A Comparison of Aggregation Methods for Probabilistic Forecasts of COVID-19 Mortality in the United States

The COVID-19 pandemic has placed forecasting models at the forefront of health policy making. Predictions of mortality and hospitalization help governments meet planning and resource allocation challenges. In this paper, we consider the weekly forecasting of the cumulative mortality due to COVID-19 at the national and state level in the U.S. Optimal decision-making requires a forecast of a probability distribution, rather than just a single point forecast. Interval forecasts are also important, as they can support decision making and provide situational awareness. We consider the case where probabilistic forecasts have been provided by multiple forecasting teams, and we aggregate the forecasts to extract the wisdom of the crowd. With only limited information available regarding the historical accuracy of the forecasting teams, we consider aggregation (i.e. combining) methods that do not rely on a record of past accuracy. In this empirical paper, we evaluate the accuracy of aggregation methods that have been previously proposed for interval forecasts and predictions of probability distributions. These include the use of the simple average, the median, and trimming methods, which enable robust estimation and allow the aggregate forecast to reduce the impact of a tendency for the forecasting teams to be under- or overconfident. We use data that has been made publicly available from the COVID-19 Forecast Hub. While the simple average performed well for the high mortality series, we obtained greater accuracy using the median and certain trimming methods for the low and medium mortality series. It will be interesting to see if this remains the case as the pandemic evolves.Comment: 32 pages, 11 figures, 5 table

Contextual Predictors of Hospitalization and Quality of Life among People on Hemodialysis

Background: People on hemodialysis are hospitalized frequently but some are hospitalized more than others. Food insecurity, housing instability, and substance use disorder are risk factors for chronic kidney disease progression that may explain disparities in hospitalization risk among people on hemodialysis. They may also impact health-related quality of life, a patient-reported outcome associated with acute care utilization. Objectives: This dissertation study examined relationships between individual and area-level indicators of socioeconomic position; food insecurity, housing instability, and substance use disorder (framed as contextual risk factors); and hospitalization and quality of life among people on hemodialysis. Methods: We enrolled a convenience sample of 322 people receiving hemodialysis at facilities in the Baltimore and Washington, D.C. metropolitan areas from February through December 2021. Using baseline survey data, we conducted multivariate and mixed effects logistic regression to test associations between (1) individual and area-level indicators of socioeconomic position and (2) food insecurity and housing instability (aim one). Using electronic medical record data from 6 months of study follow up, we applied Cox regression and multivariate linear regression models to test associations between (1) baseline contextual risk factors (i.e., food insecurity, housing instability, or substance use disorder) and (2) hospitalization and quality of life among people on hemodialysis. Results: Over 30% of participants experienced food insecurity in the previous 12 months. 18% reported housing instability. People experiencing food insecurity were more likely to report moderate or high-risk use of tobacco and cannabis or other drugs. Younger age was a risk factor for food insecurity and housing instability. Additionally, residential segregation moderated associations between age, gender, and food security (aim one). Food insecurity, housing instability, and moderate or high-risk substance use were not associated with all-cause hospitalization. However, food insecurity was associated with missed hemodialysis treatments, hospitalizations due to fluid overload or hyperkalemia, and poor kidney disease-related quality of life (aim two). Conclusions: Contextual risk factors, particularly food insecurity, impact health outcomes across the trajectory of chronic kidney disease and are common among people on hemodialysis. Stakeholders can address food insecurity among people on hemodialysis now while health equity research in chronic kidney disease continues

Blood Sugar, Your Pancreas, and Unicorns: The Development of Health Education Materials for Youth With Prediabetes

Background. The obesity epidemic has led to an increase in prediabetes in youth, causing a serious public health concern. Education on diabetes risk and initiation of lifestyle change are the primary treatment modalities. There are few existing age-appropriate health education tools to address diabetes prevention for high-risk youth. Aim. To develop an age-appropriate health education tool(s) to help youth better understand type 2 diabetes risk factors and the reversibility of risk. Method. Health education tool development took place in five phases: exploration, design, analysis, refinement, and process evaluation. Results. The project resulted in (1) booklet designed to increase knowledge of risk, (2) meme generator that mirrors the booklet graphics and allows youth to create their own meme based on their pancreas’ current mood, (3) environmental posters for clinic, and (4) brief self-assessment that acts as a conversation starter for the health educators. Conclusion. Patients reported high likability and satisfaction with the health education tools, with the majority of patients giving the materials an “A” rating. The process evaluation indicated a high level of fidelity and related measures regarding how the health education tools were intended to be used and how they were actually used in the clinic setting

Career progression and destinations, comparing men and women in the NHS: postal questionnaire surveys

Objective To study the career progression of NHS doctors, comparing men and women

Blue-Throated Hummingbird Song: A Pinnacle of Nonoscine Vocalizations

Little is known about the structure and function of hummingbird vocalizations. We studied the vocalizations of Blue-throated Hummingbirds (Lampornis clemenciae) at two sites in southeastern Arizona. Songs were produced by males and females. Male songs consisted of arrays of notes organized in clusters of ‘‘song units.’’ Within sites, all males shared the same song units. Individual differences occurred in some temporal aspects of song, and slight but consistent differences in note structure occurred between the two sites. The organization of units within songs was marked by rigid syntax, and long songs were produced by agglutination of units. Male songs may function in territorial advertisement and mate attraction. Female songs were very different acoustically from those of males and typically were given when females were within a few centimeters of a male. In these situations, the female’s song often overlapped temporally with the male’s song. Of the hummingbird species studied so far, the Blue-throated Hummingbird has the most complex songs and is the only known species with complex female songs. Blue-throated Hummingbirds show convergence with oscines in vocal complexity, song organization, song function, and possible learning of some song elements

Social and Cultural Barriers to Diabetes Prevention in Oklahoma American Indian Women

INTRODUCTION: The prevalence of diabetes is disproportionately higher among minority populations, especially American Indians. Prevention or delay of diabetes in this population would improve quality of life and reduce health care costs. Identifying cultural definitions of health and diabetes is critically important to developing effective diabetes prevention programs. METHODS: In-home qualitative interviews were conducted with 79 American Indian women from 3 tribal clinics in northeast Oklahoma to identify a cultural definition of health and diabetes. Grounded theory was used to analyze verbatim transcripts. RESULTS: The women interviewed defined health in terms of physical functionality and absence of disease, with family members and friends serving as treatment promoters. Conversely, the women considered their overall health to be a personal issue addressed individually without burdening others. The women presented a fatalistic view of diabetes, regarding the disease as an inevitable event that destroys health and ultimately results in death. CONCLUSION: Further understanding of the perceptions of health in at-risk populations will aid in developing diabetes prevention programs

Racial Differences in the Effect of Granulocyte Macrophage Colony-Stimulating Factor on Improved Walking Distance in Peripheral Artery Disease: The PROPEL Randomized Clinical Trial.

Background The effects of race on response to medical therapy in people with peripheral artery disease ( PAD ) are unknown. Methods and Results In the PROPEL (Progenitor Cell Release Plus Exercise to Improve Functional Performance in PAD) Trial, PAD participants were randomized to 1 of 4 groups for 6 months: supervised treadmill exercise+granulocyte-macrophage colony-stimulating factor ( GM - CSF ) (Group 1), exercise+placebo (Group 2), attention control+ GM - CSF (Group 3), or attention control+placebo (Group 4). Change in 6-minute walk distance was measured at 12- and 26-week follow-up. In these exploratory analyses, groups receiving GM - CSF (Groups 1 and 3), placebo (Groups 2 and 4), exercise (Groups 1 and 2), and attention control (Groups 2 and 4) were combined, maximizing statistical power for studying the effects of race on response to interventions. Of 210 PAD participants, 141 (67%) were black and 64 (30%) were white. Among whites, GM - CSF improved 6-minute walk distance by +22.0 m (95% CI : -4.5, +48.5, P=0.103) at 12 weeks and +44.4 m (95% CI : +6.9, +82.0, P=0.020) at 26 weeks, compared with placebo. Among black participants, there was no effect of GM - CSF on 6-minute walk distance at 12-week ( P=0.26) or 26-week (-5.0 m [-27.5, +17.5, P=0.66]) follow-up, compared with placebo. There was an interaction of race on the effect of GM - CSF on 6-minute walk change at 26-week follow-up ( P=0.018). Exercise improved 6-minute walk distance in black ( P=0.006) and white ( P=0.034) participants without interaction. Conclusions GM - CSF improved 6-minute walk distance in whites with PAD but had no effect in black participants. Further study is needed to confirm racial differences in GM - CSF efficacy in PAD . Clinical Trial Registration URL : http://www.clinicaltrials.gov . Unique identifier: NCT 01408901

Dose-Related Estrogen Effects on Gene Expression in Fetal Mouse Prostate Mesenchymal Cells

Developmental exposure of mouse fetuses to estrogens results in dose-dependent permanent effects on prostate morphology and function. Fetal prostatic mesenchyme cells express estrogen receptor alpha (ERα) and androgen receptors and convert stimuli from circulating estrogens and androgens into paracrine signaling to regulate epithelial cell proliferation and differentiation. To obtain mechanistic insight into the role of different doses of estradiol (E2) in regulating mesenchymal cells, we examined E2-induced transcriptomal changes in primary cultures of fetal mouse prostate mesenchymal cells. Urogenital sinus mesenchyme cells were obtained from male mouse fetuses at gestation day 17 and exposed to 10 pM, 100 pM or 100 nM E2 in the presence of a physiological concentration of dihydrotestosterone (0.69 nM) for four days. Gene ontology studies suggested that low doses of E2 (10 pM and 100 pM) induce genes involved in morphological tissue development and sterol biosynthesis but suppress genes involved in growth factor signaling. Genes involved in cell adhesion were enriched among both up-regulated and down-regulated genes. Genes showing inverted-U-shape dose responses (enhanced by E2 at 10 pM E2 but suppressed at 100 pM) were enriched in the glycolytic pathway. At the highest dose (100 nM), E2 induced genes enriched for cell adhesion, steroid hormone signaling and metabolism, cytokines and their receptors, cell-to-cell communication, Wnt signaling, and TGF- β signaling. These results suggest that prostate mesenchymal cells may regulate epithelial cells through direct cell contacts when estrogen level is low whereas secreted growth factors and cytokines might play significant roles when estrogen level is high