency distribution of causes of death based on VAs closely approximated that of the hospital records used for validation. CONCLUSION: VA findings need to be validated before they can be applied to district health planning. In Agincourt, a single verbal autopsy instrument provided a reasonable estimate of the frequency of causes of death among adults and children. Findings can be reliably used to inform local health planning and evaluation.

The 1918 influenza epidemic had a marked and fairly long‐lasting effect on the sex differential in mortality in the United States. After 1918 women lost most of their mortality advantage over men and the female/male gap did not regain its pre‐epidemic level until the 1930s. An analysis of causes of deaths shows a link with tuberculosis. We conjecture the existence of a selection effect, whereby many 1918 influenza deaths were among tuberculous persons, so that tuberculosis death rates dropped in later years, disproportionately among males. Age‐ and sex‐specific data by cause of death corroborate this hypothesis.

Sex‐based discrimination has resulted in severe demographic imbalances between males and females, culminating in a large number of “missing women” in several countries around the world. We provide new estimates and projections of the number of missing females and of the roles played by prenatal and postnatal factors in this imbalance. We estimate time series of the number of missing females, the number of excess female deaths, and the number of missing female births for the world and selected countries. Estimates are provided for 1970–2010 and projections are made from 2010 to 2050. We show that the estimates of these different indicators are consistent with one another and account for the dynamics of the population of missing females over time. We conclude that the number of missing females has steadily risen in the past decades, reaching 126 million in 2010, and the number is expected to peak at 150 million in 2035. Excess mortality was the dominant cause of missing females in the past, and this is expected to remain the case in future decades in spite of the recent rise of prenatal sex selection. The annual number of newly missing females reached 3.4 million in 2010 and is expected to remain above 3 million every year until 2050.

Abstract Objective: To study the effects of zinc supplementation on malaria and other causes of morbidity in young children living in an area holoendemic for malaria in west Africa. Design: Randomised, double blind, placebo controlled efficacy trial. Setting: 18 villages in rural northwestern Burkina Faso. Participants: 709 children were enrolled; 685 completed the trial. Intervention: Supplementation with zinc (12.5 mg zinc sulphate) or placebo daily for six days a week for six months. Main outcome measures: The primary outcome was the incidence of symptomatic falciparum malaria. Secondary outcomes were the severity of malaria episodes, prevalence of malaria parasite, mean parasite densities, mean packed cell volume, prevalence of other morbidity, and all cause mortality. Results: The mean number of malaria episodes per child (defined as a temperature ≥37.5°C with ≥5000 parasites/μl) was 1.7, 99.7% due to infection with Plasmodium falciparum . No difference was found between the zinc and placebo groups in the incidence of falciparum malaria (relative risk 0.98, 95% confidence interval 0.86 to 1.11), mean temperature, and mean parasite densities during malaria episodes, nor in malaria parasite rates, mean parasite densities, and mean packed cell volume during cross sectional surveys. Zinc supplementation was significantly associated with a reduced prevalence of diarrhoea (0.87, 0.79 to 0.95). All cause mortality was non-significantly lower in children given zinc compared with those given placebo (5 v 12, P=0.1). Conclusions: Zinc supplementation has no effect on morbidity from falciparum malaria in children in rural west Africa, but it does reduce morbidity associated with diarrhoea. What is already known on this topic Zinc deficiency is common in infants in developing countries Zinc supplementation has been shown to reduce morbidity from infectious disease in such populations, particularly through reductions in morbidity from diarrhoea and respiratory infections Limited evidence exists for zinc supplementation being effective in reducing morbidity from malaria What this study adds Zinc supplementation has no effect on falciparum malaria in children in rural west Africa It is effective in reducing morbidity from diarrhoea and may help to reduce mortality from all causes

Not all countries make their Covid-19 task force membership list public-the available information varies by country. There is currently a predominance of politicians, virologists and epidemiologists in the Covid-19 response at the country level. Experts on non-Covid-19 health, social and societal consequences of Covid-19 response measures are, for the most part, not included in Covid-19 decisionmaking bodies. There is little transparency regarding whom decision-making bodies are consulting as their source of advice and information. From the available data on Covid-19 decisionmaking entities, female representation is particularly paltry. In addition, civil society is hardly involved in national government decision-making nor its response efforts, barring some exceptions. We need to be more inclusive and multidisciplinary:

Although nitrogen (N) availability is a major determinant of ecosystem properties, little is known about the ecological importance of plants’ preference for ammonium versus nitrate (β) for ecosystem functioning and the structure of communities. We modeled this preference for two contrasting ecosystems and showed that β significantly affects ecosystem properties such as biomass, productivity, and N losses. A particular intermediate value of β maximizes the primary productivity and minimizes mineral N losses. In addition, contrasting β values between two plant types allow their coexistence, and the ability of one type to control nitrification modifies the patterns of coexistence with the other. We also show that species replacement dynamics do not lead to the minimization of the total mineral N pool nor the maximization of plant productivity, and consequently do not respect Tilman’s R* rule. Our results strongly suggest in the two contrasted ecosystems that β has important consequences for ecosystem functioning and plant community structure.

In global health, researchers and decision makers, many of whom have medical, epidemiology or biostatistics background, are increasingly interested in evaluating the implementation of health interventions. Implementation science, particularly for the study of public policies, has existed since at least the 1930s. This science makes compelling use of explicit theories and analytic frameworks that ensure research quality and rigour. Our objective is to inform researchers and decision makers who are not familiar with this research branch about these theories and analytic frameworks. We define four models of causation used in implementation science: intervention theory, frameworks, middle-range theory and grand theory. We then explain how scientists apply these models for three main implementation studies: fidelity assessment, process evaluation and complex evaluation. For each study, we provide concrete examples from research in Cuba and Africa to better understand the implementation of health interventions in global health context. Global health researchers and decision makers with a quantitative background will not become implementation scientists after reading this article. However, we believe they will be more aware of the need for rigorous implementation evaluations of global health interventions, alongside impact evaluations, and in collaboration with social scientists.

I examine the potential impact of the anticipated future marriage squeeze on nuptiality patterns in China and India during the twenty-first century. I use population projections from 2005 to 2100 based on three different scenarios for the sex ratio at birth (SRB). To counteract the limitations of cross-sectional methods commonly used to assess the severity of marriage squeezes, I use a two-sex cohort-based procedure to simulate marriage patterns over the twenty-first century based on the female dominance model. I also examine two more-flexible marriage functions to illustrate the potential impact of changes in marriage schedules as a response to the marriage squeeze. Longitudinal indicators of marriage squeeze indicate that the number of prospective grooms in both countries will exceed that of prospective brides by more 50% for three decades in the most favorable scenario. Rates of male bachelorhood will not peak before 2050, and the squeeze conditions will be felt several decades thereafter, even among cohorts unaffected by adverse SRB. If the SRB is allowed to return to normalcy by 2020, the proportion of men unmarried at age 50 is expected to rise to 15% in China by 2055 and to 10% in India by 2065. India suffers from the additional impact of a delayed fertility transition on its age structures.

Over the past decade, women in Western countries have taken to various social media platforms to share their dissatisfactory experiences with hormonal contraception, which may be pills, patches, rings, injectables, implants or hormonal intrauterine devices (IUDs). These online testimonials have been denounced as spreading "hormonophobia", i.e. an excessive fear of hormones based on irrational causes such as an overestimation of health risks associated with their use, that was already aroused by the recurring media controversies over hormonal contraception. In order to move toward a reproductive justice framework, we propose to study the arguments that women and men (as partners of female users) recently put forward against hormonal contraception to see whether they are related to hormonophobia. The aim of this article is to conduct a systematic review of the recent scientific literature in order to construct an evidence-based typology of reasons for rejecting hormonal contraception, in a continuum perspective from complaints to choosing not to use it, cited by women and men in Western countries in a recent time. The published literature was systematically searched using PubMed and the database from the French National Institute for Demographic Studies (Ined). A total of 42 articles were included for full-text analysis. Eight main categories emerged as reasons for rejecting hormonal contraception: problems related to physical side effects; altered mental health; negative impact on sexuality; concerns about future fertility; invocation of nature; concerns about menstruation; fears and anxiety; and the delegitimization of the side effects of hormonal contraceptives. Thus, arguments against hormonal contraception appeared complex and multifactorial. Future research should examine the provider-patient relationship, the gender bias of hormonal contraception and demands for naturalness in order to understand how birth control could better meet the needs and expectations of women and men in Western countries today.

This paper questions the view that performance-based financing (PBF) in the health sector is an effective, efficient and equitable approach to improving the performance of health systems in low-income and middle-income countries (LMICs). PBF was conceived as an open approach adapted to specific country needs, having the potential to foster system-wide reforms. However, as with many strategies and tools, there is a gap between what was planned and what is actually implemented. This paper argues that PBF as it is currently implemented in many contexts does not satisfy the promises. First, since the start of PBF implementation in LMICs, concerns have been raised on the basis of empirical evidence from different settings and disciplines that indicated the risks, cost and perverse effects. However, PBF implementation was rushed despite insufficient evidence of its effectiveness. Second, there is a lack of domestic ownership of PBF. Considering the amounts of time and money it now absorbs, and the lack of evidence of effectiveness and efficiency, PBF can be characterised as a donor fad. Third, by presenting itself as a comprehensive approach that makes it possible to address all aspects of the health system in any context, PBF monopolises attention and focuses policy dialogue on the short-term results of PBF programmes while diverting attention and resources from broader processes of change and necessary reforms. Too little care is given to system-wide and long-term effects, so that PBF can actually damage health services and systems. This paper ends by proposing entry points for alternative approaches.

INTRODUCTION: Achieving HIV epidemic control globally will require new strategies to accelerate reductions in HIV incidence and mortality. Universal test and treat (UTT) was evaluated in four randomized population-based trials (BCPP/Ya Tsie, HPTN 071/PopART, SEARCH, ANRS 12249/TasP) conducted in sub-Saharan Africa (SSA) during expanded antiretroviral treatment (ART) eligibility by World Health Organization guidelines and the UNAIDS 90-90-90 campaign. DISCUSSION: These three-year studies were conducted in Botswana, Zambia, Uganda, Kenya and South Africa in settings with baseline HIV prevalence from 4% to 30%. Key observations across studies were: (1) Universal testing (implemented via a variety of home and community-based testing approaches) achieved >90% coverage in all studies. (2) When coupled with robust linkage to HIV care, rapid ART start and patient-centred care, UTT achieved among the highest reported population levels of viral suppression in SSA. Significant gains in population-level viral suppression were made in regions with both low and high baseline population viral load; however, viral suppression gains were not uniform across all sub-populations and were lower among youth. (3) UTT resulted in marked reductions in community HIV incidence when universal testing and robust linkage were present. However, HIV elimination targets were not reached. In BCPP and HPTN 071, annualized HIV incidence was approximately 20% to 30% lower in the intervention (which included universal testing) compared to control arms (no universal testing). In SEARCH (where both arms had universal testing), incidence declined 32% over three years. (4) UTT reduced HIV associated mortality by 23% in the intervention versus control communities in SEARCH, a study in which mortality was comprehensively measured. CONCLUSIONS: These trials provide strong evidence that UTT inclusive of universal testing increases population-level viral suppression and decreases HIV incidence and mortality faster than the status quo in SSA and should be adapted at a sub-country level as a public health strategy. However, more is needed, including integration of new prevention interventions into UTT, in order to reach UNAIDS HIV elimination targets.

BACKGROUND: The 2015 WHO recommendation of antiretroviral therapy (ART) for all immediately following HIV diagnosis is partially based on the anticipated impact on HIV incidence in the surrounding population. We investigated this approach in a cluster-randomised trial in a high HIV prevalence setting in rural KwaZulu-Natal. We present findings from the first phase of the trial and report on uptake of home-based HIV testing, linkage to care, uptake of ART, and community attitudes about ART. METHODS AND FINDINGS: Between 9 March 2012 and 22 May 2014, five clusters in the intervention arm (immediate ART offered to all HIV-positive adults) and five clusters in the control arm (ART offered according to national guidelines, i.e., CD4 count ≤ 350 cells/μl) contributed to the first phase of the trial. Households were visited every 6 mo. Following informed consent and administration of a study questionnaire, each resident adult (≥16 y) was asked for a finger-prick blood sample, which was used to estimate HIV prevalence, and offered a rapid HIV test using a serial HIV testing algorithm. All HIV-positive adults were referred to the trial clinic in their cluster. Those not linked to care 3 mo after identification were contacted by a linkage-to-care team. Study procedures were not blinded. In all, 12,894 adults were registered as eligible for participation (5,790 in intervention arm; 7,104 in control arm), of whom 9,927 (77.0%) were contacted at least once during household visits. HIV status was ever ascertained for a total of 8,233/9,927 (82.9%), including 2,569 ascertained as HIV-positive (942 tested HIV-positive and 1,627 reported a known HIV-positive status). Of the 1,177 HIV-positive individuals not previously in care and followed for at least 6 mo in the trial, 559 (47.5%) visited their cluster trial clinic within 6 mo. In the intervention arm, 89% (194/218) initiated ART within 3 mo of their first clinic visit. In the control arm, 42.3% (83/196) had a CD4 count ≤ 350 cells/μl at first visit, of whom 92.8% initiated ART within 3 mo. Regarding attitudes about ART, 93% (8,802/9,460) of participants agreed with the statement that they would want to start ART as soon as possible if HIV-positive. Estimated baseline HIV prevalence was 30.5% (2,028/6,656) (95% CI 25.0%, 37.0%). HIV prevalence, uptake of home-based HIV testing, linkage to care within 6 mo, and initiation of ART within 3 mo in those with CD4 count ≤ 350 cells/μl did not differ significantly between the intervention and control clusters. Selection bias related to noncontact could not be entirely excluded. CONCLUSIONS: Home-based HIV testing was well received in this rural population, although men were less easily contactable at home; immediate ART was acceptable, with good viral suppression and retention. However, only about half of HIV-positive people accessed care within 6 mo of being identified, with nearly two-thirds accessing care by 12 mo. The observed delay in linkage to care would limit the individual and public health ART benefits of universal testing and treatment in this population. TRIAL REGISTRATION: ClinicalTrials.gov NCT01509508.

International audience