Comparative effectiveness and safety of apixaban and rivaroxaban in older patients with atrial fibrillation: A population-based cohort study.

BACKGROUND: There are no clinical trials with a head-to-head comparison between the 2 most commonly used oral anticoagulants (apixaban and rivaroxaban) in patients with atrial fibrillation (AF). The comparative efficacy and safety between these drugs remain unclear, especially in older patients who are at the highest risk for stroke and bleeding. OBJECTIVE: The purpose of this study was to compare the risk of major bleeding and thromboembolic events between apixaban and rivaroxaban in older patients with AF. METHODS: We conducted a population-based retrospective cohort study of all adult patients (66 years or older) with AF in Ontario, Canada, who were treated with apixaban or rivaroxaban between April 1, 2011, and March 31, 2020. The primary safety outcome was major bleeding, and the primary efficacy outcome was thromboembolic events. Secondary outcomes included any bleeding. Rates and hazard ratios (HRs) were adjusted for baseline comorbidities with inverse probability of treatment weighting. RESULTS: This study included 42,617 patients with AF treated with apixaban and 30,725 patients treated with rivaroxaban. After inverse probability of treatment weighting using the propensity score, patients in the apixaban and rivaroxaban groups were well balanced for baseline values of demographic characteristics, comorbidities, and medications; both groups had a similar mean age of 77.4 years, and 49.9% were female. At 1 year, the apixaban group had a lower risk for both major bleeding with an absolute risk reduction at 1 year of 1.1% (2.1% vs 3.2%; HR 0.65; 95% confidence interval [CI] 0.59-0.71]) and any bleeding (8.1% vs 10.9%; HR 0.73; 95% CI 0.69-0.77), with no difference in the risk for thromboembolic events (2.2% vs 2.2%; HR 1.02; 95% CI 0.92-1.13). CONCLUSION: In patients with AF, 66 years or older, treatment with apixaban was associated with lower risk for major bleeding, with no difference in the risk for thromboembolic events compared with rivaroxaban.

A review of the use of propensity score methods with multiple treatment groups in the general internal medicine literature.

BACKGROUND: Propensity score (PS) methods with two treatment groups (e.g., treated vs. control) is a well-established technique for reducing the effects of confounding in nonrandomized studies. However, researchers are often interested in comparing multiple interventions. PS methods have been modified to incorporate multiple exposures. We described available techniques for PS methods in multicategory exposures (≥3 groups) and examined their use in the medical literature. METHODS: A comprehensive search was conducted for studies published in PubMed, Embase, Google Scholar, and Web of Science until February 27, 2023. We included studies using PS methods for multiple groups in general internal medicine research. RESULTS: The literature search yielded 4088 studies (2616 from PubMed, 86 from Embase, 85 from Google Scholar, 1671 from Web of Science, five from other sources). In total, 264 studies using PS method for multiple groups were identified; 61 studies were on general internal medicine topics and included. The most commonly used method was that of McCaffrey et al., which was used in 26 studies (43%), where the Toolkit for Weighting and Analysis of Nonequivalent Groups (TWANG) method and corresponding inverse probabilities of treatment weights were estimated via generalized boosted models. The next most commonly used method was pairwise propensity-matched comparisons, which was used in 20 studies (33%). The method by Imbens et al. using a generalized propensity score was implemented in six studies (10%). Four studies (7%) used a conditional probability of being in a particular group given a set of observed baseline covariates where a multiple propensity score was estimated using a non-parsimonious multinomial logistic regression model. Four studies (7%) used a technique that estimates generalized propensity scores and then creates 1:1:1 matched sets, and one study (2%) used the matching weight method. CONCLUSIONS: Many propensity score methods for multiple groups have been adopted in the literature. The TWANG method is the most commonly used method in the general medical literature.

Kussmaul's sign for the diagnosis of right ventricular myocardial infarction: a systematic review and meta-analysis of diagnostic test accuracy studies.

INTRODUCTION: Kussmaul's sign, the absence of a drop in jugular venous pressure or a paradoxical increase in jugular venous pressure on inspiration, can be evaluated as an indicator of right ventricular myocardial infarction. Right ventricular myocardial infarction complicates 30-50% of inferior myocardial infarctions and is associated with increased mortality when compared to inferior myocardial infarction without right ventricular involvement. Early recognition allows maintenance of preload. We reviewed the diagnostic test accuracy studies for Kussmaul's sign for diagnosis of right ventricular myocardial infarction. METHODS: We conducted a librarian-assisted search using PubMed, Medline, Embase, and the Cochrane database from 1965 to October 2019. Only English language restriction was imposed. We identified studies that assessed patients presenting to a hospital with a suspected myocardial infarction who underwent an assessment for Kussmaul's sign and a diagnostic test for right ventricular myocardial infarction. Four independent reviewers extracted data from relevant studies. Study quality was assessed using the QUADAS-2 tool. A bivariate random effects meta-analysis was performed. RESULTS: We identified 122 studies; ten were selected for full review. Eight studies had comparable populations with a total of 469 consecutive patients admitted with acute inferior myocardial infarction and were included in the analysis. Prevalence of right ventricular myocardial infarction was 36% (confidence interval [CI] 95% 31.8-40.5). All reference standards were combined. Kussmaul's sign had a sensitivity of 62.5% (44.6, 77.5), specificity 90% (73.0, 96.8), negative likelihood ratio (LR) 0.2 (0.1-0.8) and positive LR 5.8 (2.5, 13.3). CONCLUSION: In the presence of acute myocardial infarction, Kussmaul's sign is specific for acute right ventricular myocardial infarction and may serve as an important clinical sign of right ventricular dysfunction requiring preload preserving management.

RéSUMé: INTRODUCTION: Le signe de Kussmaul, l'absence de baisse de la pression veineuse jugulaire ou une augmentation paradoxale de la pression veineuse jugulaire à l'inspiration, peut être évalué comme un indicateur d'infarctus du myocarde ventriculaire droit. Elle complique 30 à 50% des infarctus du myocarde inférieur et est associée à une mortalité accrue par rapport à l'infarctus du myocarde inférieur sans atteinte ventriculaire droite. Une détection précoce permet de maintenir la précharge. Nous avons examiné les études sur la précision des tests de diagnostic du signe de Kussmaul pour le diagnostic de l'infarctus du myocarde ventriculaire droit. MéTHODES: Nous avons mené une recherche assistée par un bibliothécaire à l'aide de PubMed, Medline, Embase et la base de données Cochrane de 1965 à octobre 2019. Seule la restriction de la langue anglaise a été imposée. Nous avons identifié des études qui ont évalué des patients se présentant à un hôpital avec un infarctus suspecté de myocarde et qui ont subi une évaluation du signe de Kussmaul et un test de diagnostic pour un infarctus du myocarde ventriculaire droit. Quatre examinateurs indépendants ont extrait les données d'études pertinentes. La qualité de l'étude a été évaluée à l'aide de l'outil QUADAS-2. Une méta-analyse bivariée des effets aléatoires a été réalisée. RéSULTATS: Nous avons recensé 122 études ; dix ont été sélectionnées pour un examen complet. Huit études avaient des populations comparables avec un total de 469 patients consécutifs admis avec un infarctus aigu du myocarde inférieur et ont été inclus dans l'analyse. La prévalence de l'infarctus du myocarde ventriculaire droit était de 36 % (intervalle de confiance [IC] 95 % 31,8-40,5). Toutes les normes de référence ont été combinées. Le signe de Kussmaul avait une sensibilité de 62,5 % (44,6, 77,5), de spécificité 90 % (73,0, 96,8), un rapport de vraisemblance négatif (LR) 0,2 (0,1-0,8) et de LR positif 5,8 (2,5, 13,3). CONCLUSION: En présence d'un infarctus aigu du myocarde, le signe de Kussmaul est spécifique à l'infarctus aigu du myocarde ventriculaire droit et peut constituer un signe clinique important de dysfonctionnement du ventricule droit nécessitant une gestion de la préservation de la précharge.

Can fertigation reduce nitrous oxide emissions from wheat and canola fields?

Increasing nitrogen fertilization and irrigation can contribute to nitrous oxide (N2O) emissions from agriculture. Relative to the conventional practice of one-pass fertilization with all N applied at crop seeding, this study examined how splitting the total N fertilization into seeding time and in-crop fertigation impacts N2O emission factors (EF) in irrigated wheat (Triticum aestivum) and canola (Brassica napus) in Southern Alberta, Canada during two growing seasons (May to Oct. in 2015 and 2016). With all the N applied at crop seeding, the growing-season N2O EF of irrigated wheat and canola was in average 0.23 ± 0.03%. Conversely, implementing N fertigation lowered the magnitudes of N2O EF in each of the four crop-years, averaging 0.16 ± 0.04%. Most of the reductions in N2O emissions due to fertigation occurred with low and intermediate N rates (total rates of 60 and 90 kg N ha-1) and in the second year of the study. This second year had recurrent, early-season rainfalls following seeding (and prior to fertigation) that triggered differences in the daily and cumulative N2O fluxes. Within this year, fertigation on wheat consistently lowered the growing-season N2O EF from a high of 0.27% to only 0.11% (P < 0.001). Also, at the intermediate rate of 90 kg N ha-1, fertigation synergistically reduced the N2O EF of canola by half, from 0.13% to 0.06% (P < 0.01). However, the mitigating effects of fertigation vanished with the highest N rate in the study (120 kg N ha-1). Even with fertigation, this highest N rate resulted in high emissions in wheat, and lesser so in canola in part due to the higher N uptake of canola. Moreover, canola often manifested narrower ratios of N2O emission-to-grain yield (EFyield) than wheat. This interplay of crop species, rainfall and N management suggests that implementing fertigation with reduced N rates can proactively mitigates N2O.