The ratio of means method as an alternative to mean differences for analyzing continuous outcome variables in meta-analysis: A simulation study

<p>Abstract</p> <p>Background</p> <p>Meta-analysis of continuous outcomes traditionally uses mean difference (MD) or standardized mean difference (SMD; mean difference in pooled standard deviation (SD) units). We recently used an alternative ratio of mean values (RoM) method, calculating RoM for each study and estimating its variance by the delta method. SMD and RoM allow pooling of outcomes expressed in different units and comparisons of effect sizes across interventions, but RoM interpretation does not require knowledge of the pooled SD, a quantity generally unknown to clinicians.</p> <p>Objectives and methods</p> <p>To evaluate performance characteristics of MD, SMD and RoM using simulated data sets and representative parameters.</p> <p>Results</p> <p>MD was relatively bias-free. SMD exhibited bias (~5%) towards no effect in scenarios with few patients per trial (n = 10). RoM was bias-free except for some scenarios with broad distributions (SD 70% of mean value) and medium-to-large effect sizes (0.5–0.8 pooled SD units), for which bias ranged from -4 to 2% (negative sign denotes bias towards no effect). Coverage was as expected for all effect measures in all scenarios with minimal bias. RoM scenarios with bias towards no effect exceeding 1.5% demonstrated lower coverage of the 95% confidence interval than MD (89–92% vs. 92–94%). Statistical power was similar. Compared to MD, simulated heterogeneity estimates for SMD and RoM were lower in scenarios with bias because of decreased weighting of extreme values. Otherwise, heterogeneity was similar among methods.</p> <p>Conclusion</p> <p>Simulation suggests that RoM exhibits comparable performance characteristics to MD and SMD. Favourable statistical properties and potentially simplified clinical interpretation justify the ratio of means method as an option for pooling continuous outcomes.</p

Risk of dispersion or aerosol generation and infection transmission with nasopharyngeal and oropharyngeal swabs for detection of COVID-19: a systematic review

ObjectivesSARS-CoV-2-related disease, referred to as COVID-19, has emerged as a global pandemic since December 2019. While there is growing recognition regarding possible airborne transmission, particularly in the setting of aerosol-generating procedures and treatments, whether nasopharyngeal and oropharyngeal swabs for SARS-CoV-2 generate aerosols remains unclear.DesignSystematic review.Data sourcesWe searched Ovid MEDLINE and EMBASE up to 3 November 2020. We also searched the China National Knowledge Infrastructure, Chinese Medical Journal Network, medRxiv and ClinicalTrials.gov up to 29 March 2020.Eligibility criteriaAll comparative and non-comparative studies that evaluated dispersion or aerosolisation of viable airborne organisms, or transmission of infection associated with nasopharyngeal or oropharyngeal swab testing.ResultsOf 7702 citations, only one study was deemed eligible. Using a dedicated sampling room with negative pressure isolation room, personal protective equipment including N95 or higher masks, strict sterilisation protocols, structured training with standardised collection methods and a structured collection and delivery system, a tertiary care hospital proved a 0% healthcare worker infection rate among eight nurses conducting over 11 000 nasopharyngeal swabs. No studies examining transmissibility with other safety protocols, nor any studies quantifying the risk of aerosol generation with nasopharyngeal or oropharyngeal swabs for detection of SARS-CoV-2, were identified.ConclusionsThere is limited to no published data regarding aerosol generation and risk of transmission with nasopharyngeal and oropharyngeal swabs for the detection of SARS-CoV-2. Field experiments to quantify this risk are warranted. Vigilance in adhering to current standards for infection control is suggested.</jats:sec

Development of a quality indicator set to measure and improve quality of ICU care in low- and middle-income countries

PURPOSE: To develop a set of actionable quality indicators for critical care suitable for use in low- or middle-income countries (LMICs). METHODS: A list of 84 candidate indicators compiled from a previous literature review and stakeholder recommendations were categorised into three domains (foundation, process, and quality impact). An expert panel (EP) representing stakeholders from critical care and allied specialties in multiple low-, middle-, and high-income countries was convened. In rounds one and two of the Delphi exercise, the EP appraised (Likert scale 1–5) each indicator for validity, feasibility; in round three sensitivity to change, and reliability were additionally appraised. Potential barriers and facilitators to implementation of the quality indicators were also reported in this round. Median score and interquartile range (IQR) were used to determine consensus; indicators with consensus disagreement (median < 4, IQR ≤ 1) were removed, and indicators with consensus agreement (median ≥ 4, IQR ≤ 1) or no consensus were retained. In round four, indicators were prioritised based on their ability to impact cost of care to the provider and recipient, staff well-being, patient safety, and patient-centred outcomes. RESULTS: Seventy-one experts from 30 countries (n = 45, 63%, representing critical care) selected 57 indicators to assess quality of care in intensive care unit (ICU) in LMICs: 16 foundation, 27 process, and 14 quality impact indicators after round three. Round 4 resulted in 14 prioritised indicators. Fifty-seven respondents reported barriers and facilitators, of which electronic registry-embedded data collection was the biggest perceived facilitator to implementation (n = 54/57, 95%) Concerns over burden of data collection (n = 53/57, 93%) and variations in definition (n = 45/57, 79%) were perceived as the greatest barrier to implementation. CONCLUSION: This consensus exercise provides a common set of indicators to support benchmarking and quality improvement programs for critical care populations in LMICs

Early mobilisation in mechanically ventilated patients:A systematic integrative review of definitions and activities

From PubMed via Jisc Publications RouterHistory: received 2018-10-23, accepted 2018-12-11Publication status: epublishMechanically ventilated patients often develop muscle weakness post-intensive care admission. Current evidence suggests that early mobilisation of these patients can be an effective intervention in improving their outcomes. However, what constitutes early mobilisation in mechanically ventilated patients (EM-MV) remains unclear. We aimed to systematically explore the definitions and activity types of EM-MV in the literature. Whittemore and Knafl's framework guided this review. CINAHL, MEDLINE, EMBASE, PsycINFO, ASSIA, and Cochrane Library were searched to capture studies from 2000 to 2018, combined with hand search of grey literature and reference lists of included studies. The Critical Appraisal Skills Programme tools were used to assess the methodological quality of included studies. Data extraction and quality assessment of studies were performed independently by each reviewer before coming together in sub-groups for discussion and agreement. An inductive and data-driven thematic analysis was undertaken on verbatim extracts of EM-MV definitions and activities in included studies. Seventy-six studies were included from which four major themes were inferred: (1) , (2) , (3) and (4) . The first theme indicates that EM-MV is either not fully defined in studies or when a definition is provided this is not standardised across studies. The remaining themes reflect the diversity of EM-MV activities which depends on patients' characteristics and ICU settings; the negotiated decision-making process between patients and staff; and their interdependent relationship during the implementation. This review highlights the absence of an agreed definition and on what constitutes early mobilisation in mechanically ventilated patients. To advance research and practice an agreed and shared definition is a pre-requisite

The evolution of intensive care unit performance assessment

Intensive care units (ICUs) share the problems experienced by the health care system at large. Various approaches to define and manage the quality of care patients receive in the ICU have been proposed. Performance measurement involves the collection of data to evaluate an ICU's performance against itself (over time), other ICUs, or other appropriate benchmarks. Successful performance assessment requires the quantification of relevant indexes of performance. Although these indexes are increasingly being developed, it will be some time before widely recognized, validated systems are available.</p

Effect of prone positioning in patients with acute respiratory distress syndrome and high Simplified Acute Physiology Score II

Characterization of a new clinically more interpretable techniques to pool continuous outcomes in meta-analysis.Canadian Institutes of Health ResearchClinician Scientist - Phase