Tissue stretching is a confounding factor for the evaluation of neurodegeneration in the fast-ageing killifish.

The fast-ageing killifish has gained increasing attention as a promising gerontology model to study age-related processes and neurodegeneration. Interestingly, it is the first vertebrate model organism that shows physiological neuron loss at old age in its central nervous system (CNS), including its brain and retina. However, the fact that the killifish brain and retina are ever-growing tissues complicates studying neurodegenerative events in aged fish. Indeed, recent studies showed that the method of tissue sampling, either using sections or whole-organs, has a large effect on the observed cell densities in the fast-expanding CNS. Here, we elaborated on how these two sampling methods affect neuronal counts in the senescent retina and how this tissue grows upon ageing. Analysis of the different retinal layers in cryosections revealed age-dependent reduction in cellular density but evaluation of whole-mount retinas did not detect any neuron loss, as a result of an extremely fast retinal expansion with age. Using BrdU pulse-chase experiments, we showed that the young adult killifish retina mainly grows by cell addition. However, with increasing age, the neurogenic potency of the retina declines while the tissue keeps on growing. Further histological analyses revealed tissue stretching, including cell size increase, as the main driver of retinal growth at old age. Indeed, both cell size and inter-neuronal distance augment with ageing, thereby decreasing neuronal density. All in all, our findings urge the 'ageing science' community to consider cell quantification bias and employ tissue-wide counting methods to reliably quantify neuronal numbers in this unique gerontology model.

The COVID-19 pandemic and maternal mental health in a fragile and conflict-affected setting in Tumaco, Colombia: a cohort study.

BACKGROUND: The effects of the COVID-19 pandemic on mental health have been understudied among vulnerable populations, particularly in fragile and conflict-affected settings. We aimed to analyse how the pandemic is related to early changes in mental health and parenting stress among caregivers, many of whom are internally displaced persons (IDP), in a conflict-affected setting in Colombia. METHODS: For this cohort study, we used longitudinal data from a psychosocial support programme in which 1376 caregivers were randomly assigned across four sequential cohorts. Recruitment of participants took place in March, 2018, for cohort 1; July, 2018, for cohort 2; March, 2019, for cohort 3; and July, 2019, for cohort 4. Participants completed assessments at baseline, 1-month, and 8-month follow-ups. The 8-month assessment occurred before the COVID-19 pandemic for participants in cohorts 1 and 2 (n=573), whereas those in cohorts 3 and 4 (n=803) were assessed during the early stages of the pandemic, 2-5 weeks after the national lockdown began on March 25, 2020. Primary caregiver anxiety and depression were measured with a scale adapted from the Symptoms Checklist-90-Revised and parenting stress was measured with the short form of the Parenting Stress Index. We estimated how mental health changed by comparing prepandemic and postpandemic 8-month outcomes using lagged-dependent variable models. FINDINGS: Results showed that the likelihood of reporting symptoms above the risk threshold increased by 14 percentage points for anxiety (95% CI 10-17), 5 percentage points for depression (0·5-9), and 10 percentage points for parental stress (5-15). The deterioration in mental health was stronger for IDP, participants with lower education or pre-existing mental health conditions, and for those reporting a higher number of stressors, including food insecurity and job loss. INTERPRETATION: Maternal mental health significantly worsened during the early stages of the pandemic. Considering the vulnerability and pre-existing mental health conditions of this population, the estimated effects are substantial. Policies in fragile and conflict-affected settings targeting IDP and other vulnerable people will be important to mitigate further mental health and socioeconomic problems. FUNDING: Saving Brains-Grand Challenges Canada, Fundación Éxito, Fundación FEMSA, United Way Colombia, Universidad de los Andes. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

Diabetes, employment and behavioural risk factors in China: Marginal structural models versus fixed effects models.

We use longitudinal data from the China Health and Nutrition Survey, covering the years 1997-2011, to estimate the effect of a diabetes diagnosis on an economic outcome (employment probabilities) and behavioural risk factors (alcohol consumption, smoking cessation, body mass index (BMI), physical activity and hypertension) for men and women. We apply two complementary statistical techniques-marginal structural models (MSMs) and fixed effects (FE) models-to deal with confounding. Both methods suggest, despite their different underlying assumptions, similar patterns that indicate important differences between men and women. Employment probabilities decline substantially after the diagnosis for women (-12.4 (MSM) and -15.5 (FE) percentage points), but do not change significantly for men. In particular, the MSM estimates indicate an increase in hypertension (13 percentage points) and a decrease in physical activity for women, while men have small and statistically insignificant changes in these outcomes. For BMI, the MSM results indicate statistically significant changes for men (-.76), but not for women, while the FE estimates show similar reductions for men and women (-.80 and -.73 respectively). Men also reduce their alcohol consumption, but do not cease to smoke. For women these risk factors have a prevalence close to zero to begin with, though women seem to still reduce alcohol consumption somewhat. These results suggest important gender differences in the impact of diabetes in China. To narrow these inequities policies supporting women to reduce diabetes related risk factors are likely important.

The impact of diabetes on labour market outcomes in Mexico: A panel data and biomarker analysis.

Recent evidence for Mexico suggests important differences in health status between people with diagnosed and undiagnosed diabetes. However, there is at best scarce evidence on the economic consequences of diabetes, especially in contexts where the condition often remains undiagnosed, as is typically the case in low- and middle income countries. Using Mexican longitudinal and biomarker data we estimated the relationship between diabetes, as well as its time since diagnosis, and employment probabilities, wages and working hours. We further explored how these relationships differ for those with diagnosed and undiagnosed diabetes. For the longitudinal analyses, nationally representative data from 11995 men and 13858 women 15-64 years old were taken from three waves (2002, 2005, 2009) of the Mexican Family Life Survey. We estimated a fixed effects model to account for unmeasured time-invariant confounders of diabetes. We found a reduction in the probability of being employed of 7.7 and 6.3 percentage points for men and women, respectively, but no significant relationship with hours worked or wages. Employment probabilities fell gradually with each year since diagnosis for men but not for women. Using cross-sectional biomarker data, our results indicate that 68% of those exhibiting glycated hemoglobin (HbA1c) levels above the clinical diabetes threshold did not self-report a diagnosis, hence were undiagnosed. Nevertheless, regression analysis revealed that there was no association of diabetes with labour outcomes for undiagnosed women or men. This suggests that results based on self-reported diabetes cannot be extended to the (rather large) part of the population with undiagnosed diabetes, likely because of a selection of people in worse health and with a longer diabetes duration into the diagnosed population. Earlier diagnosis and improved treatment of diabetes therefore may prevent adverse health effects and related economic hardship.

Microeconomic institutions and personnel economics for health care delivery: a formal exploration of what matters to health workers in Rwanda.

BACKGROUND: Most developing countries face important challenges regarding the quality of health care, and there is a growing consensus that health workers play a key role in this process. Our understanding as to what are the key institutional challenges in human resources, and their underlying driving forces, is more limited. A conceptual framework that structures existing insights and provides concrete directions for policymaking is also missing. METHODS: To gain a bottom-up perspective, we gather qualitative data through semi-structured interviews with different levels of health workers and users of health services in rural and urban Rwanda. We conducted discussions with 48 health workers and 25 users of health services in nine different groups in 2005. We maximized within-group heterogeneity by selecting participants using specific criteria that affect health worker performance and career choice. The discussion were analysed electronically, to identify key themes and insights, and are documented with a descriptive quantitative analysis relating to the associations between quotations. The findings from this research are then revisited 10 years later making use of detailed follow-up studies that have been carried out since then. RESULTS: The original discussions identified both key challenges in human resources for health and driving forces of these challenges, as well as possible solutions. Two sets of issues were highlighted: those related to the size and distribution of the workforce and those related to health workers' on-the-job performance. Among the latter, four categories were identified: health workers' poor attitudes towards patients, absenteeism, corruption and embezzlement and lack of medical skills among some categories of health workers. The discussion suggest that four components constitute the deeper causal factors, which are, ranked in order of ease of malleability, incentives, monitoring arrangements, professional and workplace norms and intrinsic motivation. Three institutional innovations are identified that aim at improving performance: performance pay, community health workers and increased attention to training of health workers. Revisiting the findings from this primary research making use of later in-depth studies, the analysis demonstrates their continued relevance and usefulness. We discuss how the different factors affect the quality of care by impacting on health worker performance and labour market choices, making use of insights from economics and development studies on the role of institutions. CONCLUSION: The study results indicate that health care quality to an important degree depends on four institutional factors at the microlevel that strongly impact on health workers' performance and career choice, and which deserve more attention in applied research and policy reform. The analysis also helps to identify ways forwards, which fit well with the Ministry's most recent strategic plan.

Who wants to work in a rural health post? The role of intrinsic motivation, rural background and faith-based institutions in Ethiopia and Rwanda.

OBJECTIVE: To understand the factors influencing health workers' choice to work in rural areas as a basis for designing policies to redress geographic imbalances in health worker distribution. METHODS: A cohort survey of 412 nursing and medical students in Rwanda provided unique contingent valuation data. Using these data, we performed a regression analysis to examine the determinants of future health workers' willingness to work in rural areas as measured by rural reservation wages. These data were also combined with those from an identical survey in Ethiopia to enable a two-country analysis. FINDINGS: Health workers with higher intrinsic motivation - measured as the importance attached to helping the poor - as well as those who had grown up in a rural area and Adventists who had participated in a local bonding scheme were all significantly more willing to work in a rural area. The main result for intrinsic motivation in Rwanda was strikingly similar to the result obtained for Ethiopia and Rwanda combined. CONCLUSION: Intrinsic motivation and rural origin play an important role in health workers' decisions to work in a rural area, in addition to economic incentives, while faith-based institutions can also influence the decision.

For public service or money: understanding geographical imbalances in the health workforce.

Geographical imbalances in the health workforce have been a consistent feature of nearly all health systems, and especially in developing countries. In this paper we investigate the willingness to work in a rural area among final year nursing and medical students in Ethiopia. Analysing data obtained from contingent valuation questions for final year students from three medical schools and eight nursing schools, we find that there is substantial heterogeneity in the willingness to serve in rural areas. Using both ordinary least squares and maximum likelihood regression analysis, we find that household consumption and the student's motivation to help the poor are the main determinants of willingness to work in a rural area. We carry out a simulation on how much it would cost to get a target proportion of health workers to take up a rural post.

The performance of health workers in Ethiopia: results from qualitative research.

Insufficient attention has been paid to understanding what determines the performance of health workers. This paper reports on findings from focus group discussions with both health workers and users of health services in Ethiopia, a country with some of the poorest health outcomes in the world. We describe performance problems identified by both health users and health workers participating in the focus group discussions, including absenteeism and shirking, pilfering drugs and materials, informal health care provision and illicit charging, and corruption. In the second part of the paper we present four structural reasons why these problems arise: (i) the ongoing transition from health sector dominated by the public sector, towards a more mixed model; (ii) the failure of government policies to keep pace with the transition towards a mixed model of service delivery; (iii) weak accountability mechanisms and the erosion of professional norms in the health sector; and (iv) the impact of HIV/AIDS. The discussions underline the need to base policies on a micro-analysis of how health workers make constrained choices, both in their career and in their day to day professional activities.