Self-reported engagement in exercise is associated with longer event-free survival in heart failure patients with poor functional capacity.

AIMS: Despite evidence-based recommendations for clinically stable patients with heart failure (HF) to engage in unsupervised exercise, the minimum cumulative dose of exercise per week associated with improvement in HF outcomes, especially in patients with poor functional capacity, has not been examined. We examined whether patients with HF and poor functional capacity who reported engagement in a guideline-recommended minimum weekly exercise had longer event-free survival than patients who did not exercise. METHODS AND RESULTS: This analysis included 310 patients with HF who had completed the Duke Activity Status Index (DASI) and reported their level of engagement in exercise. Patients were grouped into good and poor functional capacity using a DASI cut-point of ≥19 and then further stratified based on their self-reported exercise level: high (≥60 min/week) and low (<60 min/week). Cox regression modelling was used to predict event-free survival for the four groups after adjusting for covariates. Patients (mean age = 61.6 ± 11.4 years, 30.3% female, 44.2% NYHA Classes III-IV) were followed for a median of 362 days. There were eight deaths and 108 all-cause hospitalizations. Patients with poor functional capacity who reported high exercise engagement had a 36% lower risk of all-cause hospitalization or mortality compared with patients with poor functional capacity who reported low exercise engagement (hazard ratio: 0.64, P = 0.028). CONCLUSION: Self-reported engagement in a minimum of 60 min of exercise per week was associated with a significant improvement in event-free survival, even in patients with HF with low functional capacity. These results provide evidence that this dose of exercise is beneficial in patients with HF and poor functional capacity.

Making Space in Geographical Analysis.

In this commentary we reflect on the potential and power of geographical analysis, as a set of methods, theoretical approaches, and perspectives, to increase our understanding of how space and place matter for all. We emphasize key aspects of the field, including accessibility, urban change, and spatial interaction and behavior, providing a high-level research agenda that indicates a variety of gaps and routes for future research that will not only lead to more equitable and aware solutions to local and global challenges, but also innovative and novel research methods, concepts, and data. We close with a set of representation and inclusion challenges to our discipline, researchers, and publication outlets.

Mask Effectiveness for Preventing Secondary Cases of COVID-19, Johnson County, Iowa, USA.

In September of 2020, the Iowa Department of Public Health released guidance stating that persons exposed to someone with coronavirus disease (COVID-19) need not quarantine if the case-patient and the contact wore face masks at the time of exposure. This guidance differed from that issued by the Centers for Disease Control and Prevention. To determine the best action, we matched exposure information from COVID-19 case investigations with reported test results and calculated the secondary attack rates (SARs) after masked and unmasked exposures. Mask use by both parties reduced the SAR by half, from 25.6% to 12.5%. Longer exposure duration significantly increased SARs. Masks significantly reduced virus transmission when worn by both the case-patient and the contact, but SARs for each group were higher than anticipated. This finding suggests that quarantine after COVID-19 exposure is beneficial even if parties wore masks.

Contact tracing for the control of infectious disease epidemics: Chronic Wasting Disease in deer farms.

Contact tracing is a crucial component of the control of many infectious diseases, but is an arduous and time consuming process. Procedures that increase the efficiency of contact tracing increase the chance that effective controls can be implemented sooner and thus reduce the magnitude of the epidemic. We illustrate a procedure using Graph Theory in the context of infectious disease epidemics of farmed animals in which the epidemics are driven mainly by the shipment of animals between farms. Specifically, we created a directed graph of the recorded shipments of deer between deer farms in Pennsylvania over a timeframe and asked how the properties of the graph could be exploited to make contact tracing more efficient should Chronic Wasting Disease (a prion disease of deer) be discovered in one of the farms. We show that the presence of a large strongly connected component in the graph has a significant impact on the number of contacts that can arise.