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

Statin use decreases coagulation in users of vitamin K antagonists

Purpose: The purpose of the study is to determine the immediate and long-term effect of statins on coagulation in patients treated with vitamin K antagonists (VKAs). Methods: We selected patients on VKAs of two Dutch anticoagulation clinics who initiated treatment with a statin between 2009 and 2013. Patients who initiated or stopped concomitant drugs that interact with VKAs or were hospitalised during follow-up were excluded. The VKA dosage (mg/day) after statin initiation was compared with the last VKA dosage before the statin was started. Immediate and long-term differences in VKA dosage (at 6 and 12 weeks) were calculated with a paired student t test. Results: Four hund

Direct oral anticoagulant use and risk of perioperative bleeding:Evidence of absence or absence of evidence?

Clinical epidemiolog

Lipid levels and risk of venous thrombosis: results from the MEGA-study

Thrombosis and Hemostasi

Het onderzoek van ir. van Hoffen naar de Bennekomse boerensamenleving

Het enquête-materiaal, door Ir van Hoffen nagelaten, biedt aan de niet-kenner van agrarisch Bennekom de mogelijkheid enkele sociologische opmerkingen te maken over de Bennekomse boer

Afrika: hulp & handel in perspectief - lessen uit het veld

ASC – Publicaties niet-programma gebonde