Tag: statistics

J Matern Fetal Neonatal Med. 2021 Apr 1:1-5. doi: 10.1080/14767058.2020.1863362. Online ahead of print.

ABSTRACT

Objectives: Treatment of essential thrombocythemia (ET) is particularly challenging in pregnancy due to the increased risk of thromboembolic complications. Therefore, the use of antithrombotic regimens are recommended in pregnant women with ET.Methods: The study included 52 pregnancies in 27 patients diagnosed with ET, who were treated in Department of Haematology. The influence of anticoagulant, antiplatelet and cytoreductive therapy on the course and outcome of pregnancy was analysed. This study also examined if there was any correlation between molecular and clinical features such as mutational profile, blood count, presence of acquired von Willebrand syndrome (AvWS), the International Prognostic Score for Essential Thrombocythemia (IPSET) risk group and the IPSET-thrombosis risk group and pregnancy outcome.Results: Study participants who received antithrombotic therapy were significantly more likely to give birth to a healthy child. The best outcomes were observed in patients who received low dose acetylsalicylic acid (ASA) together with low-molecular-weight heparin (LMWH). There was a statistically significant correlation between classification to the high-risk group according to the IPSET-thrombosis score and incidence of miscarriage. Cytoreductive treatment with interferon-α2, as well as the presence of AvWS did not increase the likelihood of pregnancy loss. Blood counts and presence of specific gene mutations profile were also not found to be significant determinants of pregnancy outcome.Conclusion: To our best knowledge, this is the first clinical study investigating the correlation between risk group (according to IPSET and IPSET-thrombosis) and pregnancy outcome in women with ET.

PMID:33792458 | DOI:10.1080/14767058.2020.1863362

J Appl Physiol (1985). 2021 Apr 1. doi: 10.1152/japplphysiol.01084.2020. Online ahead of print.

ABSTRACT

Hyperbaric oxygen therapy has been proposed as a method to treat traumatic brain injuries. The combination of pressure and increased oxygen concentration produces a higher content of dissolved oxygen in the bloodstream, which could generate a therapeutic benefit for brain injuries. This dissolved oxygen penetrates deeper into damaged brain tissue than otherwise possible and promotes healing. The result includes improved cognitive functioning and an alleviation of symptoms. However, randomized controlled trials have failed to produce consistent conclusions across multiple studies. There are numerous explanations that might account for the mixed evidence, although one possibility is that prior evidence focuses primarily on statistical significance. The current analyses explored existing evidence by calculating an effect size from each active treatment group and each control group among previous studies. An effect size measure offers several advantages when comparing across studies as it can be used to directly contrast evidence from different scales, and it provides a proximal measure of clinical significance. When exploring the therapeutic benefit through effect sizes, there was a robust and consistent benefit to individuals who underwent hyperbaric oxygen therapy. Placebo effects from the control condition could account for approximately one-third of the observed benefits, but there appeared to be a clinically significant benefit to using hyperbaric oxygen therapy as a treatment intervention for traumatic brain injuries. This evidence highlights the need for design improvements when exploring interventions for traumatic brain injury as well as the importance of focusing on clinical significance in addition to statistical significance.

PMID:33792399 | DOI:10.1152/japplphysiol.01084.2020

Rev Cardiovasc Med. 2021 Mar 30;22(1):215-223. doi: 10.31083/j.rcm.2021.01.20216.

ABSTRACT

Both Transthoracic echocardiography (TTE) and cardiac magnetic resonance (CMR) have well-established role in mitral regurgitation (MR) quantification for optimal management strategy. We assessed the correlation between TTE and CMR in the quantification of MR. Participants with isolated MR and echocardiographic mitral regurgitant volume (RVol) ≥ 30 mL/beat were included. A consecutive sample of 30 participants (Mean age 52.7 ± 19.3 years, 50% males) was selected and referred for indirect and direct CMR quantification of mitral RVol. There was a statistically significant strong positive correlation between the echocardiographic and indirect CMR quantification of the mitral RVol (r = 0.753, P < 0.001) and a statistically significant moderate positive correlation between the echocardiographic and direct CMR quantification of the mitral RVol (r = 0.530, P < 0.003). The inter-observer reliability of the MR grade between TTE and CMR showed a statistically significant moderate agreement (κ = 0.502, P = 0.0001) when the observers used the echocardiographic mitral RVol for grading of MR. On the other hand, the inter-observer reliability of the MR grade between TTE and CMR showed a statistically significant faint agreement (κ = 0.251, P = 0.024) when the observers used the echocardiographic regurgitant fraction (RF) for grading of MR. The positive reciprocal relationship between the CMR and the TTE highlights the potential role of the CMR as a concomitant imaging tool for quantification of the mitral RVol and grading of isolated MR, especially with limited or inconclusive TTE studies. This will enhance the management strategy and improve outcomes.

PMID:33792265 | DOI:10.31083/j.rcm.2021.01.20216

Rev Cardiovasc Med. 2021 Mar 30;22(1):239-245. doi: 10.31083/j.rcm.2021.01.103.

ABSTRACT

The burden of cardiovascular disease is predicted to escalate in developing countries. The aim of this study is to assess the characteristics, management strategies and outcomes of the patients with acute coronary syndrome (ACS) who were admitted to hospitals under the chest pain center mode in southwest P. R. China. Adults hospitalized with a diagnosis of ACS were enrolled in the retrospective, observational registry between January 2017 and June 2019 at 11 hospitals in Chengdu, P. R. China. The collected data included the patients’ baseline characteristics, clinical management and in-hospital outcomes. After Statistical analysis, (1) A total of 2857 patients with ACS, among which 1482 have ST-segment elevation myocardial infarction (STEMI), 681 have non-STEMI (NSTEMI) and 694 have unstable angina (UA) were enrolled in the study. (2) 61.3% of the ACS patients received reperfusion therapy. More patients with STEMI underwent percutaneous coronary intervention (PCI) compared with NSTEMI/UA patients (80.6% vs. 38.8%, P < 0.001), while thrombolytics were administered in only 1.8% of STEMI patients. (3) The median time from symptoms to hospital was 190 min (IQR 94-468) in STEMI, 283 min (IQR 112-1084) in NSTEMI and 337 min (IQR 97-2220) in UA (P < 0.001), and the door-to-balloon time for primary PCI (pPCI) was 85 min (IQR 55-121) in STEMI. (4) The in-hospital outcomes for STEMI patients included death (8.1%) and acute heart failure (22.6%), while the outcomes for those with NSTEMI and UA were better: death (4.0% and 0.9%, P < 0.001) and acute heart failure (15.3% and 9.9%, P < 0.001). (5) Antiplatelet drugs, lipid-lowering drugs, β-blockers and angiotensin-converting enzyme inhibitors (ACEI) /angiotensin receptor blockers (ARB) were used in about 98.3%, 95.0%, 67.7% and 54.3% of the ACS patients, respectively. Therefore, the management capacity in Chengdu has relatively increased compared with previous studies, but important gaps still exist compared with developed countries, especially regarding the management of the NSTEMI/UA patients.

PMID:33792268 | DOI:10.31083/j.rcm.2021.01.103

Chem Rev. 2021 Apr 1. doi: 10.1021/acs.chemrev.0c01304. Online ahead of print.

ABSTRACT

Polymer networks are complex systems consisting of molecular components. Whereas the properties of the individual components are typically well understood by most chemists, translating that chemical insight into polymer networks themselves is limited by the statistical and poorly defined nature of network structures. As a result, it is challenging, if not currently impossible, to extrapolate from the molecular behavior of components to the full range of performance and properties of the entire polymer network. Polymer networks therefore present an unrealized, important, and interdisciplinary opportunity to exert molecular-level, chemical control on material macroscopic properties. A barrier to sophisticated molecular approaches to polymer networks is that the techniques for characterizing the molecular structure of networks are often unfamiliar to many scientists. Here, we present a critical overview of the current characterization techniques available to understand the relation between the molecular properties and the resulting performance and behavior of polymer networks, in the absence of added fillers. We highlight the methods available to characterize the chemistry and molecular-level properties of individual polymer strands and junctions, the gelation process by which strands form networks, the structure of the resulting network, and the dynamics and mechanics of the final material. The purpose is not to serve as a detailed manual for conducting these measurements but rather to unify the underlying principles, point out remaining challenges, and provide a concise overview by which chemists can plan characterization strategies that suit their research objectives. Because polymer networks cannot often be sufficiently characterized with a single method, strategic combinations of multiple techniques are typically required for their molecular characterization.

PMID:33792299 | DOI:10.1021/acs.chemrev.0c01304

Cytoskeleton (Hoboken). 2021 Apr 1. doi: 10.1002/cm.21659. Online ahead of print.

ABSTRACT

Rho-GTPase-activating proteins (Rho-GAPs) are essential upstream regulators of the Rho family of GTPases. Currently, it remains unclear if the phenotypic change caused by perturbations to a Rho-GAP is predictable from its amino acid sequence. Here we analyze the relationship between the morphological response of cells to the silencing of Rho-GAPs and their primary structure. For all possible pairs of 57 different Rho-GAPs expressed in MCF10A epithelial cells, the similarity in the Rho-GAP silencing-induced morphological change was quantified and compared to the similarity in the primary structure of the corresponding pairs. We found a distinct correlation between the morphological and sequence similarities in a specific group of RhoA-targeting Rho-GAPs. Thus, the family-wide analysis revealed a common feature shared by the specific Rho-GAPs. This article is protected by copyright. All rights reserved.

PMID:33792196 | DOI:10.1002/cm.21659

Rev Cardiovasc Med. 2021 Mar 30;22(1):159-165. doi: 10.31083/j.rcm.2021.01.238.

ABSTRACT

Coronavirus Disease 2019 (COVID-19) originated in Wuhan, China in December 2019 and rapidly spread worldwide. Herein, we conducted a systematic review and meta-analysis to find the association between COVID-19 and cardiovascular complications. We conducted a systematic literature search of the PubMed and Embase databases from 01 December 2019 to 30 November 2020. We then statistically analyzed the incidence of cardiovascular complications in COVID-19 patients. We included 3044 confirmed COVID-19 cases from 12 studies. The most common cardiovascular complications in COVID-19 patients were myocardial injury (21.2%, 95% CI 12.3-30.0%) and arrhythmia (15.3%, 95% CI 8.4-22.3%), followed by heart failure (14.4%, 95% CI 5.7-23.1%) and acute coronary syndrome (1.0%, 95% CI 0.5-1.5%). The pooled incidence of heart failure, arrhythmia and myocardial injury in non-survivors were 47.8% (95% CI 41.4-54.2%), 40.3% (95% CI 1.6-78.9%) and 61.7% (95% CI 46.8-76.6%), respectively. Also, the data separately showed significantly higher incidence of heart failure and cardiac injury in non-survivors (relative risks = 5.13, 95% CI 2.46-10.7, Z = 4.36, P = 0.017) and (relative risks = 6.91, 95% CI 3.19-14.95, Z = 4.91, P = 0.009). Myocardial injury and arrhythmia were the most common complications in COVID-19 patients. Myocardial injury and heart failure were more common in patients who died, regardless of a history of cardiovascular disease. The incidence of heart failure and myocardial injury were higher in non-survivors compared to the survivors. Accordingly, in addition to basic support, cardiac reactions of patients with confirmed COVID-19 with or without underlying cardiovascular diseases should be closely monitored.

PMID:33792257 | DOI:10.31083/j.rcm.2021.01.238

Rev Cardiovasc Med. 2021 Mar 30;22(1):207-213. doi: 10.31083/j.rcm.2021.01.288.

ABSTRACT

Cardiopulmonary bypass (CPB) may trigger organs damage, including kidney injury, due to a massive cytokine release. In this observational, prospective study, we analyzed the possible impact of chronic treatment with ACE-Inhibitors (ACE-I) on the inflammatory response and renal function after CPB. Sixty-nine patients undergoing major cardiac surgery with CPB were enrolled. Patients were stratified according to long-term (> 6 mo.) ACE-I use (n = 38) or not (n = 31). The primary endpoint was the change in IL-1alpha, IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, TNF alpha, EGF and VEGF plasma levels. Secondary (renal) endpoints were postoperative acute kidney injury (AKI), recovery of baseline GFR values and the absolute changes in renal function indexes. After CPB, IL-1alpha, IL-1beta, IL-4 and TNF-alpha remained stable over time while a significant decrease in IL-2 levels was noticed in the ACE-I group (p = 0.01). IL-6 and IL-8 increased after surgery and tended to decrease after 48 h. IL-10 levels showed a similar variation, but both their rise and decrease were more pronounced in patients under ACE-I treatment (p = 0.007). Finally, VEGF and EGF showed a marked initial decrease with a tendency to normalization 10 days after surgery (p for trend ranging from 0.01 to 0.001). The occurrence of AKI within 2 days after surgery, the rate of GFR recovery and the absolute changes in renal function indexes were not statistically different between groups. Chronic, long-term ACE-I treatment may influence the inflammatory response following CPB. On the other hand, this drug class apparently has neutral impact on perioperative renal outcomes.

PMID:33792264 | DOI:10.31083/j.rcm.2021.01.288

J Spec Pediatr Nurs. 2021 Mar 31:e12332. doi: 10.1111/jspn.12332. Online ahead of print.

ABSTRACT

PURPOSE: The purpose of this study is to describe nursing staff perspectives about caring for children with autism spectrum disorders (ASD) in the hospital, strategies they use to support care, and relationships between these factors.

DESIGN AND METHODS: A descriptive, cross-sectional survey design with nursing staff at a large pediatric hospital system in the United States was employed. The researcher-designed, pilot-tested survey assessed participant demographics, knowledge about ASD, perceived effectiveness caring for children with ASD, previous training, and current strategy use. Data analysis involved descriptive statistics, correlations, and group comparisons based on interaction frequency with the population and previous training.

RESULTS: The participants involved 90 pediatric hospital nursing staff members providing direct care. Respondents demonstrated 90% accurate knowledge of the characteristics of ASD. Self-reported effectiveness in caring for children with ASD did not correlate with knowledge and significantly correlated with an increased number of strategies. Nursing staff with frequent interaction with people with ASD or those with previous training reported significantly more strategies to care for children with ASD. Only 35% of participants reported that they have adequate strategies to care for children with ASD in the hospital.

PRACTICE IMPLICATIONS: Having more strategies was the factor associated with higher self-efficacy, so training for nursing staff should focus on increasing the number of strategies to use with children with ASD in the hospital and provide mechanisms to collaborate with other professionals to individualize strategies to meet each child’s needs.

PMID:33792139 | DOI:10.1111/jspn.12332

Pharm Stat. 2021 Apr 1. doi: 10.1002/pst.2122. Online ahead of print.

ABSTRACT

Sample size calculations in clinical trials need to be based on profound parameter assumptions. Wrong parameter choices may lead to too small or too high sample sizes and can have severe ethical and economical consequences. Adaptive group sequential study designs are one solution to deal with planning uncertainties. Here, the sample size can be updated during an ongoing trial based on the observed interim effect. However, the observed interim effect is a random variable and thus does not necessarily correspond to the true effect. One way of dealing with the uncertainty related to this random variable is to include resampling elements in the recalculation strategy. In this paper, we focus on clinical trials with a normally distributed endpoint. We consider resampling of the observed interim test statistic and apply this principle to several established sample size recalculation approaches. The resulting recalculation rules are smoother than the original ones and thus the variability in sample size is lower. In particular, we found that some resampling approaches mimic a group sequential design. In general, incorporating resampling of the interim test statistic in existing sample size recalculation rules results in a substantial performance improvement with respect to a recently published conditional performance score.

PMID:33792167 | DOI:10.1002/pst.2122