Strategies to Increase Response Rate and Reduce Nonresponse Bias in Population Health Research: Analysis of a Series of Randomized Controlled Experiments during a Large COVID-19 Study.

Background: High response rates are needed in population-based studies, as nonresponse reduces effective sample size and bias affects accuracy and decreases the generalizability of the study findings.

Objective: We tested different strategies to improve response rate and reduce nonresponse bias in a national population-based COVID-19 surveillance program in England, United Kingdom.

Methods: Over 19 rounds, a random sample of individuals aged 5 years and older from the general population in England were invited by mail to complete a web-based questionnaire and return a swab for SARS-CoV-2 testing.

The Center for Health Outcomes in Medicine Scholarship and Service (HOMES): Fostering and Supporting Physician-Initiated Research.

ProblemThe U.S. physician scholar workforce, currently comprising less than 1.

A Functional Response in Resource Selection Links Multiscale Responses of a Large Carnivore to Human Mortality Risk.

Theory suggests that animals make hierarchical, multiscale resource selection decisions to address the hierarchy of factors limiting their fitness. Ecologists have developed tools to link population-level resource selection across scales; yet, theoretical expectations about the relationship between coarse- and fine-scale selection decisions at the individual level remain elusive despite their importance to fitness. With GPS-telemetry data collected across California, USA, we evaluated resource selection of mountain lions (Puma concolor; n = 244) relative to spatial variation in human-caused mortality risk.

Intrinsic and environmental drivers of pairwise cohesion in wild Canis social groups.

Animals within social groups respond to costs and benefits of sociality by adjusting the proportion of time they spend in close proximity to other individuals in the group (cohesion). Variation in cohesion between individuals, in turn, shapes important group-level processes such as subgroup formation and fission-fusion dynamics. Although critical to animal sociality, a comprehensive understanding of the factors influencing cohesion remains a gap in our knowledge of cooperative behavior in animals.