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Critical Care (London, England) Aug 2023Ventilator-free days (VFDs) are a composite endpoint increasingly used as the primary outcome in critical care trials. However, because of the skewed distribution and...
BACKGROUND
Ventilator-free days (VFDs) are a composite endpoint increasingly used as the primary outcome in critical care trials. However, because of the skewed distribution and competitive risk between components, sample size estimation remains challenging. This systematic review was conducted to systematically assess whether the sample size was congruent, as calculated to evaluate VFDs in trials, with VFDs' distribution and the impact of alternative methods on sample size estimation.
METHODS
A systematic literature search was conducted within the PubMed and Embase databases for randomized clinical trials in adults with VFDs as the primary outcome until December 2021. We focused on peer-reviewed journals with 2021 impact factors greater than five. After reviewing definitions of VFDs, we extracted the sample size and methods used for its estimation. The data were collected by two independent investigators and recorded in a standardized, pilot-tested forms tool. Sample sizes were calculated using alternative statistical approaches, and risks of bias were assessed with the Cochrane risk-of-bias tool.
RESULTS
Of the 26 clinical trials included, 19 (73%) raised "some concerns" when assessing risks of bias. Twenty-four (92%) trials were two-arm superiority trials, and 23 (89%) were conducted at multiple sites. Almost all the trials (96%) were unable to consider the unique distribution of VFDs and death as a competitive risk. Moreover, significant heterogeneity was found in the definitions of VFDs, especially regarding varying start time and type of respiratory support. Methods for sample size estimation were also heterogeneous, and simple models, such as the Mann-Whitney-Wilcoxon rank-sum test, were used in 14 (54%) trials. Finally, the sample sizes calculated varied by a factor of 1.6 to 17.4.
CONCLUSIONS
A standardized definition and methodology for VFDs, including the use of a core outcome set, seems to be required. Indeed, this could facilitate the interpretation of findings in clinical trials, as well as their construction, especially the sample size estimation which is a trade-off between cost, ethics, and statistical power. Systematic review registration PROSPERO ID: CRD42021282304. Registered 15 December 2021 ( https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42021282304 ).
Topics: Adult; Humans; Sample Size; Ventilators, Mechanical; Critical Care
PubMed: 37528425
DOI: 10.1186/s13054-023-04562-y -
TheScientificWorldJournal 2024Multilevel models have gained immense popularity across almost every discipline due to the presence of hierarchy in most data and phenomena. In this paper, we present a...
INTRODUCTION
Multilevel models have gained immense popularity across almost every discipline due to the presence of hierarchy in most data and phenomena. In this paper, we present a systematic review on the adoption and application of multilevel models and the important information reported on the results generated from the use of these models.
METHODS
The review was performed by searching Google Scholar for original research articles on the application of multilevel models published between 2010 and 2020. The search strategy involved topics such as "multilevel models," "hierarchical linear models," and "mixed models with hierarchy." The search placed more emphasis on the application of hierarchical models in any discipline but excluded software methodological development and related articles.
RESULTS
A total of 121 articles were initially obtained from the search results. However, 65 articles met the inclusion criteria for the review. Out of the 65 articles reviewed, 46.2% were related to health/epidemiology, 15.4% to education and psychology, and 16.9% to social life. The majority of the articles (78.5%) were two-level models, and most of these studies modelled univariate responses. However, the few that modelled more than one response modelled them separately. Moreover, 83.1% were cross-sectional design, and 9.2% and 6.2% were longitudinal and repeated measures, respectively. Moreover, a little over half (55.4%) of articles reported on the intraclass correlation measure, and all articles indicated the response variable distribution where most (47.7%) were normally distributed. Only 58.5% of articles reported on the estimation methods used as Bayesian (20%) and MLE (18.5%). Again, model validation measures and statistical software were reported in 70.8% and 90.8% articles, respectively.
CONCLUSION
There is an increase in the utilization of multilevel modelling in the last decade, which could be attributed to the presence of clustered and hierarchically correlated data structures. There is a need for improvement in the area of measurement and reporting on the intraclass correlation, parameter estimation, and variable selection measures to further improve the quality of the application of multilevel models. The integration of spatial effects into multilevel models is very limited and needs to be explored in the future.
PubMed: 38495479
DOI: 10.1155/2024/4658333 -
PloS One 2024Machine perfusion (MP) is often referred to as one of the most promising advancements in liver transplantation research of the last few decades, with various techniques...
Machine perfusion (MP) is often referred to as one of the most promising advancements in liver transplantation research of the last few decades, with various techniques and modalities being evaluated in preclinical studies using animal models. However, low scientific rigor and subpar reporting standards lead to limited reproducibility and translational potential, hindering progress. This pre-registered systematic review (PROSPERO: CRD42021234667) aimed to provide a thematic overview of the preclinical research landscape on MP in liver transplantation using in vivo transplantation models and to explore methodological and reporting standards, using the ARRIVE (Animal Research: Reporting of In Vivo Experiments) score. In total 56 articles were included. Studies were evenly distributed across Asia, Europe, and the Americas. Porcine models were used in 57.1% of the studies, followed by rats (39.3%) and dogs (3.6%). In terms of graft type, 55.4% of the studies used donation after cardiac death grafts, while donation after brain death grafts accounted for 37.5%. Regarding MP modalities, the distribution was as follows: 41.5% of articles utilized hypothermic MP, 21.5% normothermic MP, 13.8% subnormothermic MP, and 16.9% utilized hypothermic oxygenated MP. The stringent documentation of ARRIVE elements concerning precise experimental execution, group size and selection, the choice of statistical methods, as well as adherence to the principles of the 3Rs, was notably lacking in the majority of publications, with less than 30% providing comprehensive details. Postoperative analgesia and antibiotics treatment were not documented in 82.1% of all included studies. None of the analyzed studies fully adhered to the ARRIVE Guidelines. In conclusion, the present study emphasizes the importance of adhering to reporting standards to promote reproducibility and adequate animal welfare in preclinical studies in machine perfusion. At the same time, it highlights a clear deficiency in this field, underscoring the need for further investigations into animal welfare-related topics.
Topics: Swine; Animals; Dogs; Rats; Reproducibility of Results; Organ Preservation; Liver; Perfusion; Liver Transplantation
PubMed: 38329986
DOI: 10.1371/journal.pone.0297942 -
Environmental Management Mar 2024Ecosystem services (ES) embrace contributions of nature to human livelihood and well-being. Reef environments provide a range of ES with direct and indirect...
Ecosystem services (ES) embrace contributions of nature to human livelihood and well-being. Reef environments provide a range of ES with direct and indirect contributions to people. However, the health of reef environments is declining globally due to local and large-scale threats, affecting ES delivery in different ways. Mapping scientific knowledge and identifying research gaps on reefs' ES is critical to guide their management and conservation. We conducted a systematic assessment of peer-reviewed articles published between 2007 and 2022 to build an overview of ES research on reef environments. We analyzed the geographical distribution, reef types, approaches used to assess ES, and the potential drivers of change in ES delivery reported across these studies. Based on 115 articles, our results revealed that coral and oyster reefs are the most studied reef ecosystems. Cultural ES (e.g., subcategories recreation and tourism) was the most studied ES in high-income countries, while regulating and maintenance ES (e.g., subcategory life cycle maintenance) prevailed in low and middle-income countries. Research efforts on reef ES are biased toward the Global North, mainly North America and Oceania. Studies predominantly used observational approaches to assess ES, with a marked increase in the number of studies using statistical modeling during 2021 and 2022. The scale of studies was mostly local and regional, and the studies addressed mainly one or two subcategories of reefs' ES. Overexploitation, reef degradation, and pollution were the most commonly cited drivers affecting the delivery of provisioning, regulating and maintenance, and cultural ES. With increasing threats to reef environments, the growing demand for assessing the contributions to humans provided by reefs will benefit the projections on how these ES will be impacted by anthropogenic pressures. The incorporation of multiple and synergistic ecosystem mechanisms is paramount to providing a comprehensive ES assessment, and improving the understanding of functions, services, and benefits.
Topics: Animals; Humans; Ecosystem; Coral Reefs; Conservation of Natural Resources; Anthozoa; Models, Statistical
PubMed: 38006452
DOI: 10.1007/s00267-023-01912-y -
Journal of Neurosurgery. Pediatrics Jun 2024Brain tumors are a global problem, leading to higher cancer-related morbidity and mortality rates in children. Despite the progressive though slow advances in... (Meta-Analysis)
Meta-Analysis
OBJECTIVE
Brain tumors are a global problem, leading to higher cancer-related morbidity and mortality rates in children. Despite the progressive though slow advances in neuro-oncology care, research, and diagnostics in sub-Saharan Africa (SSA), the epidemiological landscape of pediatric brain tumors (PBTs) remains underestimated. This study aimed to systematically analyze the distribution of PBT types in SSA.
METHODS
Ovid Medline, Global Index Medicus, African Journals Online, Google Scholar, and faculty of medicine libraries were searched for literature on PBTs in SSA published before October 29, 2022. A proportional meta-analysis was performed.
RESULTS
Forty-nine studies, involving 2360 children, met the inclusion criteria for review; only 20 (40.82%) were included in the quantitative analysis. South Africa and Nigeria were the countries with the most abundant data. Glioma not otherwise specified (NOS) was the common PBT in the 4 SSA regions combined. However, medulloblastoma was more commonly reported in Southern SSA (p = 0.01) than in other regions. The prevalence and the overall pooled proportion of the 3 common PBTs was estimated at 46.27% and 0.41 (95% CI 0.32-0.50, 95% prediction interval [PI] 0.11-0.79), 25.34% and 0.18 (95% CI 0.14-0.21, 95% PI 0.06-0.40), and 12.67% and 0.12 (95% CI 0.09-0.15, 95% PI 0.04-0.29) for glioma NOS, medulloblastoma, and craniopharyngioma, respectively. Sample size moderated the estimated proportion of glioma NOS (p = 0.02). The highest proportion of craniopharyngiomas was in Western SSA, and medulloblastoma and glioma NOS in Central SSA.
CONCLUSIONS
These findings provide insight into the trends of PBT types and the proportion of the top 3 most common tumors across SSA. Although statistical conclusions are difficult due to the inconsistency in the data, the study identifies critical areas for policy development and collaborations that can facilitate improved outcomes in PBTs in SSA. More accurate epidemiological studies of these tumors are needed to better understand the burden of the disease and the geographic variation in their distribution, and to raise awareness in their subsequent management.
Topics: Humans; Brain Neoplasms; Africa South of the Sahara; Child; Glioma; Child, Preschool; Adolescent; Prevalence; Medulloblastoma; Craniopharyngioma; Infant
PubMed: 38489811
DOI: 10.3171/2024.1.PEDS23282 -
Cureus Feb 2024Total knee arthroplasty is one of the most common orthopedic procedures. Simultaneous bilateral knee arthroplasty involves performing total knee arthroplasty on both... (Review)
Review
Total knee arthroplasty is one of the most common orthopedic procedures. Simultaneous bilateral knee arthroplasty involves performing total knee arthroplasty on both knees in a single anesthetic session. This systematic review and meta-analysis followed the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020. A primary search was performed using PubMed, EBSCO, Scopus, Web of Science, Clarivate, and Google Scholar databases. Quantitative data synthesis was performed using MedCalc® Statistical Software version 20.115 to determine the pooled prevalence of the infection among patients who underwent simultaneous bilateral knee arthroplasty. The Newcastle-Ottawa Scale was used to assess study quality. We included 30 studies in our quantitative data synthesis, with a total population of 118,502 patients (237,004 knees). The pooled prevalence of superficial infection, deep infection, and unspecified surgical site infection was estimated to be 0.86% (95% confidence interval: 0.62-1.13%), 0.84% (95% confidence interval: 0.64-1.05%), and 1.18% (95% confidence interval: 0.45-2.27%), respectively. There was significant heterogeneity (I2 >50%) in all analyses, and inspection of funnel plots revealed a symmetrical distribution of plotted data. We found that the infection rates following simultaneous bilateral knee arthroplasty were relatively low but heterogeneous, as the data showed marked variability. Superficial infections were more common than deep infections; however, there was a small difference in their prevalence. Furthermore, the reliability of our findings was limited owing to significant heterogeneity.
PubMed: 38487132
DOI: 10.7759/cureus.54117 -
Cureus Apr 2024In critical care medicine, research trials serve as crucial avenues for disseminating knowledge, influencing clinical practices, and fostering innovation. Notably, a... (Review)
Review
In critical care medicine, research trials serve as crucial avenues for disseminating knowledge, influencing clinical practices, and fostering innovation. Notably, a significant gender imbalance exists within this field, potentially mirrored in the authorship of critical care research. This study aimed to investigate an exploration to ascertain the presence and extent of female representation in first and senior authorship roles within critical care literature. To this end, a systematic search was conducted across PubMed, Google Scholar, and Web of Science databases for original articles published up to February 2024, coupled with a methodological quality assessment via the Newcastle-Ottawa Scale (NOS) and statistical analyses through Review Manager software (RevMan, version 5.4.1, The Cochrane Collaboration, 2020). The study's findings, distilled from seven studies included in the final analysis, reveal a pronounced gender disparity. Specifically, in critical care literature examining mixed populations, female first authors were significantly less common than their male counterparts, with an odds ratio (OR) of 4.25 (95% confidence interval (CI): 3.18-5.68; p < 0.00001). Conversely, pediatric critical care studies did not show a significant difference in gender distribution among first authors (OR: 1.37; 95% CI: 0.31-6.10; p = 0.68). The investigation also highlighted a stark underrepresentation of female senior authors in critical care research across both mixed (OR: 11.67; 95% CI: 7.76-17.56; p < 0.00001) and pediatric populations (OR: 5.41; 95% CI: 1.88-15.56; p = 0.002). These findings underscore the persistent underrepresentation of women in critical care literature authorship and their slow progression into leadership roles, as evidenced by the disproportionately low number of female senior authors.
PubMed: 38707086
DOI: 10.7759/cureus.57528 -
BMC Public Health Apr 2024Dementia is one of the major causes of disability and dependency among older people worldwide. The formation of an aging population in Iran can be associated with... (Meta-Analysis)
Meta-Analysis
BACKGROUND
Dementia is one of the major causes of disability and dependency among older people worldwide. The formation of an aging population in Iran can be associated with societal problems, including age-related disorders such as dementia. This study aimed to estimate the prevalence of dementia& Alzheimer disease in adults aged 60 years or older and it's its geographical distribution in Iran.
METHODS
A systematic review and meta-analysis study included articles published in both English and Persian languages and utilized various databases including: Google Scholar, PubMed, Web of Science, Magiran, and thesis database of medicine universities up to December 2022. The pooled prevalence was calculated using random effects models. The prevalence was reported separately for different geographical locations and types of area sampling, and age adjustment was performed for the selected studies. All statistical analyses were conducted using metaprop package in STATA version 17. The I2 statistic was applied to assess heterogeneity.
RESULTS
The meta-analysis considered nine relevant studies that were carried out up to 2023 in Iran. The study found that the prevalence of dementia in central and east counties was estimated to be 0.14 (95% CI; 0.04-0.31), while in western counties, the prevalence was estimated to be 0.1 (95%CI; 0.01-0.27). The estimated overall crude prevalence of dementia was estimated at 0.14 (95% CI; 0.03-0.31). Estimated prevalence-based health centers sampling and hospital-based studies were 0.02 (95% CI; 0.02-0.03), 0.05 (95% CI 0.06-0.11), respectively. One study used nursing home sampling as the sampling method, and the estimated prevalence was 0.43 (95%CI 0.38-0.49).
CONCLUSION
This is the first systematic review and meta-analysis of the prevalence of dementia's disease up to 2023 in Iran. The estimated overall prevalence of dementia is lower than the reported prevalence in European countries and similar to other Asian countries.
Topics: Humans; Iran; Dementia; Prevalence; Aged; Middle Aged; Aged, 80 and over; Male; Female
PubMed: 38664651
DOI: 10.1186/s12889-024-18415-y -
Cureus May 2024Novel hybrid approaches for chest wall irradiation show promising outcomes regarding target coverage and sparing organs at risk (OARs). In this systematic review, we... (Review)
Review
Hybrid Treatment Planning for Chest Wall Irradiation Utilizing Three-Dimensional Conformal Radiotherapy (3DCRT), Intensity-Modulated Radiation Therapy (IMRT), and Volumetric Modulated Arc Therapy (VMAT): A Systematic Review.
Novel hybrid approaches for chest wall irradiation show promising outcomes regarding target coverage and sparing organs at risk (OARs). In this systematic review, we compared hybrid volumetric modulated arc therapy (H-VMAT) or hybrid intensity-modulated radiotherapy (H-IMRT) techniques with non-hybrid techniques, such as three-dimensional conformal radiation therapy (3DCRT), field-in-field (FIF), intensity-modulated arc therapy (IMRT), and volumetric modulated arc therapy (VMAT), for breast cancer patients with mastectomy. Our focus was the plan quality and dose distribution to the OARs. Using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist, we performed a systematic review and quality appraisal of primary studies evaluating hybrid therapy to the chest wall and the OARs. An extensive online search of PubMed and Scopus databases was conducted using appropriate keywords. The dose to the OARs (lung, heart, and contralateral breast), planning target volume (PTV), homogeneity index (HI), and conformity index (CI) were extracted. The data were then tabulated and compared for the outcomes between modalities among the studies. Nine studies that met the search criteria were selected to evaluate the PTV coverage and dosimetric results of hybrid and non-hybrid techniques. In terms of 95% PTV coverage, among nine reviewed studies, the largest difference between the two techniques was between VMAT (47.6 Gy) and H-VMAT (48.4 Gy); for the conformity index, the largest difference was noted between 3DCRT (0.58) and H-VMAT (0.79). In both cases, differences were statistically significant ( < 0.005). Two studies showed dose homogeneity improvement within the treatment target in H-VMAT (0.15 and 0.07) compared with 3DCRT (0.41 and 0.12), with a value of <0.001. Two studies did not report on the homogeneity index, and three others observed no statistical difference. Regarding OARs, in the comparison of H-VMAT and VMAT, the largest significant change was in the volume receiving 5 Gy (V) of the ipsilateral lung and the V of the contralateral lung. For the ipsilateral lung, V was 90.7% with VMAT versus 51.45% with H-VMAT. For the contralateral lung, V was 54.9% with VMAT versus 50.5% with H-VMAT. In six studies, the mean dose of the contralateral breast was lower in hybrid techniques than in single modalities: VMAT (4.2%, 6.0%, 1.9%, 7.1%, 4.57%) versus H-VMAT (1.4%, 3.4%, 1.8%, 3.5%, 2.34%) and IMRT (9.1%) versus H-IMRT (4.69%). Although most studies did not report on monitor units and treatment time, those that included them showed that hybrids had lower monitor units and shorter treatment times. Hybrid techniques in radiotherapy, such as combining two modalities, can indeed facilitate lower doses to OARs for patients with a high risk of toxicities. Prospective clinical studies are needed to determine the outcomes of breast cancer treated with hybrid techniques.
PubMed: 38832195
DOI: 10.7759/cureus.59583 -
EClinicalMedicine May 2024Hospital-acquired infections (HAI) are a leading cause of morbidity and mortality globally. These infections are diverse, but the majority are lower respiratory tract...
BACKGROUND
Hospital-acquired infections (HAI) are a leading cause of morbidity and mortality globally. These infections are diverse, but the majority are lower respiratory tract infection (LRTI), surgical site infection (SSI), bloodstream infection (BSI), and urinary tract infection (UTI). For most sub-Saharan African countries, studies revealing the burden and impact of HAI are scarce, and few systematic reviews and meta-analysis have been attempted. We sought to fill this gap by reporting recent trends in HAI in sub-Saharan Africa (SSA) with attention to key patient populations, geographic variation, and associated mortality.
METHODS
Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we conducted a literature search of six electronic databases (Web of Science, Pubmed, APA PsycInfo, CINAHL, Embase, and the Cochrane Library) to identify studies assessing the prevalence of HAI in SSA countries. Studies published between 01 January 2014 and 31 December 2023 were included. We applied no language or publication restrictions. Record screening and data extractions were independently conducted by teams of two or more reviewers. Using the R software (version 4.3.1) meta and metafor packages, we calculated the pooled prevalence estimates from random-effect meta-analysis, and further explored sources of heterogeneity through subgroup analyses and meta-regression. This study is registered with PROSPERO, CRD42023433271.
FINDINGS
Forty-one relevant studies were identified for analysis, consisting of 15 from West Africa (n = 2107), 12 from Southern Africa (n = 2963), 11 from East Africa (n = 2142), and 3 from Central Africa (n = 124). A total of 59.4% of the patient population were associated with paediatric admissions. The pooled prevalence of HAI was estimated at 12.9% (95% CI: 8.9-17.4; n = 7336; number of included estimates [k] = 41, p < 0.001). By subregions, the pooled current prevalence of HAI in the West Africa, Southern Africa, East Africa and Central Africa were estimated at 15.5% (95% CI: 8.3-24.4; n = 2107; k = 15), 6.5% (95% CI: 3.3-10.7; n = 2963; k = 12), 19.7% (95% CI: 10.8-30.5; n = 2142; k = 11) and 10.3% (95% CI: 1.1-27.0; n = 124; k = 3) of the patient populations respectively. We estimated mortality resulting from HAI in SSA at 22.2% (95% CI: 14.2-31.4; n = 1118; k = 9).
INTERPRETATION
Our estimates reveal a high burden of HAI in SSA with significant heterogeneity between regions. Variations in HAI distribution highlight the need for infection prevention and surveillance strategies specifically tailored to enhance prevention and management with special focus on West and East Africa, as part of the broader global control effort.
FUNDING
No funding was received for this study.
PubMed: 38606166
DOI: 10.1016/j.eclinm.2024.102571