Book Review 2023 A Single Step to English Communication Author & Publisher: Steven E. Quasha. Akebono Press （Steven E. Quasha. Korea: Akebono Press, 2020. pp. 174. \2,200 ISBN: 978-4-905426-70-7）

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2 kirja G. Corte`ele, Arnhemiae

http://tartu.ester.ee/record=b1886113~S1*es

COVID-19 associated coagulopathy and thromboembolic disease: commentary on an interim expert guidance

Thrombosis and Hemostasi

Predictors, time course, and outcomes of persistence patterns in oral anticoagulation for non-valvular atrial fibrillation:A Dutch Nationwide Cohort Study

Aims Persistence with direct oral anticoagulants (DOACs) has become a concern in non-valvular atrial fibrillation (NVAF) patients, but whether this affects prognosis is rarely studied. We investigated the persistence with oral anticoagulants (OACs) and its association with prognosis among a nationwide cohort of NVAF patients.Methods and results DOAC-naive NVAF patients who started to use DOACs for ischaemic stroke prevention between 2013 and 2018 were included using Dutch national statistics. Persistence with OACs was determined based on the presence of a 100-day gap between the last prescription and the end of study period. In 93 048 patients, 75.7% had a baseline CHA(2)DS(2)-VASc score of >= 2. The cumulative incidence of persistence with OACs was 88.1% [95% confidence interval (CI) 87.9-88.3%], 82.6% (95% CI 82.3-82.9%), 77.7% (95% CI 77.3-78.1%), and 72.0% (95% CI 71.5-72.5%) at 1, 2, 3, and 4 years after receiving DOACs, respectively. Baseline characteristics associated with better persistence with OACs included female sex, age range 65-74 years, permanent atrial fibrillation, previous exposure to vitamin K antagonists, stroke history (including transient ischaemic attack), and a CHA(2)DS(2)-VASc score >= 2. Non-persistence with OACs was associated with an increased risk of the composite outcome of ischaemic stroke and ischaemic stroke-related death [adjusted hazard ratio (aHR) 1.79, 95% CI 1.49-2.15] and ischaemic stroke (aHR 1.58, 95% CI 1.29-1.93) compared with being persistent with OACs.Conclusion At least a quarter of NVAF patients were non-persistent with OACs within 4 years, which was associated with poor efficacy of ischaemic stroke prevention. The identified baseline characteristics may help identify patients at risk of non-persistence.Medical Microbiolog

Suspected survivor bias in case–control studies: stratify on survival time and use a negative control

AbstractObjectivesSelection bias in case–control studies occurs when control selection is inappropriate. However, selection bias due to improper case sampling is less well recognized. We describe how to recognize survivor bias (i.e., selection on exposed cases) and illustrate this with an example study.Study Design and SettingA case–control study was used to analyze the effect of statins on major bleedings during treatment with vitamin K antagonists. A total of 110 patients who experienced such bleedings were included 18–1,018 days after the bleeding complication and matched to 220 controls.ResultsA protective association of major bleeding for exposure to statins (odds ratio [OR]: 0.56; 95% confidence interval: 0.29–1.08) was found, which did not become stronger after adjustment for confounding factors. These observations lead us to suspect survivor bias. To identify this bias, results were stratified on time between bleeding event and inclusion, and repeated for a negative control (an exposure not related to survival): blood group non-O. The ORs for exposure to statins increased gradually to 1.37 with shorter time between outcome and inclusion, whereas ORs for the negative control remained constant, confirming our hypothesis.ConclusionWe recommend the presented method to check for overoptimistic results, that is, survivor bias in case–control studies

The Absolute Risk of Venous Thrombosis after Air Travel: A Cohort Study of 8,755 Employees of International Organisations

In a cohort study of 8,755 employees of large international organizations followed for 38,910 person-years, Suzanne Cannegieter and colleagues find a risk of one thrombosis per 4,656 long-haul flights

Thrombosis after Travel

Rothman discusses a new study by Cannegieter and colleagues which looked at the interaction of lengthy travel with other risk factors for venous thromboembolism

Estimating incidence of venous thromboembolism in COVID-19:Methodological considerations

Background Coagulation abnormalities and coagulopathy are recognized as consequences of severe acute respiratory syndrome coronavirus 2 infection and the resulting coronavirus disease 2019 (COVID-19). Specifically, venous thromboembolism (VTE) has been reported as a frequent complication. By May 27, 2021, at least 93 original studies and 25 meta-analyses investigating VTE incidence in patients with COVID-19 had been published, showing large heterogeneity in reported VTE incidence ranging from 0% to 85%. This large variation complicates interpretation of individual study results as well as comparisons across studies, for example, to investigate changes in incidence over time, compare subgroups, and perform meta-analyses. Objectives This study sets out to provide an overview of sources of heterogeneity in VTE incidence studies in patients with COVID-19, illustrated using examples. Methods The original studies of three meta-analyses were screened and a list of sources of heterogeneity that may explain observed heterogeneity across studies was composed. Results The sources of heterogeneity in VTE incidence were classified as clinical sources and methodologic sources. Clinical sources of heterogeneity include differences between studies regarding patient characteristics that affect baseline VTE risk and protocols used for VTE testing. Methodologic sources of heterogeneity include differences in VTE inclusion types, data quality, and the methods used for data analysis. Conclusions To appreciate reported estimates of VTE incidence in patients with COVID-19 in relation to its etiology, prevention, and treatment, researchers should unambiguously report about possible clinical and methodological sources of heterogeneity in those estimates. This article provides suggestions for that.Thrombosis and Hemostasi