scholarly journals Multivariate meta-analysis model for the difference in restricted mean survival times

Biostatistics ◽  
2019 ◽  
Author(s):  
Isabelle R Weir ◽  
Lu Tian ◽  
Ludovic Trinquart
Keyword(s):  
Meta Analysis ◽  
Analysis Model ◽  
Survival Times ◽  
The Difference

scholarly journals Accuracy in predicting repetitions to task failure in resistance exercise: a scoping review and exploratory meta-analysis

2021 ◽  
Author(s):  
Israel Halperin ◽  
Tomer Malleron ◽  
Itai Har-Nir ◽  
Patroklos Androulakis-Korakakis ◽  
Milo Wolf ◽  
...  
Keyword(s):  
Scoping Review ◽  
Prediction Accuracy ◽  
Meta Analysis ◽  
Upper Body ◽  
Lower Body ◽  
Analysis Model ◽  
Task Failure ◽  
Resistance Exercises ◽  
The Difference ◽  
Training Background

Background: Prescribing repetitions relative to task-failure (TF) is an emerging approach to resistance training. Under this approach, participants terminate the set based on their prediction of the remaining repetitions left to TF. While this approach holds promise, an important step in its development is to deter-mine how accurate participants are in their predictions. That is, what is the difference between the predicted and actual number of repetitions remaining to TF, which ideally should be as small as possible. Objective: Examine the accuracy in predicting repetitions to TF in resistance exercises. Design: Scoping review and exploratory meta-analysis. Search and Inclusion: A systematic literature search was conducted with PubMed, SPORTDiscus, and Google Scholar in January 2021. Inclusion criteria included studies with healthy participants who predicted the number of repetitions they can complete to TF in various resistance exercises, before or during an ongoing set, which was performed to TF. Sixteen publications were eligible for inclusion, of which 13 publications that cover 12 studies were included in our meta-analysis with a total of 414 participants. Results: The main multilevel meta-analysis model including all effects sizes (262 across 12 clusters) revealed that participants tended to under predict the number of repetitions to TF by 0.95 repetitions (95% CIs= 0.17 to 1.73), but with considerable heterogeneity (Q(261)= 3060, p< 0.0001; I2 = 97.9%). Me-ta-regressions showed that prediction accuracy slightly improved when the predictions were made closer to set failure (β= -0.025 [95% CIs= -0.05 to 0.0014]) and when the number of performed to TF was lower (<12 repetitions, β= 0.06 [95% CIs= 0.04 to 0.09]; >12 repetitions, β= 0.47 [95%CIs= 0.44 to 0.49]). Set number trivially influenced prediction accuracy with slightly increased accuracy in later sets (β= -0.07 repetitions [95% CIs= -0.14 to -0.005]). In contrast, participants training status did not seem to influence prediction accuracy (β= -0.006 repetitions [95% CIs= -0.02 to 0.007]) and neither did the implementation of upper or lower body exercises (Upper body – Lower body= -0.58 repetitions [95% CIs -2.32 to 1.16]). Conclusions: Participants were imperfect in their ability to predict proximity to TF independent of their training background. It re-mains to be determined whether the observed degree of inaccuracy should be considered acceptable. De-spite this, prediction accuracies can be improved if they are provided closer to TF, when using heavier loads, or in later sets. To reduce the heterogeneity between studies, future studies should include a clear and detailed account of how TF was explained to participants and how it was confirmed.

Relationship between total plasma homocysteine and the risk of aneurysms – a meta-analysis

VASA ◽  
2020 ◽  
pp. 1-6
Author(s):  
Hanji Zhang ◽  
Dexin Yin ◽  
Yue Zhao ◽  
Yezhou Li ◽  
Dejiang Yao ◽  
...  
Keyword(s):  
Large Scale ◽  
Meta Analysis ◽  
Single Species ◽  
Total Plasma ◽  
Control Groups ◽  
Randomized Controlled ◽  
Randomized Controlled Studies ◽  
The Difference ◽  
The Relationship ◽  
Healthy Participants

Summary: Our meta-analysis focused on the relationship between homocysteine (Hcy) level and the incidence of aneurysms and looked at the relationship between smoking, hypertension and aneurysms. A systematic literature search of Pubmed, Web of Science, and Embase databases (up to March 31, 2020) resulted in the identification of 19 studies, including 2,629 aneurysm patients and 6,497 healthy participants. Combined analysis of the included studies showed that number of smoking, hypertension and hyperhomocysteinemia (HHcy) in aneurysm patients was higher than that in the control groups, and the total plasma Hcy level in aneurysm patients was also higher. These findings suggest that smoking, hypertension and HHcy may be risk factors for the development and progression of aneurysms. Although the heterogeneity of meta-analysis was significant, it was found that the heterogeneity might come from the difference between race and disease species through subgroup analysis. Large-scale randomized controlled studies of single species and single disease species are needed in the future to supplement the accuracy of the results.

Age Differences in Eye Movements During Reading: Degenerative Problems or Compensatory Strategy?

2019 ◽  
Vol 24 (4) ◽  
pp. 297-311
Author(s):  
José David Moreno ◽  
José A. León ◽  
Lorena A. M. Arnal ◽  
Juan Botella
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Meta Analysis ◽  
Age Groups ◽  
Behavioral Changes ◽  
Aging Effects ◽  
Movement Data ◽  
Sentence Reading ◽  
The Difference ◽  
Eye Movements During Reading

Abstract. We report the results of a meta-analysis of 22 experiments comparing the eye movement data obtained from young ( Mage = 21 years) and old ( Mage = 73 years) readers. The data included six eye movement measures (mean gaze duration, mean fixation duration, total sentence reading time, mean number of fixations, mean number of regressions, and mean length of progressive saccade eye movements). Estimates were obtained of the typified mean difference, d, between the age groups in all six measures. The results showed positive combined effect size estimates in favor of the young adult group (between 0.54 and 3.66 in all measures), although the difference for the mean number of fixations was not significant. Young adults make in a systematic way, shorter gazes, fewer regressions, and shorter saccadic movements during reading than older adults, and they also read faster. The meta-analysis results confirm statistically the most common patterns observed in previous research; therefore, eye movements seem to be a useful tool to measure behavioral changes due to the aging process. Moreover, these results do not allow us to discard either of the two main hypotheses assessed for explaining the observed aging effects, namely neural degenerative problems and the adoption of compensatory strategies.

scholarly journals Regional differences in mortality rates during the COVID-19 epidemic in Italy

2020 ◽  
pp. 1-22
Author(s):  
Danila Azzolina ◽  
Giulia Lorenzoni ◽  
Luciano Silvestri ◽  
Ilaria Prosepe ◽  
Paola Berchialla ◽  
...  
Keyword(s):  
Regional Differences ◽  
Southern Italy ◽  
Meta Analysis ◽  
Analysis Data ◽  
Mortality Rates ◽  
Northern Italy ◽  
Admission Rates ◽  
Considerable Impact ◽  
The Difference ◽  
Disease Diffusion

Abstract Objective The COVID-19 outbreak started in Italy on February 20th, 2020, and has resulted in many deaths and intensive care unit (ICU) admissions. This study aimed to illustrate the epidemic COVID-19 growth pattern in Italy by considering the regional differences in disease diffusion during the first three months of the epidemic. Study design and methods Official COVID-19 data were obtained from the Italian Civil Protection Department of the Council of Ministers Presidency. The mortality and ICU admission rates per 100 000 inhabitants were calculated at the regional level and summarized via a Bayesian multilevel meta-analysis. Data were retrieved until April 21st, 2020. Results The highest cumulative mortality rates per 100 000 inhabitants were observed in northern Italy, particularly in Lombardia (85.3, 95% credibility intervals [CI] 75.7–94.7). The difference in the mortality rates between northern and southern Italy increased over time, reaching a difference of 67.72 (95% CI = 66–67) cases on April 2nd. Conclusions Northern Italy showed higher and increasing mortality rates during the first three months of the epidemic. The uncontrolled virus circulation preceding the infection spreading in southern Italy had a considerable impact on system burnout. This experience demonstrates that preparedness against the pandemic is of crucial importance to contain its disruptive effects.

Endothelial nitric oxide synthase polymorphism and venous thromboembolism: A meta-analysis of 9 studies involving 3993 subjects

2021 ◽  
pp. 026835552110166
Author(s):  
Guangbin Huang ◽  
Xuejun Deng ◽  
Yanan Xu ◽  
Pan Wang ◽  
Tao Li ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Venous Thromboembolism ◽  
Nitric Oxide Synthase ◽  
Endothelial Nitric Oxide Synthase ◽  
Meta Analysis ◽  
Enos Polymorphism ◽  
The Difference ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide ◽  
Intron 4

Background Endothelial nitric oxide synthase (eNOS) polymorphism may influence the risk of venous thromboembolism (VTE). However, data from published studies with low statistical power are inconclusive. The present meta-analysis aimed to assess the relationship between eNOS polymorphism and the risk of VTE. Method Case-control studies evaluating the association between the eNOS polymorphism and VTE were searched in PubMed, Embase, Web of Science, Google Scholar, Wanfang, Chinese National Knowledge Infrastructure (CNKI), the Chongqing VIP Chinese Science and Technology Periodical Database (VIP), and Chinese Biomedical Literature Database (CBM). Results A total of 1588 cases and 2405 controls from 9 studies were included in the analysis. The results showed that eNOS G894T polymorphism was related to VTE susceptibility and the difference was statistically significant [T vs G: OR = 1.41, 95% CI (1.13, 1.75), P = 0.002; TT + GG vs TG: OR = 0.71, 95% CI (0.60, 0.84), P = 0.000; TT + TG vs GG: OR = 1.45, 95% CI (1.23, 1.70), P = 0.000]. Additionally, eNOS Intron 4 VNTR polymorphism was related to VTE susceptibility and the difference was statistically significant [4b4b vs 4a4a + 4a4b: OR = 2.77, 95% CI (1.01, 7.61), P = 0.048]. Conclusion ENOS G894T and eNOS Intron 4 VNTR polymorphisms were associated with VTE susceptibility, especially in Asian populations. However, multicenter studies with larger samples should be conducted to further clarify this association and verify our findings.

scholarly journals Effects of Dexmedetomidine as an Analgesic Adjuvant for Surgery of Femur Fracture: A Systematic Review and Meta-Analysis

Pharmacology ◽  
2021 ◽  
pp. 1-9
Author(s):  
Shan Deng ◽  
Yonghao Yu
Keyword(s):  
Femur Fracture ◽  
Meta Analysis ◽  
Sensory Block ◽  
Cochrane Library ◽  
Rescue Analgesia ◽  
Block Level ◽  
Block Time ◽  
Sedation Scores ◽  
The Difference ◽  
The Cochrane Library

Patients who undergo surgery of femur fracture suffer the excruciating pain. Dexmedetomidine (DEX) is a unique α2-adrenergic receptor agonist with sedative and analgesic properties, whose efficacy and safety are still unclear for surgery of femur fracture. Randomized controlled trials comparing the effects of addition of DEX to general or local anesthesia in surgery of femur fracture were searched from MEDLINE, EMBASE, and the Cochrane Library database. Patients who received DEX infusion had a significant longer time to rescue analgesia compared with those without DEX coadministration. DEX treatment seemed to reduce the visual analog score; however, the significance did not reach any statistical difference. DEX as an analgesic adjuvant did not reduce the onset of sensory block time, shorten the time to achieve maximum sensory block level, and provide a longer duration of sensory block. The difference in mean sedation scores between 2 groups was not statistically significant. As for adverse effects, DEX therapy significantly increased the rate of hypotension. In conclusion, dexmedetomidine as a local anesthetic adjuvant in femur fracture surgery had a longer duration of rescue analgesia. However, the incidence of hypotension was markedly increased in these patients. It was worth noting that the evidence was of low to moderate quality.

scholarly journals Discovery and function exploration of microRNA-155 as a molecular biomarker for early detection of breast cancer

Breast Cancer ◽  
2021 ◽  
Author(s):  
Xuemin Liu ◽  
Qingyu Chang ◽  
Haiqiang Wang ◽  
Hairong Qian ◽  
Yikun Jiang
Keyword(s):  
Breast Cancer ◽  
Early Detection ◽  
Protein Interactions ◽  
Meta Analysis ◽  
Enrichment Analysis ◽  
Diagnostic Value ◽  
Diagnostic Biomarker ◽  
Analysis Model ◽  
Sensitivity Specificity ◽  
Function Enrichment

Abstract Background MicroRNA-155 (miR-155) may function as a diagnostic biomarker of breast cancer (BC). Nevertheless, the available evidence is controversial. Therefore, we performed this study to summarize the global predicting role of miR-155 for early detection of BC and preliminarily explore the functional roles of miR-155 in BC. Methods We first collected published studies and applied the bivariate meta-analysis model to generate the pooled diagnostic parameters of miR-155 in diagnosing BC such as sensitivity, specificity and area under curve (AUC). Then, we applied function enrichment and protein–protein interactions (PPI) analyses to explore the potential mechanisms of miR-155. Results A total of 21 studies were finally included. The results indicated that miR-155 allowed for the discrimination between BC patients and healthy controls with a sensitivity of 0.87 (95% CI 0.78–0.93), specificity of 0.82 (0.72–0.89), and AUC of 0.91 (0.88–0.93). In addition, the overall sensitivity, specificity and AUC for circulating miR-155 were 0.88 (0.76–0.95), 0.83 (0.72–0.90), and 0.92 (0.89–0.94), respectively. Function enrichment analysis revealed several vital ontologies terms and pathways associated with BC occurrence and development. Furthermore, in the PPI network, ten hub genes and two significant modules were identified to be involved in some important pathways associated with the pathogenesis of BC. Conclusions We demonstrated that miR-155 has great potential to facilitate accurate BC detection and may serve as a promising diagnostic biomarker for BC. However, well-designed cohort studies and biological experiments should be implemented to confirm the diagnostic value of miR-155 before it can be applied to routine clinical procedures.

scholarly journals Simultaneous implant placement with autogenous onlay bone grafts: a systematic review and meta-analysis

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Guoqiang Ma ◽  
Chaoan Wu ◽  
Miaoting Shao
Keyword(s):  
Meta Analysis ◽  
Survival Rates ◽  
Bone Grafts ◽  
Implant Survival ◽  
Analysis Model ◽  
Implant Placement ◽  
Significant Difference ◽  
Delayed Implant Placement ◽  
Onlay Grafts

AbstractSeveral authors have suggested that implants can be placed simultaneously with onlay bone grafts without affecting outcomes. Therefore, the purpose of this study was to answer the following clinical questions: (1) What are the outcomes of implants placed simultaneously with autogenous onlay bone grafts? And (2) is there a difference in outcomes between simultaneous vs delayed placement of implants with autogenous onlay bone grafts? Databases of PubMed, Embase, and Google Scholar were searched up to 15 November 2020. Data on implant survival was extracted from all the included studies (single arm and comparative) to calculate point estimates with 95% confidence intervals (CI) and pooled using the DerSimonian–Laird meta-analysis model. We also compared implant survival rates between the simultaneous and delayed placement of implants with data from comparative studies. Nineteen studies were included. Five of them compared simultaneous and delayed placement of implants. Dividing the studies based on follow-up duration, the pooled survival of implant placed simultaneously with onlay grafts after <2.5 years of follow-up was 93.1% (95% CI 82.6 to 97.4%) and after 2.5–5 years was 86% (95% CI 78.6 to 91.1%). Implant survival was found to be 85.8% (95% CI 79.6 to 90.3%) with iliac crest grafts and 95.7% (95% CI 83.9 to 93.0%) with intra-oral grafts. Our results indicated no statistically significant difference in implant survival between simultaneous and delayed placement (OR 0.43, 95% 0.07, 2.49, I2=59.04%). Data on implant success and bone loss were limited. Data indicates that implants placed simultaneously with autogenous onlay grafts have a survival rate of 93.1% and 86% after a follow-up of <2.5 years and 2.5–5years respectively. A limited number of studies indicate no significant difference in implant survival between the simultaneous and delayed placement of implants with onlay bone grafts. There is a need for randomized controlled trials comparing simultaneous and delayed implant placement to provide robust evidence.

First models for structural energy transmission decoupling in the high frequency regime under aerodynamic excitations

2021 ◽  
pp. 095440622110200
Author(s):  
G Mazzeo ◽  
MN Ichchou ◽  
G Petrone ◽  
O Bareille ◽  
S De Rosa ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Vibrational Energy ◽  
Complex Structure ◽  
Structural Response ◽  
Test Case ◽  
Analysis Model ◽  
Quick Method ◽  
Vibrational Velocity ◽  
Frequency Regime ◽  
The Difference

In the wind tunnel facility, a test structure is often used for measuring its vibrational response to the aerodynamic excitation. A support is needed to sustaining the structure and it is mandatory that this support does not influence the vibrational energy to be measured. To this aim, the maximum amount of energy decoupling between the structure and the support is desired. This work is focused around a quick method to estimate this decoupling by using simplified models for the Turbulent Boundary Layer (TBL) excitation and for the structural response. Specifically, the Equivalent Rain-on-the-roof excitation is invoked with a Statistical Energy Analysis model for the structure. Some simple design rules are proposed and based on little information leading to foresee the difference of vibrational velocity levels between the two structural systems. A simplified test-case is used for the first investigations and a complex structure is finally conceived thinking to vibroacoustic measurements in a large wind tunnel facility. Although some results are largely expected, the global approach is promising.

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