The win ratio method: a novel hierarchical endpoint for pneumonia trials in patients on mechanical ventilation
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SUBMITTER: Montgomery A
PROVIDER: S-EPMC4069592 | biostudies-literature | 2014 Jan
REPOSITORIES: biostudies-literature
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Project description:AimsMultiple endpoints with varying clinical relevance are available to establish the efficacy of device-based treatments. Given the variance among blood pressure measures and medication changes in hypertension trials, we performed a win ratio analysis of outcomes in a sham-controlled, randomised trial of renal denervation (RDN) in patients with uncontrolled hypertension despite commonly prescribed antihypertensive medications. We propose a novel prioritised endpoint framework for determining the treatment benefit of RDN compared with sham control.Methods and resultsWe analysed the SPYRAL HTN-ON MED pilot study data using a prioritised hierarchical endpoint comprised of 24-hour mean ambulatory systolic blood pressure (SBP), office SBP, and medication burden. A generalised pairwise comparisons methodology (win ratio) was extended to examine this endpoint. Clinically relevant thresholds of 5 and 10 mmHg were used for comparisons of ambulatory and office SBP, respectively, and therefore to define treatment "winners" and "losers". For a total number of 1,596 unmatched pairs, the RDN subject was the winner in 1,050 pairs, the RDN subject was the loser in 378 pairs, and 168 pairs were tied. The win ratio in favour of RDN was 2.78 (95% confidence interval [CI]: 1.58 to 5.48; p<0.001) and corresponding net benefit statistic was 0.42 (95% CI: 0.20 to 0.63). Sensitivity analyses performed with differing blood pressure thresholds and according to drug adherence testing demonstrated consistent results.ConclusionsThe win ratio method addresses prior limitations by enabling inclusion of more patient-oriented results while prioritising those endpoints considered most clinically important. Applying these methods to the SPYRAL HTN-ON MED pilot study (ClinicalTrials.gov Identifier: NCT02439775), RDN was determined to be superior regarding a hierarchical endpoint and a "winner" compared with sham control patients.
| S-EPMC9724872 | biostudies-literature
Project description:Required mechanical ventilation (MV) may contribute to bacterial dissemination in patients with Streptococcus pneumoniae pneumonia. Significant variations in plasma mitochondrial DNA (mtDNA) have been reported in sepsis according to the outcome. The impact of lung stretch during MV was addressed in a model of pneumonia. Healthy or S. pneumoniae infected rabbits were submitted to MV or kept spontaneously breathing (SB). Bacterial burden, cytokines release, mitochondrial DNA levels, integrity and transcription were assessed along with 48-hour mortality. Compared with infected SB rabbits, MV rabbits developed more severe pneumonia with greater concentrations of bacteria in the lungs, higher rates of systemic dissemination, higher levels of circulating inflammatory mediators and decreased survival. Pulmonary mtDNA levels were significantly lower in infected animals as compared to non-infected ones, whenever they were SB or MV. After a significant early drop, circulating mtDNA levels returned to baseline values in the infected SB rabbits, but remained low until death in the MV ones. Whole blood ex-vivo stimulation with Streptococcus pneumoniae resulted in a reduction of polymorphonuclear leukocytes mitochondrial density and plasma mtDNA concentrations. Thus, persistent mitochondrial depletion and dysfunction in the infected animals submitted to MV could account for their less efficient immune response against S. pneumoniae.
| S-EPMC6078986 | biostudies-literature
Project description:BackgroundThe emergence of multi-drug resistant pathogens is an urgent health-related problem, and the appropriate use of antibiotics is imperative. It is often difficult to identify the causative bacteria in patients with aspiration pneumonia because tracheal aspirate contains contaminants of oral bacteria. We investigated the dynamics of microbiota in mechanically ventilated patients with aspiration pneumonia to develop a treatment strategy.MethodsTwenty-two intubated patients with aspiration pneumonia were recruited. Saliva and tracheal aspirate of the subjects were collected at three time points: (A) within 2 h after intubation, (B) just before administration of antibiotics, and (C) 48-72 h after administration of antibiotics. The microbiota in each specimen was analyzed by using the 16S rRNA gene clone library sequencing method. Bacterial floras of the samples were analyzed by principal component analysis.ResultsPrincipal component analysis based on the composition of genus revealed that although the changes of microbiota in the saliva from (A) to (B) were not clear, the composition of anaerobes in the tracheal aspirate (B) was lower than (A). In fact, the reduction of anaerobes, not in the saliva but in the tracheal aspirate from (A) to (B), was confirmed by incident rate ratios estimated by a multilevel Poisson regression model (p < 0.001). The extent of decrease in anaerobes was fully dependent on the time difference between the sampling of tracheal aspirate (A) and (B)-in particular, over 3 h of mechanical ventilation. This indicates that the alterations of microbiota (involving the reduction of anaerobes in the lower respiratory tract) occurred during mechanical ventilation prior to the administration of antibiotics. After the administration of antibiotics, Enterobacter spp., Corynebacterium spp., Pseudomonas aeruginosa, Klebsiella pneumoniae, Staphylococcus aureus, and Granulicatera adiacens were predominantly detected in the tracheal aspirate (C).ConclusionThe microbiota of the lower respiratory tract changes dynamically during mechanical ventilation and during the administration of antibiotics in intubated patients with aspiration pneumonia. Antibiotics should be selected on the premise that dynamic changes in microbiota (involved in the reduction of anaerobes) may occur during the mechanical ventilation in these patients.
| S-EPMC6929358 | biostudies-literature
Project description:Home mechanical ventilation (HMV) is an increasingly common intervention and is initiated for a range of pathological processes, including neuromuscular disease (NMD), chronic obstructive pulmonary disease (COPD) and obesity related respiratory failure. There have been important recent data published in this area, which helps to guide practice by indicating which populations may benefit from this intervention and the optimum method of setting up and controlling sleep disordered breathing. Recent superficially conflicting data has been published regarding HMV in COPD, with a trial in post-exacerbation patients suggesting no benefit, but in stable chronic hypercapnic patients suggesting a clear and sustained mortality benefit. The two studies are critiqued and the potential reasons for the differing results are discussed. Early and small trial data is frequently contradicted with larger randomised controlled trials and this has been the case with diaphragm pacing being shown to be potentially harmful in the latest data, confirming the importance of non-invasive ventilation (NIV) in NMD such as motor neurone disease. Advances in ventilator technology have so far appeared quicker than the clinical data to support their use; although small and often unblinded, the current data suggests equivalence to standard modes of NIV, but with potential comfort benefits that may enhance adherence. The indications for NIV have expanded since its inception, with an effort to treat sleep disordered breathing as a result of chronic heart failure (HF). The SERVE-HF trial has recently demonstrated no clear advantage to this technology and furthermore detected a potentially deleterious effect, with a worsening of all cause and cardiovascular mortality in the treated group compared to controls. The review serves to provide the reader with a critical review of recent advances in the field of sleep disordered breathing and HMV.
| S-EPMC4739968 | biostudies-literature
Project description:The win ratio method for analysing a composite clinical hierarchy of outcomes is growing in popularity especially in cardiovascular trials. This article gives a perspective on its use so far and the issues derived from that experience. Specifically, it focuses on the limitations of a conventional composite outcome; how does the win ratio work, what does it mean, and how to display its findings; guidance on choosing an appropriate clinical hierarchy of outcomes including clinical events, quantitative outcomes, and other options; the additional value of the win difference as a measure of absolute benefit: extension to stratified win ratio, subgroup analysis, matched win ratio, and covariate adjustment; determining trial size for a win ratio outcome; specific insights such as adaptive designs, use of repeat events, and use of margins and time averages for quantitative outcomes; a critique of potential misuses; availability of statistical software; and a statistical appendix on the methodological details. Throughout, each principle is illustrated by examples from specific cardiology trials. The article concludes with a set of recommendations for future use of the win ratio.
| S-EPMC11578645 | biostudies-literature
Project description:The win ratio approach proposed by Pocock et al. (2012) has become a popular tool for analyzing composite endpoints of death and non-fatal events like hospitalization. Its standard version, however, draws on the non-fatal event only through the first occurrence. For statistical efficiency and clinical interpretability, we construct and compare different win ratio variants that make fuller use of recurrent events. We pay special attention to a variant called last-event-assisted win ratio, which compares two patients on the cumulative frequency of the non-fatal event, with ties broken by the time of its latest episode. It is shown that last-event-assisted win ratio uses more data than the standard win ratio does but reduces to the latter when the non-fatal event occurs at most once. We further prove that last-event-assisted win ratio rejects the null hypothesis with large probability if the treatment stochastically delays all events. Simulations under realistic settings show that the last-event-assisted win ratio test consistently enjoys higher power than the standard win ratio and other competitors. Analysis of a real cardiovascular trial provides further evidence for the practical advantages of the last-event-assisted win ratio. Finally, we discuss future work to develop meaningful effect size estimands based on the extended rules of comparison. The R-code for the proposed methods is included in the package WR openly available on the Comprehensive R Archive Network.
| S-EPMC9246892 | biostudies-literature
Project description:Ventilator-associated pneumonia (VAP) is common during mechanical ventilation (MV). Beside obvious deleterious effects on muco-ciliary clearance, MV could adversely shift the host immune response towards a pro-inflammatory pattern through toll-like receptor (TLRs) up-regulation. We tested this hypothesis in a rabbit model of Staphylococcus aureus VAP. Pneumonia was caused by airway challenge with S. aureus, in either spontaneously breathing (SB) or MV rabbits (n = 13 and 17, respectively). Pneumonia assessment regarding pulmonary and systemic bacterial burden, as well as inflammatory response was done 8 and 24 hours after S. aureus challenge. In addition, ex vivo stimulations of whole blood taken from SB or MV rabbits (n = 7 and 5, respectively) with TLR2 agonist or heat-killed S. aureus were performed. Data were expressed as mean±standard deviation. After 8 hours of infection, lung injury was more severe in MV animals (1.40±0.33 versus [vs] 2.40±0.55, p = 0.007), along with greater bacterial concentrations (6.13±0.63 vs. 4.96±1.31 colony forming units/gram, p = 0.002). Interleukin (IL)-8 and tumor necrosis factor (TNF)-αserum concentrations reached higher levels in MV animals (p = 0.010). Whole blood obtained from MV animals released larger amounts of cytokines if stimulated with TLR2 agonist or heat-killed S. aureus (e.g., TNF-α: 1656±166 vs. 1005±89; p = 0.014). Moreover, MV induced TLR2 overexpression in both lung and spleen tissue. MV hastened tissue injury, impaired lung bacterial clearance, and promoted a systemic inflammatory response, maybe through TLR2 overexpression.
| S-EPMC4938582 | biostudies-literature
Project description:This study aimed to investigate whether n-3 fatty acid supplementation reduced cardiovascular disease (CVD) events in a novel analysis using hierarchical composite CVD outcomes based on win ratio in the VITamin D and OmegA-3 TriaL (VITAL). This was a secondary analysis of our VITAL randomized trial, which assessed the effects of marine n-3 fatty acids (1 g/day) and vitamin D3 on incident CVD and cancer among healthy older adults (n = 25,871). The primary analysis estimated win ratios of a composite of major CVD outcomes prioritized as fatal coronary heart disease, other fatal CVD including stroke, non-fatal myocardial infarction (MI), and non-fatal stroke, comparing n-3 fatty acids to placebo. The primary result was a nonsignificant benefit of this supplementation for the prioritized primary CVD outcome (reciprocal win ratio [95% confidence interval]: 0.90 [0.78-1.04]), similar to the 0.92 (0.80-1.06) hazard ratio in our original time-to-first event analysis without outcome prioritization. Its benefits came from reducing MI (0.71 [0.57-0.88]) but not stroke (1.01 [0.80 to 1.28]) components. For the primary CVD outcome, participants with low fish consumption at baseline benefited (0.79 [0.65-0.96]) more than those with high consumption (1.05 [0.85-1.30]). These results are consistent with, but slightly stronger than, those without outcome prioritization.
| S-EPMC10574231 | biostudies-literature
Project description:BackgroundPredicting complete liberation from mechanical ventilation (MV) is still challenging. Electrical impedance tomography (EIT) offers a non-invasive measure of regional ventilation distribution and could bring additional information.Research questionWhether the display of regional ventilation distribution during a Spontaneous Breathing Trial (SBT) could help at predicting early and successful liberation from MV.Study design and methodsPatients were monitored with EIT during the SBT. The tidal image was divided into ventral and dorsal regions and displayed simultaneously. We explored the ventral-to-dorsal ventilation difference in percentage, and its association with clinical outcomes. Liberation success was defined pragmatically as passing SBT followed by extubation within 24 h without reintubation for 7 days. Failure included use of rescue therapy, reintubation within 7 days, tracheostomy, and not being extubated within 24 h after succesful SBT. A training cohort was used for discovery, followed by a validation cohort.ResultsAmong a total of 98 patients analyzed, 85 passed SBT (87%), but rapid liberation success occurred only in 40; 13.5% of extubated patients required reintubation. From the first minutes to the entire SBT duration, the absolute ventral-to-dorsal difference was consistently smaller in liberation success compared to all subgroups of failure (p < 0.0001). An absolute difference at 5 min of SBT > 20% was associated with failure of liberation, with sensitivity and specificity of 71% and 78% and positive predictive value 81% in a validation cohort.ConclusionDuring SBT, a large ventral-to-dorsal difference in ventilation indicated by EIT may help to rapidly identify patients at risk of liberation failure.
| S-EPMC11705700 | biostudies-literature
Project description:The goal of this study was to evaluate the impact of mechanical ventilation on immune and mitochondrial dysfunctions, in the setting of pneumococcal pneumonia in rabbits. Then, in a randomized trial, we assessed the effect of human umbilical cord-derived mesenchymal stem cells (MSCs), either alone, or in association with an atibiotic treatment (Ceftaroline) in the setting of pneumococcal pneumonia submitted to adverse mechanical ventilation. Pulmonary gene expression was analysed in an attempt to elucidate the effects of MSCs.
2021-04-24 | GSE173238 | GEO