The case-cohort design obtains complete covariate data only on cases and on a random sample (the subcohort) of the entire cohort. Subsequent publications described the use of stratification and weight calibration to increase efficiency of estimates of Cox model log-relative hazards, and there has been some work estimating pure risk. Yet there are few examples of these options in the medical literature, and we could not find programs currently online to analyze these various options. We therefore present a unified approach and R software to facilitate such analyses. We used influence functions adapted to the various design and analysis options together with variance calculations that take the two-phase sampling into account. This work clarifies when the widely used \"robust\" variance estimate of Barlow (Biometrics 50:1064-1072, 1994) is appropriate. The corresponding R software, CaseCohortCoxSurvival, facilitates analysis with and without stratification and/or weight calibration, for subcohort sampling with or without replacement. We also allow for phase-two data to be missing at random for stratified designs. We provide inference not only for log-relative hazards in the Cox model, but also for cumulative baseline hazards and covariate-specific pure risks. We hope these calculations and software will promote wider use of more efficient and principled design and analysis options for case-cohort studies.

Landslides are among the most destructive geological disasters that seriously damage human life and infrastructures. Landslides mainly occur in mountainous regions around the world. One of the key processes to reduce these damages is to uncover landslide-exposed areas through different data-driven methods such as Geographical Information System (GIS) and multi-criteria decision-making (MCDM). In the literature, there are many studies developed with these fundamental tools. In this study, unlike the literature, a new landslide susceptibility assessment model is proposed by integrating GIS with the stratified best-worst method (S-BWM). This model has four main dimensions and 16 sub-dimensions under topography, environment-land, location, and hydrological factors, weighted with the S-BWM. A network was created considering the different states that may arise in the importance weights of these dimensions in the future. The transition probabilities of these states were predicted and injected into the classical BWM. Then, maps were created for these dimensions and classifications for each sub-dimension according to the map characteristics. Finally, the most susceptive landslide locations were determined with GIS-based calculations. To demonstrate the model\'s applicability, a case study was conducted for the Erzurum region, one of Turkey\'s landslide-prone regions. In addition, besides the landslide map, an analysis and discussion about the spatial distribution of susceptibility classes was presented, contributing to the study\'s robustness. In the results of landslide susceptibility analysis, landslides are higher in the range of about 1600-2500 m. Approximately 42% (35.59 sq. km) of the study area has high landslide susceptibility, while 58% (64.41 sq. km) has medium and low landslide susceptibility.

Considerable wealth stratification exists between U.S.-born and foreign-born populations (Campbell and Kaufman 2006), with low wealth attainment documented among Mexican immigrants (Hao 2007). High rates of Mexican return migration (Azose and Raftery 2019) suggest that nonrandom selection into return migration on wealth is a potential driver of stratification. Existing theories do not conclusively predict asset accumulation among returnees versus stayers, and empirical research on return migration and wealth stratification is scarce. Combining data from the 2000 U.S. Health and Retirement Study and the 2001 Mexican Health and Aging Study to create a novel data set representing all Mexicans aged 50 and older with a history of migration to the United States and adopting a life course perspective, I find that return migration at younger and older ages is associated with higher wealth accumulation and might be a way to maximize assets at older ages. Thus, return migration may contribute to nativity-based wealth stratification in the United States. The study\'s findings point to the greater financial risks for new cohorts of immigrants aging in place, suggest caution in interpreting wealth stratification as a measure of mobility, and inform theories about the links between return migration and wealth across the life course.

The application of serial principled sampling designs for diagnostic testing is often viewed as an ideal approach to monitoring prevalence and case counts of infectious or chronic diseases. Considering logistics and the need for timeliness and conservation of resources, surveillance efforts can generally benefit from creative designs and accompanying statistical methods to improve the precision of sampling-based estimates and reduce the size of the necessary sample. One option is to augment the analysis with available data from other surveillance streams that identify cases from the population of interest over the same timeframe, but may do so in a highly nonrepresentative manner. We consider monitoring a closed population (e.g., a long-term care facility, patient registry, or community), and encourage the use of capture-recapture methodology to produce an alternative case total estimate to the one obtained by principled sampling. With care in its implementation, even a relatively small simple or stratified random sample not only provides its own valid estimate, but provides the only fully defensible means of justifying a second estimate based on classical capture-recapture methods. We initially propose weighted averaging of the two estimators to achieve greater precision than can be obtained using either alone, and then show how a novel single capture-recapture estimator provides a unified and preferable alternative. We develop a variant on a Dirichlet-multinomial-based credible interval to accompany our hybrid design-based case count estimates, with a view toward improved coverage properties. Finally, we demonstrate the benefits of the approach through simulations designed to mimic an acute infectious disease daily monitoring program or an annual surveillance program to quantify new cases within a fixed patient registry.

We present a case study on the impact of effluent from a wastewater lagoon-wetland system on phytoplankton and local primary production near a coastal Arctic community (Cambridge Bay) over spring to fall 2018. Results are also placed within an interannual and regional context for the surrounding Kitikmeot Sea. We find the shallow, relatively fresh Kitikmeot Sea is one of the most nutrient-deplete regions of the Arctic Ocean with NO3- + NO2- concentrations below the surface mixed layer rarely exceeding 2 μmol L-1 and a N:Si:P ratio of 1:6:1. The fjordal-type bathymetry of the main study site and a persistent pycnocline below the bay\'s exit sill led to slightly elevated N:Si:P of 3:11:1 through trapping of wastewater-sourced N at depth via sinking and remineralization of primary production. Total production in Cambridge Bay over the 3-month open water period was 12.1 g C m-2 with 70% of this production occurring during the 1-month discharge of wastewater into the system. Local primary production responded rapidly to high NO3- + NO2-, NH4+ and PON concentrations provided by wastewater effluent, comprising up to 20% of the production during the discharge period. Remaining production was mostly explained by the deep nutrient pool in the bay, which was only accessed towards the end of the discharge period as the diatom-dominated deep chlorophyll maximum settled below the pycnocline. Although not yet eutrophic, caution is raised at the rapid response of the marine system to wastewater release with a strong recommendation to develop a research and monitoring plan for the bay.

Detailed treatment regimens for patients with chronic obstructive pulmonary disease (COPD) were developed by the Global Initiative for Chronic Obstructive Lung Disease (GOLD). Every few years the method of classification of COPD severity and the treatment recommendations are significantly revised. The aim of this study was to determine the clinical implications of changing GOLD reports (2007-2011-2017) and the impact that these changes would have on pharmacological treatment regimens of patients with COPD. A group of 500 randomly chosen primary care physicians in Poland each provided information on 10 consecutive patients diagnosed with COPD. This data was used to simulate the therapeutic consequences of the update of the GOLD 2007 report to GOLD 2011 and GOLD 2017. Pharmacological treatment algorithms from the GOLD 2007 report prefer the use of inhaled corticosteroids (ICS) and short-acting bronchodilators (60.2% and 50%, respectively). Compared to the GOLD 2007 report, there would be an almost eightfold reduction in the frequency of short-acting bronchodilator using the GOLD 2011 report and over fourfold decrease using the GOLD 2017 report. With each subsequent update of the GOLD report, the frequency of use of ICS would be significantly (p < 0.001) reduced. Pharmacological treatment by the GOLD 2011 and 2017 reports would be dominated by the use of long-acting bronchodilators from the group β2-agonists and muscarinic antagonist groups. Updates from the GOLD 2007 COPD report to GOLD 2011 and 2017 would have a significant impact on everyday clinical practice. Changes would result in a reduction of treatment intensity.

Using a database of recent articles published in the field of Global Health research, we examine institutional sources of stratification in publishing access outcomes. Traditionally, the focus on inequality in scientific publishing has focused on prestige hierarchies in established print journals. This project examines stratification in contemporary publishing with a particular focus on subscription vs. various Open Access (OA) publishing options. Findings show that authors working at lower-ranked universities are more likely to publish in closed/paywalled outlets, and less likely to choose outlets that involve some sort of Article Processing Charge (APCs; gold or hybrid OA). We also analyze institutional differences and stratification in the APC costs paid in various journals. Authors affiliated with higher-ranked institutions, as well as hospitals and non-profit organizations pay relatively higher APCs for gold and hybrid OA publications. Results suggest that authors affiliated with high-ranked universities and well-funded institutions tend to have more resources to choose pay options with publishing. Our research suggests new professional hierarchies developing in contemporary publishing, where various OA publishing options are becoming increasingly prominent. Just as there is stratification in institutional representation between different types of publishing access, there is also inequality within access types.

OBJECTIVE: Research on healthcare disparities is making important descriptive and analytical strides, and the issue of disparities has gained the attention of policymakers in the US, other nation-states, and international organizations. Still, disparities scholarship remains US-centric and too rarely takes a cross-national comparative approach to answering its questions. The US-centricity of disparities research has fostered a fixation on race and ethnicity that, although essential to understanding health disparities in the United States, has truncated the range of questions researchers investigate. In this article, we make a case for comparative research that highlights its ability to identify the institutional factors may affect disparities.
METHODS: We discuss the central methodological challenges to comparative research. After describing current solutions to such problems, we use data from the World Values Survey to show the impact of key social fault lines on self-assessed health in Europe and the U.S.
RESULTS: The negative impact of SES on health is more generalizable across context, than the impact of race/ethnicity or gender.
CONCLUSIONS: Our analysis includes a limited number of countries and relies on one measure of health.
UNASSIGNED: The paper represents a first step in a research agenda to understand health inequalities within and across societies.

Reactive case detection could be a powerful tool in malaria elimination, as it selectively targets transmission pockets. However, field operations have yet to demonstrate under which conditions, if any, reactive case detection is best poised to push a region to elimination. This study uses mathematical modelling to assess how baseline transmission intensity and local interconnectedness affect the impact of reactive activities in the context of other possible intervention packages.
Communities in Southern Province, Zambia, where elimination operations are currently underway, were used as representatives of three archetypes of malaria transmission: low-transmission, high household density; high-transmission, low household density; and high-transmission, high household density. Transmission at the spatially-connected household level was simulated with a dynamical model of malaria transmission, and local variation in vectorial capacity and intervention coverage were parameterized according to data collected from the area. Various potential intervention packages were imposed on each of the archetypical settings and the resulting likelihoods of elimination by the end of 2020 were compared.
Simulations predict that success of elimination campaigns in both low- and high-transmission areas is strongly dependent on stemming the flow of imported infections, underscoring the need for regional-scale strategies capable of reducing transmission concurrently across many connected areas. In historically low-transmission areas, treatment of clinical malaria should form the cornerstone of elimination operations, as most malaria infections in these areas are symptomatic and onward transmission would be mitigated through health system strengthening; reactive case detection has minimal impact in these settings. In historically high-transmission areas, vector control and case management are crucial for limiting outbreak size, and the asymptomatic reservoir must be addressed through reactive case detection or mass drug campaigns.
Reactive case detection is recommended only for settings where transmission has recently been reduced rather than all low-transmission settings. This is demonstrated in a modelling framework with strong out-of-sample accuracy across a range of transmission settings while including methodologies for understanding the most resource-effective allocations of health workers. This approach generalizes to providing a platform for planning rational scale-up of health systems based on locally-optimized impact according to simplified stratification.

BACKGROUND: Older adults at a high risk of falls may be referred to a physical therapist. A physical therapy episode of care is designed for the transition of an older adult from a high fall risk to a moderate to low fall risk. However, these episodes of care are limited in time and duration. There is compelling evidence for the efficacy of group-based exercise classes to address risk, and transitioning an older adult from physical therapy to a group-based program may be an effective way to manage risk through the continuum of care.
OBJECTIVE: The purpose of this study was to translate research findings into a \"real world\" setting, and demonstrate the efficacy of integrating evidence-based fall prevention exercises into pre-existing exercise classes at a senior living facility as a \"proof of concept\" model for future programing.
METHODS: Twenty-four participants aged 65 years and older living in a senior living community and the community were stratified into group-based exercise classes. Cutoff scores from functional outcome measures were used to stratify participants. Exercises from The Otago Exercise Program were implemented into the classes. Functional outcome measures collected included the 10-Meter Walk Test, 30-Second Sit to Stand, and Timed Up and Go (TUG). Number of falls, hospitalizations, and physical therapy episodes of care were also tracked. Data were compared to a control group in a different senior living community that offered classes with similar exercises aimed at improving strength and mobility. The classes were taught by an exercise physiologist and were of equal duration and frequency.
RESULTS: Participants demonstrated significant improvements in all functional outcome measures. TUG mean improved from 13.5 to 10.4 s (p = 0.034). The 30-Second Sit to Stand mean improved from 10.5 to 13.4 (p = 0.002). The 10-Meter Walk Test improved from 0.81 to 0.98 m/s (p < 0.0001). Participants did not experience any falls or hospitalizations, and two participants required physical therapy episodes of care.
CONCLUSIONS: Implementing an evidence-based fall reduction program into a senior living program has a positive effect on strength, balance, fall risk, gait speed, fall rate, hospitalizations, and amount of physical therapy intervention.