Improving Usefulness of Cognitive Decline Population Measures in Predicting Future Dementia Burden

Alzheimer’s disease and related dementias begin with mild early symptoms of memory loss, progressing to more severe cognitive and functional impairment. Reports of worsening memory and subjective cognitive decline (SCD) are often the earliest possible signs of dementia onset. The trajectory of certain types of dementia may require early detection of worsening memory in the disease progression for successful interventions. However, the predictive value of subjective measures of cognitive decline is limited; the majority of those who report subjective symptoms do not progress to diagnosed cognitive impairment or dementia. These two realities create a significant challenge in confronting the growing dementia crisis. Population-level data can be beneficial in tracking trends in SCD. Data from the Behavioral Risk Factor Surveillance System (BRFSS) core questions related to chronic diseases and from the SCD optional module from survey years 2015-2019 were aggregated across the participating 50 states, D.C., and Puerto Rico for this analysis. Among 181,097 U.S. respondents aged ≥45 years, 11.3% (95% CI=10.9-11.6) reported SCD; among 20,424 with SCD symptoms, 39.4% (37.6-40.6) reported functional difficulties associated with SCD symptoms and 33.9% (32.4-35.5) needed assistance with day-to-day activities resulting from symptoms. Studies suggest persons experiencing SCD symptoms and associated functional difficulties are at increased risk for dementia compared with those with SCD without functional difficulties. Combining responses about SCD with associated functional difficulties, anxiety, and other measures might help to better inform the future burden of more severe cognitive impairment than SCD status alone.

Modeling COVID-19 care capacity in a major health system

Hospital resources, especially critical care beds and ventilators, have been strained by additional demand throughout the COVID-19 pandemic. Rationing of scarce critical care resources may occur when available resource limits are exceeded. However, the dynamic nature of the COVID-19 pandemic and variability in projections of the future burden of COVID-19 infection pose challenges for optimizing resource allocation to critical care units in hospitals. Connecticut experienced a spike in the number of COVID-19 cases between March and June 2020. Uncertainty about future incidence made it difficult to predict the magnitude and duration of the increased COVID-19 burden on the healthcare system. In this paper, we describe a model of COVID-19 hospital capacity and occupancy that generates estimates of the resources necessary to accommodate COVID-19 patients under infection scenarios of varying severity. We present the model structure and dynamics, procedure for parameter estimation, and publicly available web application where we implemented the tool. We then describe calibration using data from over 3,000 COVID-19 patients seen at the Yale-New Haven Health System between March and July 2020. We conclude with recommendations for modeling tools to inform decision-making using incomplete information during future crises.

Quantifying previous SARS-CoV-2 infection through mixture modelling of antibody levels

As countries decide on vaccination strategies and how to ease movement restrictions, estimating the proportion of the population previously infected with SARS-CoV-2 is important for predicting the future burden of COVID-19. This proportion is usually estimated from serosurvey data in two steps: first the proportion above a threshold antibody level is calculated, then the crude estimate is adjusted using external estimates of sensitivity and specificity. A drawback of this approach is that the PCR-confirmed cases used to estimate the sensitivity of the threshold may not be representative of cases in the wider population—e.g., they may be more recently infected and more severely symptomatic. Mixture modelling offers an alternative approach that does not require external data from PCR-confirmed cases. Here we illustrate the bias in the standard threshold-based approach by comparing both approaches using data from several Kenyan serosurveys. We show that the mixture model analysis produces estimates of previous infection that are often substantially higher than the standard threshold analysis.

The future of human malnutrition: rebalancing agency for better nutritional health

The major threat to human societies posed by undernutrition has been recognised for millennia. Despite substantial economic development and scientific innovation, however, progress in addressing this global challenge has been inadequate. Paradoxically, the last half-century also saw the rapid emergence of obesity, first in high-income countries but now also in low- and middle-income countries. Traditionally, these problems were approached separately, but there is increasing recognition that they have common drivers and need integrated responses. The new nutrition reality comprises a global ‘double burden’ of malnutrition, where the challenges of food insecurity, nutritional deficiencies and undernutrition coexist and interact with obesity, sedentary behaviour, unhealthy diets and environments that foster unhealthy behaviour. Beyond immediate efforts to prevent and treat malnutrition, what must change in order to reduce the future burden? Here, we present a conceptual framework that focuses on the deeper structural drivers of malnutrition embedded in society, and their interaction with biological mechanisms of appetite regulation and physiological homeostasis. Building on a review of malnutrition in past societies, our framework brings to the fore the power dynamics that characterise contemporary human food systems at many levels. We focus on the concept of agency, the ability of individuals or organisations to pursue their goals. In globalized food systems, the agency of individuals is directly confronted by the agency of several other types of actor, including corporations, governments and supranational institutions. The intakes of energy and nutrients by individuals are powerfully shaped by this ‘competition of agency’, and we therefore argue that the greatest opportunities to reduce malnutrition lie in rebalancing agency across the competing actors. The effect of the COVID-19 pandemic on food systems and individuals illustrates our conceptual framework. Efforts to improve agency must both drive and respond to complementary efforts to promote and maintain equitable societies and planetary health.

Projection of the health and economic impacts of Chronic kidney disease in the Chilean population

Background Chronic Kidney Disease (CKD) is a leading public health problem, with substantial burden and economic implications for healthcare systems, mainly due to renal replacement treatment (RRT) for end-stage kidney disease (ESKD). The aim of this study is to develop a multistate predictive model to estimate the future burden of CKD in Chile, given the high and rising RRT rates, population ageing, and prevalence of comorbidities contributing to CKD. Methods A dynamic stock and flow model was developed to simulate CKD progression in the Chilean population aged 40 years and older, up to the year 2041, adopting the perspective of the Chilean public healthcare system. The model included six states replicating progression of CKD, which was assumed in 1-year cycles and was categorised as slow, medium or fast progression, based on the underlying conditions. We simulated two different treatment scenarios. Only direct costs of treatment were included, and a 3% per year discount rate was applied after the first year. We calibrated the model based on international evidence; the exploration of uncertainty (95% credibility intervals) was undertaken with probabilistic sensitivity analysis. Results By the year 2041, there is an expected increase in cases of CKD stages 3a to ESKD, ceteris paribus, from 442,265 (95% UI 441,808–442,722) in 2021 to 735,513 (734,455–736,570) individuals. Direct costs of CKD stages 3a to ESKD would rise from 322.4M GBP (321.7–323.1) in 2021 to 1,038.6M GBP (1,035.5–1,041.8) in 2041. A reduction in the progression rates of the disease by the inclusion of SGLT2 inhibitors and pre-dialysis treatment would decrease the number of individuals worsening to stages 5 and ESKD, thus reducing the total costs of CKD by 214.6M GBP in 2041 to 824.0M GBP (822.7–825.3). Conclusions This model can be a useful tool for healthcare planning, with development of preventive or treatment plans to reduce and delay the progression of the disease and thus the anticipated increase in the healthcare costs of CKD.

704The preventable future burden of cancer in Australia

Background Estimates of the future burden of invasive cancer attributable to current modifiable causal exposures can guide cancer prevention. Methods We linked pooled data from seven Australian cohort studies (N = 367,058) to national cancer and death registries, and estimated exposure-cancer and exposure-death associations using adjusted proportional hazards models. We estimated exposure prevalence from contemporary national health surveys and calculated population attributable fractions (PAFs) and 95% confidence intervals, using advanced methods accounting for competing risk of death. Results Current levels of past and current smoking explain 36.1% (95%CI 33.2%-38.9%), body fatness 13.6% (10.9%-16.2%) and alcohol consumption exceeding two drinks/day 2.3% (1.0%-3.6%) of cancers causally related to these exposures, corresponding to 210,000, 81,300 and 14,800 cancers in Australia in the next 10 years, respectively. Ever smoking is the leading modifiable cause of lung (82.1%), bladder (49.8%), oesophageal (42.8%), liver (39.8%), head and neck (35.6%), and pancreatic (21.3%) cancer burden. Body fatness is the leading modifiable cause of corpus uteri (42.5%), gastric cardia (33.6%), renal cell (29.1%), thyroid (20.1%), colorectal (12.6%) and postmenopausal breast (12.6%) cancer burden. The absolute numbers of cancers in the next 10 years attributable to smoking are highest for lung cancer (114,000). The numbers of cancers attributable to body fatness and alcohol are highest for colorectal cancer (23,000 and 9,900, respectively). Conclusions More reliable advanced methods demonstrate large proportions and numbers of cancers are preventable by modifying behaviours. Key messages Ever smoking and body fatness are the leading causes of preventable future burden of causally related cancers in Australia.

A significant increase in Tuberculosis diagnosis is required to mitigate the impact of COVID-19 on its future burden

The ongoing COVID-19 pandemic has greatly disrupted our everyday life, forcing the adoption of non-pharmaceutical interventions in many countries worldwide and putting public health services and healthcare systems worldwide under stress. These circumstances are leading to unintended effects such as the increase in the burden of other diseases. Here, using a data-driven epidemiological model for Tuberculosis (TB) spreading, we describe the expected rise in TB incidence and mortality that can be attributable to the impact of COVID-19 on TB surveillance and treatment in four high-burden countries. Our calculations show that the reduction in the diagnosis of new TB cases due to the COVID-19 pandemic could result in 824250 (CI 702416-940873) excess deaths in India, 288064 (CI 245932-343311) in Indonesia, 145872 (CI 120734-171542) in Pakistan, and 37603 (CI 27852-52411) in Kenya. Furthermore, we show that it is possible to revert such unflattering TB burden scenarios by increasing the pre-covid diagnosis capabilities by at least 75% during 2 to 4 years. This would prevent almost all TB-related excess mortality caused by the COVID-19 pandemic, which will be observed if nothing is done to prevent it. Our work, therefore, provides guidelines for mitigating the impact of COVID-19 on tuberculosis epidemic in the years to come.

African families’ and caregivers’ experiences of raising a child with intellectual disability: A narrative synthesis of qualitative studies

Background: The prevalence of intellectual disability was high in Africa, particularly amongst low socio-economic communities. Despite this, there was limited literature on primary caregivers and parents of people with intellectual disabilities regarding their experience raising an individual with the condition, especially within the African context.Objectives: The aim of the current systematic review was to investigate experiences of caregivers and parents of children with intellectual disability in Africa.Method: We used strict eligibility criteria to identify suitable studies. We identified Medical Subject Headings (MeSH) terms and other keyword terms and, after conducting searches in electronic databases, identified articles that met the inclusion criteria for articles published between 1975 and the end of 2019.Results: 164 articles were assessed for eligibility. Nine studies met the review’s criteria. Six major themes emerged: understanding of intellectual disability (ID), worries about the future, burden of care, lack of services, coping strategies and stigma and discrimination.Conclusion: Caregivers of children with intellectual disability in Africa faced substantial challenges. Current findings suggested that there was the need for both formal and alternative healthcare workers to work together towards an understanding and management of intellectual disability in Africa.