Controlled human infection (CHI) models for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proposed as a tool to accelerate the development of vaccines and drugs. Such... Show moreControlled human infection (CHI) models for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been proposed as a tool to accelerate the development of vaccines and drugs. Such models carry inherent risks. Participants may develop severe disease or complications after deliberate infection. Prolonged isolation may negatively impact their well-being. Through secondary infection of study personnel or participant household contacts, the experimental virus strain may cause a community outbreak. We identified risks associated with such a SARS-CoV-2 CHI model and assessed their likelihood and impact and propose strategies that mitigate these risks. In this report, we show that risks can be minimized with proper risk mitigation strategies; the residual risk, however, should be weighed carefully against the scientific and social values of such a CHI model. Show less
Background The Coronavirus disease 2019 (COVID-19) pandemic has underlined the urgent need for reliable, multicenter, and full-admission intensive care data to advance our understanding of the... Show moreBackground The Coronavirus disease 2019 (COVID-19) pandemic has underlined the urgent need for reliable, multicenter, and full-admission intensive care data to advance our understanding of the course of the disease and investigate potential treatment strategies. In this study, we present the Dutch Data Warehouse (DDW), the first multicenter electronic health record (EHR) database with full-admission data from critically ill COVID-19 patients. Methods A nation-wide data sharing collaboration was launched at the beginning of the pandemic in March 2020. All hospitals in the Netherlands were asked to participate and share pseudonymized EHR data from adult critically ill COVID-19 patients. Data included patient demographics, clinical observations, administered medication, laboratory determinations, and data from vital sign monitors and life support devices. Data sharing agreements were signed with participating hospitals before any data transfers took place. Data were extracted from the local EHRs with prespecified queries and combined into a staging dataset through an extract-transform-load (ETL) pipeline. In the consecutive processing pipeline, data were mapped to a common concept vocabulary and enriched with derived concepts. Data validation was a continuous process throughout the project. All participating hospitals have access to the DDW. Within legal and ethical boundaries, data are available to clinicians and researchers. Results Out of the 81 intensive care units in the Netherlands, 66 participated in the collaboration, 47 have signed the data sharing agreement, and 35 have shared their data. Data from 25 hospitals have passed through the ETL and processing pipeline. Currently, 3464 patients are included in the DDW, both from wave 1 and wave 2 in the Netherlands. More than 200 million clinical data points are available. Overall ICU mortality was 24.4%. Respiratory and hemodynamic parameters were most frequently measured throughout a patient's stay. For each patient, all administered medication and their daily fluid balance were available. Missing data are reported for each descriptive. Conclusions In this study, we show that EHR data from critically ill COVID-19 patients may be lawfully collected and can be combined into a data warehouse. These initiatives are indispensable to advance medical data science in the field of intensive care medicine. Show less
This article explores how competing actors established, spread, and challenged visual representations of the Chinese nation during the COVID-19 pandemic. It asks: how do official gatekeepers of... Show moreThis article explores how competing actors established, spread, and challenged visual representations of the Chinese nation during the COVID-19 pandemic. It asks: how do official gatekeepers of meaning in China imbue their visual construction of a crisis-hit nation with pathos?; and what happens when their critics utilize the resulting repertoire of visual cues for their own ends? To answer these questions, the article first examines the visual libraries of nationalism and national crisis from which Chinese propaganda drew during the COVID-19 outbreak. It then analyses the struggles that ensued over such representations, specifically the use of national flags and the sentiments they elicit. The analysis traces representations of the flag of the People’s Republic of China (PRC) from an initial satirical portrayal in a Danish broadsheet to the angry Chinese backlashes that followed on social media, and it shows how the tensions over such portrayals became part of a meme war over the sovereignty of Hong Kong. The analysis shows how representations of the nation can become a matter of existential anxieties during a time of crisis, especially in highly networked communication environments where authoritative official actors and their supporters are no longer in control of the symbols they established as part of their ‘emotional governance’. Show less
Derksen, V.F.A.M.; Kissel, T.; Lamers-Karnebeek, F.B.G.; Bijl, A.E. van der; Venhuizen, A.C.; Huizinga, T.W.J.; ... ; Woude, D. van der 2021
In this review, we discuss spatiotemporal kinetics and inflammatory signatures of innate immune cells specifically found in response to SARS-CoV-2 compared to influenza virus infection. Importantly... Show moreIn this review, we discuss spatiotemporal kinetics and inflammatory signatures of innate immune cells specifically found in response to SARS-CoV-2 compared to influenza virus infection. Importantly, we cover the current understanding on the mechanisms by which SARS-CoV-2 may fail to engage a coordinated type I response and instead may lead to exaggerated inflammation and death. This knowledge is central for the understanding of available data on specialized pro-resolving lipid mediators in severe SARS-CoV-2 infection pointing toward inhibited E-series resolvin synthesis in severe cases. By investigating a publicly available RNA-seq database of bronchoalveolar lavage cells from patients affected by COVID-19, we moreover offer insights into the regulation of key enzymes involved in lipid mediator synthesis, critically complementing the current knowledge about the mediator lipidome in severely affected patients. This review finally discusses different potential approaches to sustain the synthesis of 3-PUFA-derived pro-resolving lipid mediators, including resolvins and lipoxins, which may critically aid in the prevention of acute lung injury and death from COVID-19. Show less
The relationship between COVID-19 and diabetes mellitus is complicated and bidirectional. On the one hand, diabetes mellitus is considered one of the most important risk factors for a severe course... Show moreThe relationship between COVID-19 and diabetes mellitus is complicated and bidirectional. On the one hand, diabetes mellitus is considered one of the most important risk factors for a severe course of COVID-19. Several factors that are often present in diabetes mellitus are likely to contribute to this risk, such as older age, a proinflammatory and hypercoagulable state, hyperglycemia and underlying comorbidities (hypertension, cardiovascular disease, chronic kidney disease and obesity). On the other hand, a severe COVID-19 infection, and its treatment with steroids, can have a specific negative impact on diabetes itself, leading to worsening of hyperglycemia through increased insulin resistance and reduced beta-cell secretory function. Worsening hyperglycemia can, in turn, adversely affect the course of COVID-19. Although more knowledge gradually surfaces as the pandemic progresses, challenges in understanding the interrelationship between COVID-19 and diabetes remain. Show less
Accumulating studies on COVID-19 patients report high incidences of thrombotic complications, but guidance on the best diagnostic approach for suspected pulmonary embolism (PE) in COVID-19 patients... Show moreAccumulating studies on COVID-19 patients report high incidences of thrombotic complications, but guidance on the best diagnostic approach for suspected pulmonary embolism (PE) in COVID-19 patients is lacking. Diagnosing PE in these patients is challenging as signs and symptoms of PE and COVID-19 show wide overlap, D-dimer levels are often elevated in the absence of thrombosis and computed tomography pulmonary angiography (CTPA) may be unfeasible in the case of severe renal impairment and/or hemodynamic instability. This narrative review discusses available literature and guidelines on current diagnostic algorithms for suspected PE in special patient populations, in particular COVID-19. A special focus is on reviewing the literature aimed at identifying symptoms with a high suspicion for PE and on the diagnostic performance of diagnostic algorithms for suspected PE in the setting of COVID-19. Based on available literature, the index of suspicion for PE should be high in the case of unexplained abrupt worsening of respiratory status, typical symptoms of deep-vein thrombosis and/or acute unexplained right ventricular dysfunction. Despite the lack of prospective diagnostic management studies, we propose to adhere to current diagnostic algorithms applying assessment of pretest probability and D-dimer testing as available evidence suggests that these might be considered safe. Preferably, algorithms using adjusted D-dimer thresholds are recommended as it likely improves the yield of the clinical decision rule/D-dimer combination. Show less
Background: We systematically reviewed the literature to answer the following research questions: (1) Does interleukin 6 (IL-6) (receptor) antagonist therapy reduce mortality in coronavirus disease... Show moreBackground: We systematically reviewed the literature to answer the following research questions: (1) Does interleukin 6 (IL-6) (receptor) antagonist therapy reduce mortality in coronavirus disease 2019 (COVID-19) patients compared to patients not treated with IL-6 (receptor) antagonists; and (2) is there an increased risk of side effects in COVID-19 patients treated with IL-6 (receptor) antagonists compared to patients not treated with IL-6 (receptor) antagonists?Methods: We systematically searched PubMed, PMC PubMed Central, Medline, World Health Organization COVID-19 Database, Embase, Web of Science, Cochrane Library, Emcare, and Academic Search Premier (through 30 June 2020). Random effects meta-analysis was used to pool the risk ratios and risk differences of individual studies. Risk of bias was appraised using the Methodological Index for Non-randomized Studies (MINORS) checklist.Results: The search strategy retrieved 743 unique titles, of which 10 studies (all on tocilizumab [TCZ]) comprising 1358 patients were included. Nine of 10 studies were considered to be of high quality. Meta-analysis showed that the TCZ group had lower mortality than the control group. The risk ratio was 0.27 (95% confidence interval [CI], .12-.59) and the risk difference was 12% (95% CI, 4.6%-20%) in favor of the TCZ group. With only a few studies available, there were no differences observed regarding side effects.Conclusions: Our results showed that mortality was 12% lower for COVID-19 patients treated with TCZ compared with those not treated with TCZ. The number needed to treat was 11, suggesting that for every 11 (severe) COVID-19 patients treated with TCZ, 1 death is prevented. These results require confirmation by randomized controlled trials. Show less
Objectives Overcrowding in acute care services gives rise to major problems, such as reduced accessibility and delay in treatment. In order to be able to continue providing high-quality health care... Show moreObjectives Overcrowding in acute care services gives rise to major problems, such as reduced accessibility and delay in treatment. In order to be able to continue providing high-quality health care, it is important that organizations are well integrated at all organizational levels. The objective of this study was to to gain an understanding in which extent cooperation within an urban acute care network in the Netherlands (The Hague) improved because of the COVID-19 crisis. Methods Exploratory mixed-methods questionnaire and qualitative interview study. Semistructured interviews with stakeholders in the acute care network at micro (n = 10), meso (n = 9), and macro (n = 3) levels of organization. Thematic analysis took place along the lines of the 6 dimensions of the Rainbow Model of Integrated Care. Results In this study we identified themes that may act as barriers or facilitators to cooperation: communication, interaction, trust, leadership, interests, distribution of care, and funding. During the crisis many facilitators were identified at clinical, professional, and system level such as clear agreements about work processes, trust in each other's work, and different stakeholders growing closer together. However, at an organizational and communicative level there were many barriers such as interference in each other's work and a lack of clear policies. Conclusion The driving force behind all changes in integration of acute care organizations in an urban context during the COVID-19 crisis seemed to be a great sense of urgency to cooperate in the shared interest of providing the best patient care. We recommend shifting the postcrisis focus from overcoming the crisis to overcoming cooperative challenges. Show less
Aims To investigate changes in physical activity (PA) and psychological factors during societal lockdown in people with type 2 diabetes.Methods A cross-sectional study among Dutch adults with type... Show moreAims To investigate changes in physical activity (PA) and psychological factors during societal lockdown in people with type 2 diabetes.Methods A cross-sectional study among Dutch adults with type 2 diabetes. Data were collected using online questionnaires. A multivariate multinomial logistic regression was performed with change in PA during societal lockdown as outcome and perceived change in stress, anxiety, perceived risk for COVID-19 infection, emotional well-being and former PA status as determinants.Results Five hundred and sixty seven respondents filled out the questionnaire, 536 were included in the final analysis: mean age of 65.9 +/- 7.9 years; mean diabetes duration 13.3 +/- 8 years; 54% men; 47% reported no change in PA, 27% became less active and 26% became more active during societal lockdown. Participants who were more likely to become less active were participants who experienced more stress (OR: 2.27; 95% CI 1.25-4.13) or less stress (OR: 2.20; 95% CI 1.03-4.71). Participants who were more likely to become more active were participants who experienced more stress (OR: 2.31; 95% CI 1.25, 4.26). Participants with higher emotional well-being (OR: 0.98; 95% CI 0.97, 0.99) were less likely to become less active than to report no change in PA.Conclusions Changes in PA in people with type 2 diabetes during societal lockdown are associated with changes in psychological factors such as perceived stress and emotional well-being. People with diabetes and their caregivers should be aware of these possible changes. Show less
Gravesteijn, B.; Krijkamp, E.; Busschbach, J.; Geleijnse, G.; Helmrich, I.R.; Bruinsma, S.; ... ; Value Based Operation Room Triage 2021
Objectives: Coronavirus disease 2019 has put unprecedented pressure on healthcare systems worldwide, leading to a reduction of the available healthcare capacity. Our objective was to develop a... Show moreObjectives: Coronavirus disease 2019 has put unprecedented pressure on healthcare systems worldwide, leading to a reduction of the available healthcare capacity. Our objective was to develop a decision model to estimate the impact of postponing semielective surgical procedures on health, to support prioritization of care from a utilitarian perspective. Methods: A cohort state-transition model was developed and applied to 43 semielective nonpediatric surgical procedures commonly performed in academic hospitals. Scenarios of delaying surgery from 2 weeks were compared with delaying up to 1 year and no surgery at all. Model parameters were based on registries, scientific literature, and the World Health Organization Global Burden of Disease study. For each surgical procedure, the model estimated the average expected disability-adjusted life-years (DALYs) per month of delay. Results: Given the best available evidence, the 2 surgical procedures associated with most DALYs owing to delay were bypass surgery for Fontaine III/IV peripheral arterial disease (0.23 DALY/month, 95% confidence interval [CI]: 0.13-0.36) and trans aortic valve implantation (0.15 DALY/month, 95% CI: 0.09-0.24). The 2 surgical procedures with the least DALYs were placing a shunt for dialysis (0.01, 95% CI: 0.005-0.01) and thyroid carcinoma resection (0.01, 95% CI: 0.01-0.02). Conclusion: Expected health loss owing to surgical delay can be objectively calculated with our decision model based on best available evidence, which can guide prioritization of surgical procedures to minimize population health loss in times of scarcity. The model results should be placed in the context of different ethical perspectives and combined with capacity management tools to facilitate large-scale implementation. Show less
Rogier, C.; Dijk, B.T. van; Brouwer, E.; Jong, P.H.P. de; Helm-van Mil, A.H.M. van der 2021
Older multi-morbid persons often fall seriously ill due to COVID-19. To be able to participate in a social life again, they often need special rehabilitation measures. Geriatric rehabilitation is a... Show moreOlder multi-morbid persons often fall seriously ill due to COVID-19. To be able to participate in a social life again, they often need special rehabilitation measures. Geriatric rehabilitation is a multi-professional service geared to these needs. Paradoxically, however, capacities in geriatric rehabilitation are currently being reduced despite increasing demand. The reasons are manifold and are not only due to the current situation. This article highlights the current situation leading to the COVID rehabilitation paradox and shows ways to learn from it for the future. Show less
Background In patients hospitalised with COVID-19, an increased incidence of thromboembolic events, such as pulmonary embolism, deep vein thrombosis and stroke, has been reported. It is unknown... Show moreBackground In patients hospitalised with COVID-19, an increased incidence of thromboembolic events, such as pulmonary embolism, deep vein thrombosis and stroke, has been reported. It is unknown whether anticoagulation can prevent these complications and improve outcome. Methods A systematic literature search was performed to answer the question: What is the effect of (prophylactic and therapeutic dose) anticoagulation therapy in COVID-19 patients on cardiovascular and thromboembolic complications and clinical outcome? Relevant outcome measures were mortality (crucial), hospital admission, length of stay, thromboembolic complications (pulmonary embolism, stroke, transient ischaemic attack), need for mechanical ventilation, acute kidney injury and use of renal replacement therapy. Medline and Embase databases were searched with relevant search terms until 17 July 2020. After systematic analysis, eight studies were included. Analysis was stratified for the start of anticoagulation before or during hospital admission. Results There was insufficient evidence that therapeutic anticoagulation could improve the outcome in patients hospitalised with COVID-19. None of the studies demonstrated improved mortality, except for one very small Italian study. Furthermore, none of the studies showed a positive effect of anticoagulation on other outcome measures in COVID-19, such as ICU admission, length of hospital stay, thromboembolic complications, need for mechanical ventilation, acute kidney failure or need for renal replacement therapy, except for two studies demonstrating an association between anticoagulation and a lower incidence of pulmonary embolism. However, the level of evidence of all studies varied from 'low' to 'very low', according to the GRADE methodology. Conclusion Analysis of the literature showed that there was insufficient evidence to answer our objective on the effect of anticoagulation on outcome in COVID-19 patients, especially due to the low scientific quality of the described studies. Randomised controlled studies are needed to answer this question. Show less
Background Hospitalised COVID-19 patients with underlying cardiovascular disease (CVD) and cardiovascular risk factors appear to be at risk of poor outcome. It is unknown if these patients should... Show moreBackground Hospitalised COVID-19 patients with underlying cardiovascular disease (CVD) and cardiovascular risk factors appear to be at risk of poor outcome. It is unknown if these patients should be considered a vulnerable group in healthcare delivery and healthcare recommendations during the COVID-19 pandemic. Methods A systematic literature search was performed to answer the following question: In which hospitalised patients with proven COVID-19 and with underlying CVD and cardiovascular risk factors should doctors be alert to a poor outcome? Relevant outcome measures were mortality and intensive care unit admission. Medline and Embase databases were searched using relevant search terms until 9 June 2020. After systematic analysis, 8 studies were included. Results Based on the literature search, there was insufficient evidence that CVD and cardiovascular risk factors are significant predictors of mortality and poor outcome in hospitalised patients with COVID-19. Due to differences in methodology, the level of evidence of all studies was graded 'very low' according to the Grading Recommendations Assessment, Development and Evaluation methodology. It is expected that in the near future, two multinational and multicentre European registries (CAPACITY-COVID and LEOSS) will offer more insight into outcome in COVID-19 patients. Conclusion This literature review demonstrated there was insufficient evidence to identify CVD and cardiovascular risk factors as important predictors of poor outcome in hospitalised COVID-19 patients. However, patients with CVD and cardiovascular risk factors remain vulnerable to infectious disease outbreaks. As such, governmental and public health COVID-19 recommendations for vulnerable groups apply to these patients. Show less
Background There has been debate on the use of angiotensin-converting enzyme-2 (ACE2) expression mediating pharmacotherapy in COVID-19 infected patients. Although it has been suggested that these... Show moreBackground There has been debate on the use of angiotensin-converting enzyme-2 (ACE2) expression mediating pharmacotherapy in COVID-19 infected patients. Although it has been suggested that these drugs might lead to a higher susceptibility and severity of COVID-19 infection, experimental data suggest these agents may reduce acute lung injury via blocking angiotensin-II-mediated pulmonary permeability, inflammation and fibrosis. Methods A systematic literature search was performed to answer the question: What is the effect of medications that influence ACE2 expression (ACE inhibitors (ACEIs), angiotensin receptor blockers (ARBs), nonsteroidal anti-inflammatory drugs (NSAIDs) and thiazolidinediones) on the outcomes of COVID-19? Relevant outcome measures were mortality (crucial), hospital admission, length of stay, thromboembolic complications (pulmonary embolism, stroke, transient ischaemic attack), need for mechanical ventilation, acute kidney injury and use of renal replacement therapy. Medline and Embase databases were searched with relevant search terms until 24 June 2020. After systematic analysis, nine studies were included. Results The results were described for two different groups, an overall group in which all users were compared with non-users and a group in which only hypertensive patients were included. Within each group a distinction was made between results for ACEI/ARB use, ACEI use, ARB use, NSAID use and thiazolidinedione use. None of the studies demonstrated increased mortality in the two groups. Furthermore, none of the studies showed an effect on other outcome measures in COVID-19, such as ICU admission, length of hospital stay, thromboembolic complications, need for mechanical ventilation, acute kidney failure or need for renal replacement therapy. However, the level of evidence of all studies varied from 'moderate' to 'very low', according to the GRADE methodology. Conclusion Analysis of the literature demonstrated that there was insufficient evidence to answer our objective on the effect of ACE2 expression mediating pharmacotherapy on outcome in COVID-19 patients, especially due to the low scientific quality of the described studies. Randomised controlled studies are needed to answer this question. Show less
Background COVID-19 can cause myocardial injury in a significant proportion of patients admitted to the hospital and seems to be associated with worse prognosis. The aim of this review was to study... Show moreBackground COVID-19 can cause myocardial injury in a significant proportion of patients admitted to the hospital and seems to be associated with worse prognosis. The aim of this review was to study how often and to what extent COVID-19 causes myocardial injury and whether this is an important contributor to outcome with implications for management. Methods A literature search was performed in Medline and Embase. Myocardial injury was defined as elevated cardiac troponin (cTn) levels with at least one value > 99th percentile of the upper reference limit. The primary outcome measure was mortality, whereas secondary outcome measures were intensive care unit (ICU) admission and length of hospital stay. Results Four studies and one review were included. The presence of myocardial injury varied between 9.6 and 46.3%. Myocardial injury was associated with a higher mortality rate (risk ratio (RR) 5.54, 95% confidence interval (CI) 3.48-8.80) and more ICU admissions (RR 3.78, 95% CI 2.07-6.89). The results regarding length of hospital stay were inconclusive. Conclusion Patients with myocardial injury might be classified as high-risk patients, with probably a higher mortality rate and a larger need for ICU admission. cTn levels can be used in risk stratification models and can indicate which patients potentially benefit from early medication administration. We recommend measuring cTn levels in all COVID-19 patients admitted to the hospital or who deteriorate during admission. Show less
Background: Whereas accumulating studies on patients with coronavirus disease 2019 (COVID-19) report high incidences of thrombotic complications, large studies on clinically relevant thrombosis in... Show moreBackground: Whereas accumulating studies on patients with coronavirus disease 2019 (COVID-19) report high incidences of thrombotic complications, large studies on clinically relevant thrombosis in patients with other respiratory tract infections are lacking. How this high risk in COVID-19 patients compares to those observed in hospitalized patients with other viral pneumonias such as influenza is unknown.Objectives: To assess the incidence of venous and arterial thrombotic complications in hospitalized patients with influenza as opposed to that observed in hospitalized patients with COVID-19.Methods: This was a retrospective cohort study; we used data from Statistics Netherlands (study period: 2018) on thrombotic complications in hospitalized patients with influenza. In parallel, we assessed the cumulative incidence of thrombotic complications-adjusted for competing risk of death-in patients with COVID-19 in three Dutch hospitals (February 24 to April 26, 2020).Results: Of the 13 217 hospitalized patients with influenza, 437 (3.3%) were diagnosed with thrombotic complications, versus 66 (11%) of the 579 hospitalized patients with COVID-19. The 30-day cumulative incidence of any thrombotic complication in influenza was 11% (95% confidence interval [CI], 9.4-12) versus 25% (95% CI, 18-32) in COVID-19. For venous thrombotic (VTC) complications and arterial thrombotic complications alone, these numbers were, respectively, 3.6% (95% CI, 2.7-4.6) and 7.5% (95% CI, 6.3-8.8) in influenza versus 23% (95% CI, 16-29) and 4.4% (95% CI, 1.9-8.8) in COVID-19.Conclusions: The incidence of thrombotic complications in hospitalized patients with influenza was lower than in hospitalized patients with COVID-19. This difference was mainly driven by a high risk of VTC complications in the patients with COVID-19 admitted to the Intensive Care Unit. Remarkably, patients with influenza were more often diagnosed with arterial thrombotic complications. Show less
Currently, the impacts of Covid-19 are receiving significant global attention. This also applies to the extractive industries, where this global crisis is directing the gaze of policymakers, donors... Show moreCurrently, the impacts of Covid-19 are receiving significant global attention. This also applies to the extractive industries, where this global crisis is directing the gaze of policymakers, donors and academics alike. Covid-19 is seen as having far-reaching and disruptive consequences, especially in the case of artisanal and small-scale mining. While the authors consider this attention important, their work on artisanal and small-scale mining in Ghana – and West Africa more broadly – reveals that for many miners, Covid-19 is ‘just’ another interruption to their lives and lifeworlds which are chronically affected by interruptions of different scales, magnitudes and temporalities. As anthropologists have shown, foregrounding this structural condition – which is emblematic for the lives of many people, especially in the Global South – is key to questioning, understanding and contextualizing the current moment of ‘global’ crisis and must be an element of any policy and research emerging from it. Show less
Background: SARS-CoV-2 is straining health care systems globally. The burden on hospitals during the pandemic could be reduced by implementing prediction models that can discriminate patients who... Show moreBackground: SARS-CoV-2 is straining health care systems globally. The burden on hospitals during the pandemic could be reduced by implementing prediction models that can discriminate patients who require hospitalization from those who do not. The COVID-19 vulnerability (C-19) index, a model that predicts which patients will be admitted to hospital for treatment of pneumonia or pneumonia proxies, has been developed and proposed as a valuable tool for decision-making during the pandemic. However, the model is at high risk of bias according to the "prediction model risk of bias assessment" criteria, and it has not been externally validated.Objective: The aim of this study was to externally validate the C-19 index across a range of health care settings to determine how well it broadly predicts hospitalization due to pneumonia in COVID-19 cases.Methods: We followed the Observational Health Data Sciences and Informatics (OHDSI) framework for external validation to assess the reliability of the C-19 index. We evaluated the model on two different target populations, 41,381 patients who presented with SARS-CoV-2 at an outpatient or emergency department visit and 9,429,285 patients who presented with influenza or related symptoms during an outpatient or emergency department visit, to predict their risk of hospitalization with pneumonia during the following 0-30 days. In total, we validated the model across a network of 14 databases spanning the United States, Europe, Australia, and Asia.Results: The internal validation performance of the C-19 index had a C statistic of 0.73, and the calibration was not reported by the authors. When we externally validated it by transporting it to SARS-CoV-2 data, the model obtained C statistics of 0.36, 0.53 (0.473-0.584) and 0.56 (0.488-0.636) on Spanish, US, and South Korean data sets, respectively. The calibration was poor, with the model underestimating risk. When validated on 12 data sets containing influenza patients across the OHDSI network, the C statistics ranged between 0.40 and 0.68.Conclusions: Our results show that the discriminative performance of the C-19 index model is low for influenza cohorts and even worse among patients with COVID-19 in the United States, Spain, and South Korea. These results suggest that C-19 should not be used to aid decision-making during the COVID-19 pandemic. Our findings highlight the importance of performing external validation across a range of settings, especially when a prediction model is being extrapolated to a different population. In the field of prediction, extensive validation is required to create appropriate trust in a model. Show less
