Looking under the lamp-post: quantifying the performance of contact tracing in the United States during the SARS-CoV-2 pandemic.

Contact tracing forms a crucial part of the public-health toolbox in mitigating and understanding emergent pathogens and nascent disease outbreaks. Contact tracing in the United States was conducted during the pre-Omicron phase of the ongoing COVID-19 pandemic. This tracing relied on voluntary reporting and responses, often using rapid antigen tests due to lack of accessibility to PCR tests. These limitations, combined with SARS-CoV-2's propensity for asymptomatic transmission, raise the question "how reliable was contact tracing for COVID-19 in the United States"? We answered this question using a Markov model to examine the efficiency with which transmission could be detected based on the design and response rates of contact tracing studies in the United States. Our results suggest that contact tracing protocols in the U.S. are unlikely to have identified more than 1.65% (95% uncertainty interval: 1.62-1.68%) of transmission events with PCR testing and 1.00% (95% uncertainty interval 0.98-1.02%) with rapid antigen testing. When considering a more robust contact tracing scenario, based on compliance rates in East Asia with PCR testing, this increases to 62.7% (95% uncertainty interval: 62.6-62.8%). We did not assume presence of asymptomatic transmission or superspreading, making our estimates upper bounds on the actual percentages traced. These findings highlight the limitations in interpretability for studies of SARS-CoV-2 disease spread based on U.S. contact tracing and underscore the vulnerability of the population to future disease outbreaks, for SARS-CoV-2 and other pathogens.

Causal relationships between pain, medical treatments, and knee osteoarthritis: A graphical causal model to guide analyses.

OBJECTIVE: Randomized controlled trials (RCTs) are a gold standard for estimating the benefits of clinical interventions, but their decision-making utility can be limited by relatively short follow-up time. Longer-term follow-up of RCT participants is essential to support treatment decisions. However, as time from randomization accrues, loss to follow-up and competing events can introduce biases and require covariate adjustment even for intention-to-treat effects. We describe a process for synthesizing expert knowledge and apply this to long-term follow-up of an RCT of treatments for meniscal tears in patients with knee osteoarthritis (OA). METHODS: We identified 2 post-randomization events likely to impact accurate assessment of pain outcomes beyond 5 years in trial participants: loss to follow-up and total knee replacement (TKR). We conducted literature searches for covariates related to pain and TKR in individuals with knee OA and combined these with expert input. We synthesized the evidence into graphical models. RESULTS: We identified 94 potential covariates potentially related to pain and/or TKR among individuals with knee OA. Of these, 46 were identified in the literature review and 48 by expert panelists. We determined that adjustment for 50 covariates may be required to estimate the long-term effects of knee OA treatments on pain. CONCLUSION: We present a process for combining literature reviews with expert input to synthesize existing knowledge and improve covariate selection. We apply this process to the long-term follow-up of a randomized trial and show that expert input provides additional information not obtainable from literature reviews alone.

Comparative Effectiveness of Dynamic Treatment Strategies for Medication Use and Dosage: Emulating a Target Trial Using Observational Data.

BACKGROUND: Availability of detailed data from electronic health records (EHRs) has increased the potential to examine the comparative effectiveness of dynamic treatment strategies using observational data. Inverse probability (IP) weighting of dynamic marginal structural models can control for time-varying confounders. However, IP weights for continuous treatments may be sensitive to model choice. METHODS: We describe a target trial comparing strategies for treating anemia with darbepoetin in hemodialysis patients using EHR data from the UK Renal Registry 2004 to 2016. Patients received a specified dose (microgram/week) or did not receive darbepoetin. We compared 4 methods for modeling time-varying treatment: (A) logistic regression for zero dose, standard linear regression for log dose; (B) logistic regression for zero dose, heteroscedastic linear regression for log dose; (C) logistic regression for zero dose, heteroscedastic linear regression for log dose, multinomial regression for patients who recently received very low or high doses; and (D) ordinal logistic regression. RESULTS: For this dataset, method (C) was the only approach that provided a robust estimate of the mortality hazard ratio (HR), with less-extreme weights in a fully weighted analysis and no substantial change of the HR point estimate after weight truncation. After truncating IP weights at the 95th percentile, estimates were similar across the methods. CONCLUSIONS: EHR data can be used to emulate target trials estimating the comparative effectiveness of dynamic strategies adjusting treatment to evolving patient characteristics. However, model checking, monitoring of large weights, and adaptation of model strategies to account for these is essential if an aspect of treatment is continuous.

Looking under the lamp-post: quantifying the performance of contact tracing in the United States during the SARS-CoV-2 pandemic.

Contact tracing forms a crucial part of the public-health toolbox in mitigating and understanding emergent pathogens and nascent disease outbreaks. Contact tracing in the United States was conducted during the pre-Omicron phase of the ongoing COVID-19 pandemic. This tracing relied on voluntary reporting and responses, often using rapid antigen tests (with a high false negative rate) due to lack of accessibility to PCR tests. These limitations, combined with SARS-CoV-2's propensity for asymptomatic transmission, raise the question "how reliable was contact tracing for COVID-19 in the United States"? We answered this question using a Markov model to examine the efficiency with which transmission could be detected based on the design and response rates of contact tracing studies in the United States. Our results suggest that contact tracing protocols in the U.S. are unlikely to have identified more than 1.65% (95% uncertainty interval: 1.62%-1.68%) of transmission events with PCR testing and 0.88% (95% uncertainty interval 0.86%-0.89%) with rapid antigen testing. When considering an optimal scenario, based on compliance rates in East Asia with PCR testing, this increases to 62.7% (95% uncertainty interval: 62.6%-62.8%). These findings highlight the limitations in interpretability for studies of SARS-CoV-2 disease spread based on U.S. contact tracing and underscore the vulnerability of the population to future disease outbreaks, for SARS-CoV-2 and other pathogens.

Preconception Periodontitis and Risk of Spontaneous Abortion in a Prospective Cohort Study.

Few studies have evaluated the association between periodontitis and spontaneous abortion (SAB), and all had limitations. We used data from the Pregnancy Study Online (PRESTO), a prospective preconception cohort study of 3,444 pregnancy planners in the United States and Canada (2019-2022), to address this question. Participants provided self-reported data on periodontitis diagnosis, treatment, and symptoms of severity (i.e., loose teeth) via the enrollment questionnaire. SAB (pregnancy loss at <20 weeks' gestation) was assessed via bimonthly follow-up questionnaires. Participants contributed person-time from the date of a positive pregnancy test to the gestational week of SAB, loss to follow-up, or 20 weeks' gestation, whichever came first. We fitted Cox regression models with weeks of gestation as the time scale to estimate adjusted hazard ratios (HRs) and 95% confidence intervals (CIs), and we used inverse probability of treatment weighting to account for differential loss to follow-up. We used probabilistic quantitative bias analysis to estimate the magnitude and direction of the effect of exposure misclassification bias on results. In weighted multivariable models, we saw no appreciable association between preconception periodontitis diagnosis (HR = 0.97, 95% CI: 0.76, 1.23) or treatment (HR = 1.01, 95% CI: 0.79, 1.27) and SAB. A history of loose teeth was positively associated with SAB (HR = 1.38, 95% CI: 0.88, 2.14). Quantitative bias analysis indicated that our findings were biased towards the null but with considerable uncertainty in the bias-adjusted results.

A randomized trial of web-based fertility-tracking software and fecundability.

OBJECTIVE: To assess the effect of randomization to FertilityFriend.com, a mobile computing fertility-tracking app, on fecundability. DESIGN: Parallel non-blinded randomized controlled trial nested within the Pregnancy Study Online (PRESTO), a North American preconception cohort. PATIENT(S): Female participants aged 21 to 45 years attempting conception for ≤6 menstrual cycles at enrolment (2013-2019). INTERVENTION: Randomization (1:1) of 5532 participants to receive a premium Fertility Friend (FF) subscription. MAIN OUTCOME MEASURE(S): Fecundability (per-cycle probability of conception). Participants completed bimonthly follow-up questionnaires until pregnancy or a censoring event, whichever came first. We first performed an intent-to-treat analysis of the effect of FF randomization on fecundability. In secondary analyses, we used a per-protocol approach that accounted for adherence in each trial arm. In both analyses, we used proportional probabilities regression models to estimate fecundability ratios (FR) and 95% confidence intervals (CI) comparing those randomized vs. not randomized and applied inverse probability weights to account for loss-to-follow-up (intent-to-treat and per-protocol analyses) and adherence (per-protocol analyses only). RESULTS: Using life-table methods, 64% of the 2775 participants randomized to FF and 63% of the 2767 participants not randomized to FF conceived during 12 cycles; these respective percentages were each 70% among those with 0-1 cycles of attempt time at enrolment. Of those randomized to FF, 72% were defined as adherent (68% of observed menstrual cycles). In intent-to-treat analyses, there was no appreciable association overall (FR = 0.97; 95% CI, 0.90-1.04) or within strata of pregnancy attempt time at enrolment, age, education, or other characteristics. In per-protocol analyses, we observed little association overall (FR = 1.06; 95% CI, 0.99-1.14), but weak-to-moderate positive associations among participants who had longer attempt times at enrolment (FR = 1.15; 95% CI, 0.98-1.35 for 3-4 cycles; FR = 1.14; 95% CI, 0.87-1.48 for 5-6 cycles), were aged <25 years (FR = 1.29; 95% CI, 1.01-1.66), had ≤12 years of education (FR = 1.32; 95% CI, 0.92-1.89), or were non-users of hormonal contraception within 3 months before enrolment (FR = 1.10; 95% CI, 1.02-1.19). CONCLUSION: No appreciable associations were observed in intent-to-treat analyses. In secondary per-protocol analyses that accounted for adherence, randomization to FF was associated with slightly greater fecundability among selected subgroups of participants; however, these results are susceptible to unmeasured confounding.

Emulating Target Trials to Avoid Immortal Time Bias - An Application to Antibiotic Initiation and Preterm Delivery.

BACKGROUND: Randomized trials in pregnancy are extremely challenging, and observational studies are often the only option to evaluate medication safety during pregnancy. However, such studies are often susceptible to immortal time bias if treatment initiation occurs after time zero of follow-up. We describe how emulating a sequence of target trials avoids immortal time bias and apply the approach to estimate the safety of antibiotic initiation between 24 and 37 weeks gestation on preterm delivery. METHODS: The Tsepamo Study captured birth outcomes at hospitals throughout Botswana from 2014 to 2021. We emulated 13 sequential target trials of antibiotic initiation versus no initiation among individuals presenting to care <24 weeks, one for each week from 24 to 37 weeks. For each trial, eligible individuals had not previously initiated antibiotics. We also conducted an analysis susceptible to immortal time bias by defining time zero as 24 weeks and exposure as antibiotic initiation between 24 and 37 weeks. We calculated adjusted risk ratios (RR) and 95% confidence intervals (CI) for preterm delivery. RESULTS: Of 111,403 eligible individuals, 17,009 (15.3%) initiated antibiotics between 24 and 37 weeks. In the sequence of target trials, RRs (95% CIs) ranged from 1.04 (0.90, 1.19) to 1.24 (1.11, 1.39) (pooled RR: 1.11 [1.06, 1.15]). In the analysis susceptible to immortal time bias, the RR was 0.90 (0.86, 0.94). CONCLUSIONS: Defining exposure as antibiotic initiation at any time during follow-up after time zero resulted in substantial immortal time bias, making antibiotics appear protective against preterm delivery. Conducting a sequence of target trials can avoid immortal time bias in pregnancy studies.

Implementation of a Device Briefing Tool reduces interruptions in surgery: A nonrandomized controlled pilot trial.

BACKGROUND: Interruptions in operative flow are known to increase team stress and errors in the operating room. Device-related interruptions are an increasing area of focus for surgical safety, but common safety processes such as the Surgical Safety Checklist do not adequately address surgical devices. We assessed the impact of the Device Briefing Tool, a communication instrument for surgical teams, on device-related interruptions in a large academic referral center in Singapore. METHODS: The Device Briefing Tool was implemented in 4 general surgery departments, with 4 additional departments serving as a comparator group. Trained observers evaluated device-related interruption incidence in live operations at baseline and after implementation. Changes in device-related interruption frequency were assessed in each group using Poisson regression, with and without adjustment for surgical department and device complexity. Subgroup analyses assessed the impact of the Device Briefing Tool by device type. RESULTS: A total of 210 operations were evaluated by observers. In the Device Briefing Tool group, there were 38.6 and 27.2 device-related interruptions per 100 cases at baseline and after Device Briefing Tool implementation, respectively (difference -23%, P = .0047, adjusted difference -28%, P = .0013). Device-related interruption frequency in the comparator group remained stable across study periods. Point estimates indicated reductions in device-related interruptions for all device types, reaching statistical significance for circular staplers (-26%, P = .0049). CONCLUSION: Implementation of the Device Briefing Tool was associated with a 28% reduction in device-related interruptions. Proactive approaches to improving surgical device safety are crucial in the technology-driven landscape of modern surgical care. Future efforts will assess formal integration of the Device Briefing Tool into institution-wide surgical safety processes.

Could oral health care professionals help increase human papillomavirus vaccination rates by engaging patients in discussions?

BACKGROUND: Oral health care professionals are well positioned to contribute to the prevention of human papillomavirus (HPV)-related oropharyngeal and other HPV-related cancers through engaging patients in conversations about HPV vaccination. This scoping review evaluates evidence regarding oral health care provider knowledge of, and discussion related to, HPV prevention, transmission, and associated risks, including oropharyngeal cancer. This review outlines relevant barriers to, and facilitators of, this knowledge and discussion. In addition, to determine the potential population that could be reached by an oral health care provider for a conversation about HPV vaccination, this review evaluates the prevalence of HPV vaccination as well as dental visits in a US population. TYPES OF STUDIES REVIEWED: Four databases were systematically searched (MEDLINE [PubMed], EMBASE, APA PsycInfo, Cumulative Index to Nursing and Allied Health Literature). Studies written in English and conducted in the United States were eligible. Eligibility criteria were not restricted to publication year or oral health care provider type. Behavioral Risk Factor Surveillance System 2018 data were analyzed to evaluate the prevalence of HPV vaccination and dental visits among patients aged 18 through 49 years. RESULTS: After duplicate record removal and second-stage screening, 32 full-text articles were retrieved, and data were independently extracted by 2 reviewers. Twenty-four studies were included in this review. Knowledge regarding HPV prevalence, transmission, disease processes, and risks varied. In general, discussions related to HPV in dental settings were infrequent. Facilitators to improve knowledge and discussion included guidance from professional dental organizations, education, and communication skills. Behavioral Risk Factor Surveillance System data showed that most people who are not vaccinated have visited their oral health care providers in the past year, highlighting the potential role of oral health care providers regarding discussion of HPV and promoting awareness and acceptance of vaccination. CONCLUSIONS AND PRACTICAL IMPLICATIONS: This review indicates that discussions related to HPV were infrequent in the oral health care setting, which may be related to lack of knowledge and communication skills among oral health care professionals; however, evidence exists supporting the interest of oral health care professionals in improving vaccine uptake to prevent oropharyngeal cancer.

Lifting Universal Masking in Schools - Covid-19 Incidence among Students and Staff.

BACKGROUND: In February 2022, Massachusetts rescinded a statewide universal masking policy in public schools, and many Massachusetts school districts lifted masking requirements during the subsequent weeks. In the greater Boston area, only two school districts - the Boston and neighboring Chelsea districts - sustained masking requirements through June 2022. The staggered lifting of masking requirements provided an opportunity to examine the effect of universal masking policies on the incidence of coronavirus disease 2019 (Covid-19) in schools. METHODS: We used a difference-in-differences analysis for staggered policy implementation to compare the incidence of Covid-19 among students and staff in school districts in the greater Boston area that lifted masking requirements with the incidence in districts that sustained masking requirements during the 2021-2022 school year. Characteristics of the school districts were also compared. RESULTS: Before the statewide masking policy was rescinded, trends in the incidence of Covid-19 were similar across school districts. During the 15 weeks after the statewide masking policy was rescinded, the lifting of masking requirements was associated with an additional 44.9 cases per 1000 students and staff (95% confidence interval, 32.6 to 57.1), which corresponded to an estimated 11,901 cases and to 29.4% of the cases in all districts during that time. Districts that chose to sustain masking requirements longer tended to have school buildings that were older and in worse condition and to have more students per classroom than districts that chose to lift masking requirements earlier. In addition, these districts had higher percentages of low-income students, students with disabilities, and students who were English-language learners, as well as higher percentages of Black and Latinx students and staff. Our results support universal masking as an important strategy for reducing Covid-19 incidence in schools and loss of in-person school days. As such, we believe that universal masking may be especially useful for mitigating effects of structural racism in schools, including potential deepening of educational inequities. CONCLUSIONS: Among school districts in the greater Boston area, the lifting of masking requirements was associated with an additional 44.9 Covid-19 cases per 1000 students and staff during the 15 weeks after the statewide masking policy was rescinded.

Spillover benefit of pre-exposure prophylaxis for HIV prevention: evaluating the importance of effect modification using an agent-based model.

We developed an agent-based model using a trial emulation approach to quantify effect measure modification of spillover effects of pre-exposure prophylaxis (PrEP) for HIV among men who have sex with men (MSM) in the Atlanta-Sandy Springs-Roswell metropolitan area, Georgia. PrEP may impact not only the individual prescribed, but also their partners and beyond, known as spillover. We simulated a two-stage randomised trial with eligible components (≥3 agents with ≥1 HIV+ agent) first randomised to intervention or control (no PrEP). Within intervention components, agents were randomised to PrEP with coverage of 70%, providing insight into a high PrEP coverage strategy. We evaluated effect modification by component-level characteristics and estimated spillover effects on HIV incidence using an extension of randomisation-based estimators. We observed an attenuation of the spillover effect when agents were in components with a higher prevalence of either drug use or bridging potential (if an agent acts as a mediator between ≥2 connected groups of agents). The estimated spillover effects were larger in magnitude among components with either higher HIV prevalence or greater density (number of existing partnerships compared to all possible partnerships). Consideration of effect modification is important when evaluating the spillover of PrEP among MSM.

Utility of a Device Briefing Tool to Improve Surgical Safety.

INTRODUCTION: Clear communication around surgical device use is crucial to patient safety. We evaluated the utility of the Device Briefing Tool (DBT) as an adjunct to the Surgical Safety Checklist. METHODS: A nonrandomized, controlled pilot of the DBT was conducted with surgical teams at an academic referral center. Intervention departments used the DBT in all cases involving a surgical device for 10 wk. Utility, relative advantage, and implementation effectiveness were evaluated via surveys. Trained observers assessed adherence and team performance using the Oxford NOTECHS system. RESULTS: Of 113 individuals surveyed, 91 responded. Most respondents rated the DBT as moderately to extremely useful. Utility was greatest for complex devices (89%) and new devices (88%). Advantages included insight into the team's familiarity with devices (70%) and improved teamwork and communication (68%). Users found it unrealistic to review all device instructional materials (54%). Free text responses suggested that the DBT heightened awareness of deficiencies in device familiarity and training but lacked a clear mechanism to correct them. DBT adherence was 82%. NOTECHS scores in intervention departments improved over the course of the study but did not significantly differ from comparator departments. CONCLUSIONS: The DBT was rated highly by both surgeons and nurses. Adherence was high and we found no evidence of "checklist fatigue." Centers interested in implementing the DBT should focus on devices that are complex or new to any surgical team member. Guidance for correcting deficiencies identified by the DBT will be provided in future iterations of the tool.

Causal and Associational Language in Observational Health Research: A Systematic Evaluation.

We estimated the degree to which language used in the high-profile medical/public health/epidemiology literature implied causality using language linking exposures to outcomes and action recommendations; examined disconnects between language and recommendations; identified the most common linking phrases; and estimated how strongly linking phrases imply causality. We searched for and screened 1,170 articles from 18 high-profile journals (65 per journal) published from 2010-2019. Based on written framing and systematic guidance, 3 reviewers rated the degree of causality implied in abstracts and full text for exposure/outcome linking language and action recommendations. Reviewers rated the causal implication of exposure/outcome linking language as none (no causal implication) in 13.8%, weak in 34.2%, moderate in 33.2%, and strong in 18.7% of abstracts. The implied causality of action recommendations was higher than the implied causality of linking sentences for 44.5% or commensurate for 40.3% of articles. The most common linking word in abstracts was "associate" (45.7%). Reviewers' ratings of linking word roots were highly heterogeneous; over half of reviewers rated "association" as having at least some causal implication. This research undercuts the assumption that avoiding "causal" words leads to clarity of interpretation in medical research.

Academic training of authors publishing in high-impact epidemiology and clinical journals.

BACKGROUND: To inform training program development and curricular initiatives, quantitative descriptions of the disciplinary training of research teams publishing in top-tier clinical and epidemiological journals are needed. Our objective was to assess whether interdisciplinary academic training and teamwork of authors publishing original research in 15 top-tier journals varied by year of publication (2000/2010/2020), type of journal (epidemiological/general clinical/specialty clinical), corresponding author gender, and time since the corresponding author completed formal training relative to the article publication date (<5/≥5 years). METHODS AND FINDINGS: We invited corresponding authors of original research articles to participate in an online survey (n = 103; response rate = 8.3% of 1240 invited authors). In bivariate analyses, year of publication, type of journal, gender, and recency of training were not significantly associated with interdisciplinary team composition, whether a co-author with epidemiological or biostatistical training was involved in any research stage (design/analysis/interpretation/reporting), or with participants' confidence in their own or their co-authors epidemiological or biostatistical expertise (p > 0.05 for each comparison). Exceptions were participants with more recent epidemiological training all had co-author(s) with epidemiological training contribute to study design and interpretation, and participants who published in 2020 were more likely to report being extremely confident in their epidemiological abilities. CONCLUSIONS: This study was the first to quantify interdisciplinary training among research teams publishing in epidemiological and clinical journals. Our quantitative results show research published in top-tier journals generally represents interdisciplinary teamwork and that interdisciplinary training may provide publication type options. Our qualitative results show researchers view interdisciplinary training favorably.

The role of schools in driving SARS-CoV-2 transmission: Not just an open-and-shut case.

Keeping schools open without permitting COVID-19 spread has been complicated by conflicting messages around the role of children and schools in fueling the pandemic. Here, we describe methodological limitations of research minimizing SARS-CoV-2 transmission in schools, and we review evidence for safely operating schools while reducing overall SARS-CoV-2 transmission.

On the Need to Revitalize Descriptive Epidemiology.

Nearly every introductory epidemiology course begins with a focus on person, place, and time, the key components of descriptive epidemiology. And yet in our experience, introductory epidemiology courses were the last time we spent any significant amount of training time focused on descriptive epidemiology. This gave us the impression that descriptive epidemiology does not suffer from bias and is less impactful than causal epidemiology. Descriptive epidemiology may also suffer from a lack of prestige in academia and may be more difficult to fund. We believe this does a disservice to the field and slows progress towards goals of improving population health and ensuring equity in health. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak and subsequent coronavirus disease 2019 pandemic have highlighted the importance of descriptive epidemiology in responding to serious public health crises. In this commentary, we make the case for renewed focus on the importance of descriptive epidemiology in the epidemiology curriculum using SARS-CoV-2 as a motivating example. The framework for error we use in etiological research can be applied in descriptive research to focus on both systematic and random error. We use the current pandemic to illustrate differences between causal and descriptive epidemiology and areas where descriptive epidemiology can have an important impact.

A case study and proposal for publishing directed acyclic graphs: The effectiveness of the quadrivalent human papillomavirus vaccine in perinatally HIV Infected girls.

BACKGROUND: Developing a causal graph is an important step in etiologic research planning and can be used to highlight data flaws and irreparable bias and confounding. As a case study, we consider recent findings that suggest human papillomavirus (HPV) vaccine is less effective against HPV-associated disease among girls living with HIV compared to girls without HIV. OBJECTIVES: To understand the relationship between HIV status and HPV vaccine effectiveness, it is important to outline the key assumptions of the causal mechanisms before designing a study to investigate the effect of the HPV vaccine in girls living with HIV infection. METHODS: We present a causal graph to describe our assumptions and proposed approach to explore this relationship. We hope to obtain feedback on our assumptions before data analysis and exemplify the process for designing causal graphs to inform an etiologic study. CONCLUSION: The approach we lay out in this paper may be useful for other researchers who have an interest in using causal graphs to describe and assess assumptions in their own research before undergoing data collection and/or analysis.

The Expert Next Door: Interactions With Friends and Family During the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic thrust the field of public health into the spotlight. For many epidemiologists, biostatisticians, and other public health professionals, this caused the professional aspects of our lives to collide with the personal, as friends and family reached out with concerns and questions. Learning how to navigate this space was new for many of us and required refining our communication style depending on context, setting, and audience. Some of us took to social media, utilizing our existing personal accounts to share information after sorting through and summarizing the rapidly emerging literature to keep loved ones safe. However, those in our lives sometimes asked unanswerable questions, or began distancing themselves when we suggested more stringent guidance than they had hoped for, causing additional stress during an already traumatic time. We often had to remind ourselves that we were also individuals experiencing this pandemic and that our time-intensive efforts were meaningful, relevant, and impactful. As this pandemic and other public health crises continue, we encourage members of our discipline to consider how we can best use shared lessons from this period and to recognize that our professional knowledge, when used in our personal lives, can promote, protect, and bolster confidence in public health.

Choice of Outcome in COVID-19 Studies and Implications for Policy: Mortality and Fatality.

In this brief communication, we discuss the confusion of mortality with fatality in the interpretation of evidence in the coronavirus disease 2019 (COVID-19) pandemic, and how this confusion affects the translation of science into policy and practice. We discuss how this confusion has influenced COVID-19 policy in France, Sweden, and the United Kingdom and discuss the implications for decision-making about COVID-19 vaccine distribution. We also discuss how this confusion is an example of a more general statistical fallacy we term the "Missing Link Fallacy."