PCR, Tropical Arithmetic, and Group Testing

Polymerase chain reaction (PCR) testing is the gold standard for diagnosing COVID-19. Unfortunately, the outputs of these tests are imprecise and therefore quantitative group testing methods, which rely on precise measurements, are not applicable. Motivated by the ever-increasing demand to identify individuals infected with SARS-CoV-19, we propose a new model that leverages tropical arithmetic to characterize the PCR testing process. In many cases, some of which are highlighted in this work, tropical group testing is provably more powerful than traditional binary group testing in that it requires fewer tests than classical approaches, while additionally providing a mechanism to identify the viral load of each infected individual. © 2022 IEEE.

View from the Patient Perspective: Mixed-Methods Analysis of Post-Discharge Virtual Visits in a Randomized Controlled Trial

BACKGROUND: Virtual visits (VVs) are being used increasingly to provide patient-centered care and have un-dergone rapid uptake during the COVID-19 pandemic. Our aim was to compare satisfaction and convenience of virtual post-discharge follow-up for surgical patients and qualitatively analyze free-text survey responses in a randomized controlled noninferiority trial. Patient satisfaction with VVs has not been evaluated previously in a randomized controlled trial and few mixed-methods an-alyses have been done to understand barriers and facilitators to post-discharge visits. STUDY DESIGN: Patients undergoing laparoscopic appendectomy or cholecystectomy were randomized to VV or in-person visit (2:1). Surveys with 11 multiple-choice and 2 open-ended questions eval-uated patient satisfaction and convenience. Univariate analysis compared responses to the multiple-choice questions and qualitative content analysis evaluated open-ended responses. RESULTS: Of 442 enrolled patients, 289 completed their postoperative visit and were sent surveys (55% response rate). Patients were categorized as VV (n = 135), crossover (randomized to virtual but completed in-person;n = 53), and in-person visits (n = 101). Patient-reported satisfaction was similar, but convenience was higher for VV patients. Open-ended responses (72 VVs, 14 crossovers, and 41 in-person visits) were qualitatively analyzed. In all groups, patient experience was influenced by quality of care, efficiency, and convenience. Barriers were different for virtual and in-person appointments. CONCLUSIONS: We found that quality of, and access to, care-whether in person or virtualdremained critical components of patient satisfaction. VVs address many barriers associated with in-person visits and were more convenient, but can present additional technological barriers. (C) 2021 by the American College of Surgeons. Published by Elsevier Inc. All rights reserved.

[The differential diagnosis for novel coronavirus pneumonia and similar lung diseases in general hospitals].

Novel coronavirus pneumonia was a novel coronavirus infection that has dominated pulmonary infection since December 2019. The main manifestations were fever, dry cough, shortness of breath, normal or leukopenia in peripheral blood and changes in chest CT and in severe cases, multiple organ failure might occur. The National Health Commission, PRC has revised the consensus on diagnosis and treatment seven times in a short period of time, indicating the growing understanding of the disease. Patients with novel coronavirus pneumonia usually had history of travelling or living in the epidemic area including Wuhan within 14 days before onset, or have been exposed to patients who had fever or respiratory symptoms from the epidemic area, or had clustering diseases. However, novel coronavirus pneumonia was becoming more and more blurred after vanishing epidemic. The diagnosis and differential diagnosis of novel coronavirus pneumonia were challenges not only because of large number of tourists increasing dramatically after the relieving of epidemic, but also patients with other diseases from different areas to search for medical care. In this article, the clinical and chest imaging features of the novel coronavirus pneumonia were reviewed and compared with other infections and non-infectious diffuse pulmonary diseases. We try to find the similarities and differences among them, and to identify clues to the diagnosis of novel coronavirus pneumonia, so as to ensure accurate diagnosis and treatment.