A Step-by-Step Guide to Selecting an Optimal Cut-Off Value Based on the Receiver Operating Characteristic and Youden Index in Methods Designed to Diagnose Lyme Disease.

Detection tools designed to diagnose complex diseases such as Lyme Borreliosis require an optimal cutoff point to distinguish the healthy from the diseased. The chapter will provide a practical guide to selecting an optimal cutoff mark by creating the receiver operating characteristic (ROC) in Microsoft Excel. To guide the creation of a ROC graphical plot, we will use example data from an enzyme-linked immunosorbent assay (ELISA) measuring anti-human immunoglobulin G (IgG) against whole-cell Borrelia lysates. Herein, the ROC method will demonstrate that an optical density (OD) value from ELISA with the highest Youden Index (J) is an optimal cutoff value to differentiate positive and negative IgG immune responses in human serum samples.

SARSPLEX: Multiplex Serological ELISA with a Holistic Approach.

Currently, there are over 602 million severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases and 6.4 million COVID-19 disease-related deaths worldwide. With ambitious vaccine strategies, reliable and accurate serological testing is needed to monitor the dynamics of the novel coronavirus pandemic and community immunity. We set out to improve serological testing of the immune response against SARS-CoV-2. We hypothesize that by multiplexing the serological diagnostic test kit (SARSPLEX) and screening for three antibodies, an even more robust diagnostic can be developed. A total of 293 sera were analyzed for IgM, IgG, or IgA immune reactions to the subunit 1 spike glycoprotein and the nucleocapsid protein in a standardized ELISA platform. Testing IgM, IgG, and IgA demonstrated high positive and negative agreements compared to RT-PCR and serology reference tests. Comparison with the pre-2019-CoV (n = 102) samples highlighted the specificity of this test kit and indicated that no unspecific binding, even with the summer flu patients (n = 44), was detected. In addition, SARSPLEX demonstrated to be a valuable occupational surveillance tool used in a functional medicine facility. With increased and broader testing, SARSPLEX will be a valuable tool in monitoring immunity and aid in prioritizing access to the SARS-CoV-2 vaccine for high-risk patients.

Supporting Engagement, Adherence, and Behavior Change in Online Dietary Interventions.

INTRODUCTION: Poor diet is a leading cause of death and disease globally. This epidemic requires effective and accessible interventions to stop the increasing number of diet-related deaths and the health and economic impacts of diet-related disease. Online interventions provide flexibility and accessibility. With the ubiquitous use of smartphones, they can be intertwined with daily activities such as shopping and eating. The aim of this review is to determine what features and behavior change techniques employed in online dietary interventions for adult populations promoting dietary behavior change. METHODS: The researchers conducted a systematic search of Cumulative Index of Nursing and Allied Health, Cochrane Library, Global Health, MEDLINE, PsychINFO, and psychological and behavioral sciences electronic bibliography databases, and specialist electronic health (e-health) journals from database inception to January, 2018. Studies were included if they were randomized controlled trials of online dietary interventions with active comparator conditions in adult populations, and with reported dietary change measures. A quality score was applied to each study calculated by a developed scoring system. The review analyzed intervention dietary change measures, attrition (nonuse and dropout), engagement (metrics and intensity of use), adherence (defined as compliance to the treatment protocol), behavior change techniques employed to achieve dietary change, and techniques employed in successful (those who achieved significant results in the targeted dietary behavior) vs unsuccessful interventions as reported by the studies. RESULTS: A total of 21 studies composed of a total of 7,455 adults and reporting on 19 different e-health interventions were included from 1,237 records. These studies targeted dietary change as measured by reduced energy intake (5) or changes in specific dietary components (15) and overall diet quality (4). Dietary change was a behavior target in general healthy populations (12) and for managing diseases such as obesity and cardiovascular disease (7), or for improving quality of life for those with chronic conditions (1). Improvements in dietary behavior were seen in 14 of the 19 interventions reported. DISCUSSION: The results suggest that online interventions can be successful in achieving dietary behavior change across a range of defined populations. However, disparate reporting of engagement and limited reporting of nonuse attrition rates limited the analysis of which behavior change techniques were most effective in achieving this change. IMPLICATIONS FOR RESEARCH AND PRACTICE: The results of this review support the potential of online and smartphone dietary interventions as a method to achieve change in diet in defined populations. However, further work needs to be done in examining how users engage with interventions, and thus which behavior change techniques are most effective.