Six-Month Mortality among HIV-Infected Adults Presenting for Antiretroviral Therapy with Unexplained Weight Loss, Chronic Fever or Chronic Diarrhea in Malawi.

In sub-Saharan Africa, early mortality is high following initiation of antiretroviral therapy (ART). We investigated 6-month outcomes and factors associated with mortality in HIV-infected adults being assessed for ART initiation and presenting with weight loss, chronic fever or diarrhea, and with negative TB sputum microscopy

Postextubation pulmonary edema: A case series and review

SummaryWe report a series of patients with postextubation pulmonary edema who had no obvious risk factors for the development of this syndrome.MethodsPatients identified by the pulmonary consultation service at an academic medical center were reviewed.ResultsFourteen cases were collected and analyzed. The average age was 34.5 years; 12 patients were male. The average BMI was 25.5. None had documented previous lung disease. Most operations were scheduled as outpatient procedures, and the type of surgery ranged from an incision and drainage of a bite wound to an open reduction- internal fixation of the radius. None of the patients had upper airway surgery. The length of surgeries ranged from 27 to 335min. Laryngospasm was the most commonly identified obstructing event postextubation. Treatment involved airway support when needed, supplemental oxygen, and diuretics.ConclusionsIt would appear that all patients, especially young men, are at risk for the development of this syndrome and that the pathogenesis remains uncertain in many cases

Optimal Time Allocation between Idle and Active Time

Idle time is an essential and valuable factor in the production of any service. While idle time is necessary and helpful for efficient and effective utilization of time, it also has a negative effect that managers try to minimize. This paper illustrates either analytically or numerically the different effects of idle time on total net revenue. It first presents the case in which idle time is determined arbitrarily, and then shows idle time that has no direct negative effect on total revenue but a positive effect on the efficient use of active time

Number (of Whom?) Needed to Treat (with What?): Exposures, Population Interventions, and the Number Needed to Treat

The number needed to treat (NNT) is a widely used measure of the potential impact of a treatment or intervention, but it is often calculated and discussed in ways which oversimplify critical issues. Specifically, the NNT itself depends on the population under study and the specific form that "treatment" would take in that population. We discuss how understanding the difference between the effect of removing a harmful exposure and the effect of deploying a specific intervention to remove that harmful exposure can affect the calculation and interpretation of an NNT. Our discussion extends a previously described framework distinguishing exposure effects from population intervention effects

Editorial: Innovations in Study Design - A Call for Creative Solutions

Epidemiology is maturing as a discipline, with increasingly standardized approaches to how we design studies to answer questions of scientific, clinical, and public health interest. Over time, the repertoire changes, and it is likely to continue to evolve for both technological and methodological reasons. With regard to the former, approaches change because of both the phase-out of older technologies (such as a move away from telephone surveys as patterns of phone coverage and usage shifted) and the introduction of new technologies (such as the utilization of novel environmental data through satellite mapping or of the rapidly evolving ways of collecting real-time assessment of exposure and health status from smart phone users). The latter category includes both methodological innovations (such as increased reliance on nested studies) and the recognition of methodological flaws in older methods (such as the gradual abandonment of hospital-based case-control studies)

UK Biobank, big data, and the consequences of non-representativeness

UK Biobank is an unparalleled resource of extensive health information from 500 000 individuals and with more than 400 peer-reviewed publications to date. The sampling population is volunteer-based and is not representative of the UK population. Investigators state that although the estimates of prevalence and incidence should be interpreted with caution, valid measures of association and estimates of causal effect can be more readily interpreted as they do “not require participants to be representative of the population at large”

TWO STUDY DESIGNS WALK INTO A BAR...

A randomized controlled trial and a regression discontinuity design, out for a causal stroll together, duck into the Potential Outcomes Tavern and step up to the factual counter

Group testing for severe acute respiratory syndrome-coronavirus 2 to enable rapid scale-up of testing and real-time surveillance of incidence

High-throughput molecular testing for severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) may be enabled by group testing in which pools of specimens are screened, and individual specimens tested only after a pool tests positive. Several laboratories have recently published examples of pooling strategies applied to SARS-CoV-2 specimens, but overall guidance on efficient pooling strategies is lacking. Therefore we developed a model of the efficiency and accuracy of specimen pooling algorithms based on available data on SAR-CoV-2 viral dynamics. For a fixed number of tests, we estimate that programs using group testing could screen 2-20 times as many specimens compared with individual testing, increase the total number of true positive infections identified, and improve the positive predictive value of results. We compare outcomes that may be expected in different testing situations and provide general recommendations for group testing implementation. A free, publicly-available Web calculator is provided to help inform laboratory decisions on SARS-CoV-2 pooling algorithms

To Contact Tracing... And Beyond!

To the Editor—We write to endorse and extend the thoughts of Nosyk et al on contact tracing, which we strongly agree is an opportunity to achieve additional public health goals, including diagnosis, treatment, and prevention of human immunodeficiency virus (HIV)

Thirteen Questions about Using Machine Learning in Causal Research (You Won't Believe the Answer to Number 10!)

Machine learning is gaining prominence in the health sciences, where much of its use has focused on datadriven prediction. However, machine learning can also be embedded within causal analyses, potentially reducing biases arising from model misspecification. Using a question-and-answer format, we provide an introduction and orientation for epidemiologists interested in using machine learning but concerned about potential bias or loss of rigor due to use of "black box"models. We conclude with sample software code that may lower the barrier to entry to using these techniques