A guide to prospective meta-analysis

Development of the individual participant data integrity tool for assessing the integrity of randomised trials using individual participant data

Increasing integrity concerns in medical research have prompted the development of tools to detect untrustworthy studies. Existing tools primarily assess published aggregate data (AD), though scrutiny of individual participant data (IPD) is often required to detect trustworthiness issues. Thus, we developed the IPD Integrity Tool for detecting integrity issues in randomised trials with IPD available. This manuscript describes the development of this tool. We conducted a literature review to collate and map existing integrity items. These were discussed with an expert advisory group; agreed items were included in a standardised tool and automated where possible. We piloted this tool in two IPD meta-analyses (including 116 trials) and conducted preliminary validation checks on 13 datasets with and without known integrity issues. We identified 120 integrity items: 54 could be conducted using AD, 48 required IPD, and 18 were possible with AD, but more comprehensive with IPD. An initial reduced tool was developed through consensus involving 13 advisors, featuring 11 AD items across four domains, and 12 IPD items across eight domains. The tool was iteratively refined throughout piloting and validation. All studies with known integrity issues were accurately identified during validation. The final tool includes seven AD domains with 13 items and eight IPD domains with 18 items. The quality of evidence informing healthcare relies on trustworthy data. We describe the development of a tool to enable researchers, editors, and others to detect integrity issues using IPD. Detailed instructions for its application are published as a complementary manuscript in this issue.

Initial Oxygen Concentration for the Resuscitation of Infants Born at Less Than 32 Weeks' Gestation: A Systematic Review and Individual Participant Data Network Meta-Analysis

Importance

Resuscitation with lower fractional inspired oxygen (FiO2) reduces mortality in term and near-term infants but the impact of this practice on very preterm infants is unclear.

Objective

To evaluate the relative effectiveness of initial FiO2 on reducing mortality, severe morbidities, and oxygen saturations (SpO2) in preterm infants born at less than 32 weeks' gestation using network meta-analysis (NMA) of individual participant data (IPD).

Data Sources

MEDLINE, Embase, CENTRAL, CINAHL, ClinicalTrials.gov, and WHO ICTRP from 1980 to October 10, 2023.

Study Selection

Eligible studies were randomized clinical trials enrolling infants born at less than 32 weeks' gestation comparing at least 2 initial oxygen concentrations for delivery room resuscitation, defined as either low (≤0.3), intermediate (0.5-0.65), or high (≥0.90) FiO2.

Data Extraction and Synthesis

Investigators from eligible studies were invited to provide IPD. Data were processed and checked for quality and integrity. One-stage contrast-based bayesian IPD-NMA was performed with noninformative priors and random effects and adjusted for key covariates.

Main Outcomes and Measures

The primary outcome was all-cause mortality at hospital discharge. Secondary outcomes were morbidities of prematurity and SpO2 at 5 minutes.

Results

IPD were provided for 1055 infants from 12 of the 13 eligible studies (2005-2019). Resuscitation with high (≥0.90) initial FiO2 was associated with significantly reduced mortality compared to low (≤0.3) (odds ratio [OR], 0.45; 95% credible interval [CrI], 0.23-0.86; low certainty) and intermediate (0.5-0.65) FiO2 (OR, 0.34; 95% CrI, 0.11-0.99; very low certainty). High initial FiO2 had a 97% probability of ranking first to reduce mortality. The effects on other morbidities were inconclusive.

Conclusions and Relevance

High initial FiO2 (≥0.90) may be associated with reduced mortality in preterm infants born at less than 32 weeks' gestation compared to low initial FiO2 (low certainty). High initial FiO2 is possibly associated with reduced mortality compared to intermediate initial FiO2 (very low certainty) but more evidence is required.

Protocol for a systematic review with prospective individual patient data meta-analysis in EGFR-mutant NSCLC with brain metastases to assess the effect of SRS+osimertinib compared to osimertinib alone: the STARLET Collaboration

BACKGROUND

Patients with advanced non-small-cell lung cancer (NSCLC) with activating mutations in the epidermal growth factor receptor (EGFR) gene are a heterogeneous population who often develop brain metastases (BM). The optimal management of patients with asymptomatic brain metastases is unclear given the activity of newer-generation targeted therapies in the central nervous system. We present a protocol for an individual patient data (IPD) prospective meta-analysis to evaluate whether the addition of stereotactic radiosurgery (SRS) before osimertinib treatment will lead to better control of intracranial metastatic disease. This is a clinically relevant question that will inform practice.

METHODS

Randomised controlled trials will be eligible if they include participants with BM arising from EGFR-mutant NSCLC and suitable to receive osimertinib both in the first-line and second-line settings (P); comparisons of SRS followed by osimertinib versus osimertinib alone (I, C) and intracranial disease control included as an endpoint (O). Systematic searches of Medline (Ovid), Embase (Ovid), Cochrane Central Register of Controlled Trials (CENTRAL), CINAHL (EBSCO), PsychInfo, ClinicalTrials.gov and the WHO's International Clinical Trials Registry Platform's Search Portal will be undertaken. An IPD meta-analysis will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome is intracranial progression-free survival, as determined by response assessment in neuro-oncology-BM criteria. Secondary outcomes include overall survival, time to whole brain radiotherapy, quality of life, and adverse events of special interest. Effect differences will be explored among prespecified subgroups.

ETHICS AND DISSEMINATION

Approved by each trial's ethics committee. Results will be relevant to clinicians, researchers, policymakers and patients, and will be disseminated via publications, presentations and media releases.

PROSPERO REGISTRATION

CRD42022330532.

Air or Oxygen for Infant Resuscitation: A Prospective Cohort Study of Moderate-Late Preterm Infants Requiring Delivery Room Resuscitation

INTRODUCTION

Due to concerns of oxidative stress and injury, most clinicians currently use lower levels of fractional inspired oxygen (FiO2, 0.21-0.3) to initiate respiratory support for moderate to late preterm (MLPT, 32-36 weeks gestation) infants at birth. Whether this practice achieves recommended oxygen saturation (SpO2) targets is unknown.

METHODS

We aimed to determine SpO2 trajectories of MLPT infants requiring respiratory support at birth. We conducted a prospective, opportunistic, observational study with consent waiver. Preductal SpO2 readings were obtained during the first 10 min of life from infants between 32 and 36 weeks gestation requiring respiratory support in the delivery room. Primary outcome was reaching a minimum SpO2 80% at 5 min of life. The study was prospectively registered (ACTRN12620001252909).

RESULTS

A total of 76 eligible infants were recruited between February 2021 and March 2022 from 5 hospitals in Australia. Most (n = 58, 76%) had respiratory support initiated with FiO2 0.21 (range 0.21-1.0) using CPAP (92%). Median SpO2 at 5 min was 81% (interquartile range [IQR] 67-90) and 93% (IQR 86-96) at 10 min. At 5 min, 18/43 (42%) infants had SpO2 below 80% and only 8/43 (19%) reached SpO2 80-85%.

CONCLUSIONS

Many MLPT infants requiring respiratory support do not achieve recommended SpO2 targets. In very preterm infants, SpO2 <80% at 5 min of life increases risk of death, intraventricular haemorrhage, and neurodevelopmental impairment. The implications on this practice on the health outcomes of MLPT infants are unclear and require further research.

Systematic reviews and meta-analyses in regional anesthesia and pain medicine (Part II): guidelines for performing the systematic review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia.

Statistical primer: individual patient data meta-analysis and meta-analytic approaches in case of non-proportional hazards

Individual patient data (IPD) meta-analyses build upon traditional (aggregate data) meta-analyses by collecting IPD from the individual studies rather than using aggregated summary data. Although both traditional and IPD meta-analyses produce a summary effect estimate, IPD meta-analyses allow for the analysis of data to be performed as a single dataset. This allows for standardization of exposure, outcomes, and analytic methods across individual studies. IPD meta-analyses also allow the utilization of statistical methods typically used in cohort studies, such as multivariable regression, survival analysis, propensity score matching, uniform subgroup and sensitivity analyses, better management of missing data, and incorporation of unpublished data. However, they are more time-intensive, costly, and subject to participation bias. A separate issue relates to the meta-analytic challenges when the proportional hazards assumption is violated. In these instances, alternative methods of reporting time-to-event estimates, such as restricted mean survival time should be used. This statistical primer summarizes key concepts in both scenarios and provides pertinent examples.

A collaborative network trial to evaluate the effectiveness of implementation strategies to maximize adoption of a school-based healthy lunchbox program: a study protocol

Introduction

An important impediment to the large-scale adoption of evidence-based school nutrition interventions is the lack of evidence on effective strategies to implement them. This paper describes the protocol for a "Collaborative Network Trial" to support the simultaneous testing of different strategies undertaken by New South Wales Local Health Districts to facilitate the adoption of an effective school-based healthy lunchbox program ('SWAP IT'). The primary objective of this study is to assess the effectiveness of different implementation strategies to increase school adoption of the SWAP across New South Wales Local Health Districts.

Methods

Within a Master Protocol framework, a collaborative network trial will be undertaken. Independent randomized controlled trials to test implementation strategies to increase school adoption of SWAP IT within primary schools in 10 different New South Wales Local Health Districts will occur. Schools will be randomly allocated to either the intervention or control condition. Schools allocated to the intervention group will receive a combination of implementation strategies. Across the 10 participating Local Health Districts, six broad strategies were developed and combinations of these strategies will be executed over a 6 month period. In six districts an active comparison group (containing one or more implementation strategies) was selected. The primary outcome of the trial will be adoption of SWAP IT, assessed via electronic registration records captured automatically following online school registration to the program. The primary outcome will be assessed using logistic regression analyses for each trial. Individual participant data component network meta-analysis, under a Bayesian framework, will be used to explore strategy-covariate interactions; to model additive main effects (separate effects for each component of an implementation strategy); two way interactions (synergistic/antagonistic effects of components), and full interactions.

Discussion

The study will provide rigorous evidence of the effects of a variety of implementation strategies, employed in different contexts, on the adoption of a school-based healthy lunchbox program at scale. Importantly, it will also provide evidence as to whether health service-centered, collaborative research models can rapidly generate new knowledge and yield health service improvements.

Clinical trial registration

This trial is registered prospectively with the Australian New Zealand Clinical Trials Registry (ACTRN12623000558628).

Dexamethasone doses in patients with COVID-19 and hypoxia: A systematic review and meta-analysis

BACKGROUND

The optimal dose of dexamethasone for severe/critical COVID-19 is uncertain. We compared higher versus standard doses of dexamethasone in adults with COVID-19 and hypoxia.

METHODS

We searched PubMed and trial registers until 23 June 2023 for randomised clinical trials comparing higher (>6 mg) versus standard doses (6 mg) of dexamethasone in adults with COVID-19 and hypoxia. The primary outcome was mortality at 1 month. Secondary outcomes were mortality closest to 90 days; days alive without life support; and the occurrence of serious adverse events/reactions (SAEs/SARs) closest to 1 month. We assessed the risk of bias using the Cochrane RoB2 tool, risk of random errors using trial sequential analysis, and certainty of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

We included eight trials (2478 participants), of which four (1293 participants) had low risk of bias. Higher doses of dexamethasone probably resulted in little to no difference in mortality at 1 month (relative risk [RR] 0.97, 95% CI: 0.79-1.19), mortality closest to Day 90 (RR 1.01, 95% CI: 0.86-1.20), and SAEs/SARs (RR 1.00, 95% CI: 0.97-1.02). Higher doses of dexamethasone probably increased the number of days alive without invasive mechanical ventilation and circulatory support but had no effect on days alive without renal replacement therapy.

CONCLUSIONS

Based on low to moderate certainty evidence, higher versus standard doses of dexamethasone probably result in little to no difference in mortality, SAEs/SARs, and days alive without renal replacement therapy, but probably increase the number of days alive without invasive mechanical ventilation and circulatory support.

Systematic Reviews and Meta-analyses in Regional Anesthesia and Pain Medicine (Part II): Guidelines for Performing the Systematic Review

In Part I of this series, we provide guidance for preparing a systematic review protocol. In this article, we highlight important steps and supplement with exemplars on conducting and reporting the results of a systematic review. We suggest how authors can manage protocol violations, multiplicity of outcomes and analyses, and heterogeneity. The quality (certainty) of the evidence and strength of recommendations should follow the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) approach. It is our goal that Part II of this series provides valid guidance to authors and peer reviewers who conduct systematic reviews to adhere to important constructs of transparency, structure, reproducibility, and accountability. This will likely result in more rigorous systematic reviews being submitted for publication to the journals like Regional Anesthesia & Pain Medicine and Anesthesia & Analgesia .

Effectiveness of full Pulpotomy compared with Root canal treatment in managing teeth with signs and symptOms indicative of irreversible pulpitis: a protocol for prospectiVE meta-analysis of individual participant data of linked randomised clinical trials (PROVE)

BACKGROUND

Full pulpotomy has been proposed as an alternative to root canal treatment in teeth with signs and symptoms indicative of irreversible pulpitis (IRP), but the evidence is limited, relying on underpowered studies with a high risk of bias. The aim of this study is to conduct a prospective meta-analysis (PMA) of individual participant data of a series of individual randomised trials to provide robust evidence on the clinical and cost-effectiveness of pulpotomy compared with root canal treatment.

METHODS

Individual participant data will be obtained from a series of randomised trials designed and conducted by a consortium of multi-national investigators with an interest in vital pulp treatment. These individualised trials will be conducted using a specified protocol, defined outcomes, and outcome measures. Ten parallel-group randomised trials currently being conducted in 10 countries will provide data from more than 500 participants. The primary outcome is a composite measure defined as (1) the absence of pain indicative of IRP, (2) the absence of signs and symptoms indicative of acute or chronic apical periodontitis, and (3) the absence of radiographic evidence of failure including radiolucency or resorption. Individual participant data will be obtained, assessed, and checked for quality by two independent reviewers prior to the PMA. Pooled estimates on treatment effects will be generated using a 2-stage meta-analysis approach. The first stage involves a standard regression analysis in each trial to produce aggregate data on treatment effect estimates followed by an inverse variance weighted meta-analysis to combine these aggregate data and produce summary statistics and forest plots. Cost-effectiveness analysis based on the composite outcome will be undertaken as a process evaluation to evaluate treatment fidelity and acceptability by patients and dentists.

RESULTS

The research question and trial protocol were developed and approved by investigators in all 10 sites. All sites use shared resources including study protocols, data collection forms, participant information leaflets, and consent forms in order to improve flow, consistency, and reproducibility. Each site obtained its own Institutional Review Board approval, and trials were registered in appropriate open access platforms. Patient recruitment has started in most sites, as of July 2023.

DISCUSSION

PMA offers a rigorous, flexible, and efficient methodology to answer this important research question and provide results with improved generalisability and external validity compared with traditional trials and retrospective meta-analyses. The results of this study will have implications for both the delivery of clinical practice and structured clinical guidelines' development.

TRIAL REGISTRATION

PROSPERO CRD42023446809. Registered on 08 February 2023.

A Primer on Systematic Review and Meta-analysis in Diabetes Research

A systematic review is a rigorous process that involves identifying, selecting, and synthesizing available evidence pertaining to an a priori-defined research question. The resulting evidence base may be summarized qualitatively or through a quantitative analytic approach known as meta-analysis. Systematic review and meta-analysis (SRMAs) have risen in popularity across the scientific realm including diabetes research. Although well-conducted SRMAs are an indispensable tool in informing evidence-based medicine, the proliferation of SRMAs has led to many reviews of questionable quality and misleading conclusions. The objective of this article is to provide up-to-date knowledge and a comprehensive understanding of strengths and limitations of SRMAs. We first provide an overview of the SRMA process and offer ways to identify common pitfalls at key steps. We then describe best practices as well as evolving approaches to mitigate biases, improve transparency, and enhance rigor. We discuss several recent developments in SRMAs including individual-level meta-analyses, network meta-analyses, umbrella reviews, and prospective meta-analyses. Additionally, we outline several strategies that can be used to enhance quality of SRMAs and present key questions that authors, editors, and readers should consider in preparing or critically reviewing SRMAs.

Incentive spirometry is an effective strategy to improve the quality of postoperative care in patients

Postoperative pulmonary complications (PPCs) most commonly occur after thoracic surgery. Not only prolonged hospital stay and increased financial expenses but also morbidity and even mortality may be troublesome for those with PPCs. Herein, we aimed to conduct a comprehensive systematic review and meta-analysis of available data to examine the effectiveness of incentive spirometry (IS) to reduce PPCs and shorten hospital stay. This systematic review and meta-analysis included 5 randomized controlled trials (RCT) and 3 retrospective cohort study (10,322 patients in total) in PubMed, Embase and Cochrane Library until September 31, 2021. We assessed the clinical efficacy of IS using length of hospital stay, PPCs, postoperative pneumonia, and postoperative atelectasis with meta-analysis, meta-regression and trial sequential analysis (TSA). With this meta-analysis, the length of hospital stay in patients undergoing IS was significantly shorter (1.8 days) than that in patients not receiving IS (MD = -1.80, 95% CI = -2.95 to -0.65). Patients undergoing IS also had reduced risk of PPCs (32%) and postoperative pneumonia (17.9%) with statistical significance than patients not undergoing IS (PPC: OR = 0.68, 95% CI = 0.51-0.90) (Pneumonia: OR = 0.821, 95% CI = 0.677-0.995).In meta-regression, the benefits of undergoing IS in patients with preoperative predicted FEV1 of <80% in a linear fashion with decreasing PPCs. IS is an effective modality to improve the quality of postoperative care for patients after pulmonary resection, compared with the control group without using IS; and applying IS has favorable outcomes of shorter length of hospital stay (1.8 days) and lower occurrence of PPCs (32% of risk reduction), which are conclusive and robust based on our validation via TSA. Moreover, the IS device is more beneficial for patients with preoperative predicted FEV1 of <80% than that in others.

Effects of the Informed Health Choices secondary school intervention: A prospective meta-analysis

AIM

The aim of this prospective meta-analysis was to synthesize the results of three cluster-randomized trials of an intervention designed to teach lower-secondary school students (age 14-16) to think critically about health choices.

METHODS

We conducted the trials in Kenya, Rwanda, and Uganda. The intervention included a 2- to 3-day teacher training workshop, digital resources, and ten 40-min lessons. The lessons focused on nine key concepts. We did not intervene in control schools. The primary outcome was a passing score on a test (≥9 of 18 multiple-choice questions answered correctly). We performed random effects meta-analyses to estimate the overall adjusted odds ratios. Secondary outcomes included effects of the intervention on teachers.

RESULTS

Altogether, 244 schools (11,344 students) took part in the three trials. The overall adjusted odds ratio was 5.5 (95% CI: 3.0-10.2; p < 0.0001) in favor of the intervention (high certainty evidence). This corresponds to 33% (95% CI: 25-40%) more students in the intervention schools passing the test. Overall, 3397 (58%) of 5846 students in intervention schools had a passing score. The overall adjusted odds ratio for teachers was 13.7(95% CI: 4.6-40.4; p < 0.0001), corresponding to 32% (95% CI: 6%-57%) more teachers in the intervention schools passing the test (moderate certainty evidence). Overall, 118 (97%) of 122 teachers in intervention schools had a passing score.

CONCLUSIONS

The intervention led to a large improvement in the ability of students and teachers to think critically about health choices, but 42% of students in the intervention schools did not achieve a passing score.

Individualized lifestyle intervention in PCOS women (IPOS): a study protocol for a multicentric randomized controlled trial for evaluating the effectiveness of an individualized lifestyle intervention in PCOS women who wish to conceive

BACKGROUND

Polycystic ovary syndrome (PCOS) is a common endocrine condition which affects women in the reproductive age group. South Asian women with PCOS have a higher risk of insulin resistance and metabolic disorder compared to women from other ethnic backgrounds. Lifestyle interventions such as dietary advice and physical exercise are recommended as a first-line management option for infertile women with PCOS. Most of the randomized controlled trials evaluating the role of lifestyle interventions in infertile PCOS women were characterized by methodological issues. The uptake of lifestyle modifications as a treatment strategy in the South Asian population is complicated by a difficult-to-change conventional high-carbohydrate diet and limited availability of space for physical activity in the region.

METHODS

The study is designed as an open-label, multicentre, randomized controlled trial in South Asian women with PCOS. Women attending the fertility clinic will be screened for eligibility, and women aged between 19 and 37 years who have been diagnosed with PCOS and wishing to conceive will be invited to participate in the trial. We will include women with body mass index (BMI) between ≥ 23 and ≤ 35 kg/m² and duration of infertility ≤ 3 years. We plan to randomize women with PCOS into two groups: group A will receive the intervention which will consist of individualized advice on diet and physical exercise along with a telephonic reminder system and follow-up visits, and group B (control) will receive one-time advice on diet and physical exercise. Both groups will receive up to three cycles of ovulation induction with letrozole after 3 months of randomization during the 6-month treatment period. The primary outcome of the trial will be the live birth following conception during the intervention period. The secondary outcomes include clinical pregnancy rate, ongoing pregnancy rate, miscarriage rate, ectopic pregnancy rate, stillbirth, time to pregnancy, mean weight loss, differences in anthropometric parameters, improvement in menstrual regularity and quality of life score.

DISCUSSION

The IPOS trial results could help clarify and provide more robust evidence for advocating an individualized lifestyle intervention in PCOS women who wish to conceive.

TRIAL REGISTRATION

Clinical Trial Registry of India CTRI/2023/04/051620. Registered on 13 April 2023.

Child and adolescent obesity

The prevalence of child and adolescent obesity has plateaued at high levels in most high-income countries and is increasing in many low-income and middle-income countries. Obesity arises when a mix of genetic and epigenetic factors, behavioural risk patterns and broader environmental and sociocultural influences affect the two body weight regulation systems: energy homeostasis, including leptin and gastrointestinal tract signals, operating predominantly at an unconscious level, and cognitive-emotional control that is regulated by higher brain centres, operating at a conscious level. Health-related quality of life is reduced in those with obesity. Comorbidities of obesity, including type 2 diabetes mellitus, fatty liver disease and depression, are more likely in adolescents and in those with severe obesity. Treatment incorporates a respectful, stigma-free and family-based approach involving multiple components, and addresses dietary, physical activity, sedentary and sleep behaviours. In adolescents in particular, adjunctive therapies can be valuable, such as more intensive dietary therapies, pharmacotherapy and bariatric surgery. Prevention of obesity requires a whole-system approach and joined-up policy initiatives across government departments. Development and implementation of interventions to prevent paediatric obesity in children should focus on interventions that are feasible, effective and likely to reduce gaps in health inequalities.

Optimizing cord management for each preterm baby - Challenges of collating individual participant data and recommendations for future collaborative research

The optimal cord management strategy at birth for each preterm baby is still unknown, despite more than 100 randomized controlled trials (RCTs) undertaken on this question. To address this, we brought together all RCTs examining cord management strategies at preterm birth in the iCOMP (individual participant data on COrd Management at Preterm birth) Collaboration, to perform an individual participant data network meta-analysis. In this paper, we describe the trials and tribulations around obtaining individual participant data to resolve controversies around cord clamping, and we derive key recommendations for future collaborative research in perinatology. To reliably answer outstanding questions, future cord management research needs to be collaborative and coordinated, by aligning core protocol elements, ensuring quality and reporting standards are met, and carefully considering and reporting on vulnerable sub-populations. The iCOMP Collaboration is an example of the power of collaboration to address priority research questions, and ultimately improve neonatal outcomes worldwide.

A Bayesian model for combining standardized mean differences and odds ratios in the same meta-analysis

In meta-analysis practice, researchers frequently face studies that report the same outcome differently, such as a continuous variable (e.g., scores for rating depression) or a binary variable (e.g., counts of patients with depression dichotomized by certain latent and unreported depression scores). For combining these two types of studies in the same analysis, a simple conversion method has been widely used to handle standardized mean differences (SMDs) and odds ratios (ORs). This conventional method uses a linear function connecting the SMD and log OR; it assumes logistic distributions for (latent) continuous measures. However, the normality assumption is more commonly used for continuous measures, and the conventional method may be inaccurate when effect sizes are large or cutoff values for dichotomizing binary events are extreme (leading to rare events). This article proposes a Bayesian hierarchical model to synthesize SMDs and ORs without using the conventional conversion method. This model assumes exact likelihoods for continuous and binary outcome measures, which account for full uncertainties in the synthesized results. We performed simulation studies to compare the performance of the conventional and Bayesian methods in various settings. The Bayesian method generally produced less biased results with smaller mean squared errors and higher coverage probabilities than the conventional method in most cases. Nevertheless, this superior performance depended on the normality assumption for continuous measures; the Bayesian method could lead to nonignorable biases for non-normal data. In addition, we used two case studies to illustrate the proposed Bayesian method in real-world settings.

PROspective Meta-analysis Of Trials of Initial Oxygen in preterm Newborns (PROMOTION): Protocol for a systematic review and prospective meta-analysis with individual participant data on initial oxygen concentration for resuscitation of preterm infants

BACKGROUND

Clinicians favour low oxygen concentrations when resuscitating preterm infants immediately after birth despite inconclusive evidence to support this practice. Prospective meta-analysis (PMA) is a novel approach where studies are identified as eligible for inclusion in the meta-analysis before their results are known.

AIMS

To explore whether high (60%) or low (30%) oxygen is associated with greater efficacy and safety for the initial resuscitation (immediately after birth) of preterm infants born at <29 weeks' gestation.

METHODS

We will conduct a prospective meta-analysis (PMA) with individual participant data (IPD). We will perform a systematic search to identify ongoing RCTs including infants <29 weeks' gestation randomised to high (60%) or low (30%) oxygen for initial resuscitation after birth. IPD will be sought for all infants randomised for the purpose of meta-analysis. We will employ a one-stage random-effects approach to IPD meta-analysis. Potential heterogeneity and the differential effect of high or low oxygen will be explored through subgroup and interaction analyses. The primary outcome of this study is all-cause mortality prior to hospital discharge. There will be a follow-up analysis of neurodevelopmental outcomes once available.

RESULTS/CONCLUSION

The results of neonatal outcomes at hospital discharge are expected by 2025, and neurodevelopmental outcomes by 2027.

Harmonization of maternal balanced energy-protein supplementation studies for individual participant data (IPD) meta-analyses - finding and creating similarities in variables and data collection

BACKGROUND

Public health and clinical recommendations are established from systematic reviews and retrospective meta-analyses combining effect sizes, traditionally, from aggregate data and more recently, using individual participant data (IPD) of published studies. However, trials often have outcomes and other meta-data that are not defined and collected in a standardized way, making meta-analysis problematic. IPD meta-analysis can only partially fix the limitations of traditional, retrospective, aggregate meta-analysis; prospective meta-analysis further reduces the problems.

METHODS

We developed an initiative including seven clinical intervention studies of balanced energy-protein (BEP) supplementation during pregnancy and/or lactation that are being conducted (or recently concluded) in Burkina Faso, Ethiopia, India, Nepal, and Pakistan to test the effect of BEP on infant and maternal outcomes. These studies were commissioned after an expert consultation that designed recommendations for a BEP product for use among pregnant and lactating women in low- and middle-income countries. The initiative goal is to harmonize variables across studies to facilitate IPD meta-analyses on closely aligned data, commonly called prospective meta-analysis. Our objective here is to describe the process of harmonizing variable definitions and prioritizing research questions. A two-day workshop of investigators, content experts, and advisors was held in February 2020 and harmonization activities continued thereafter. Efforts included a range of activities from examining protocols and data collection plans to discussing best practices within field constraints. Prior to harmonization, there were many similar outcomes and variables across studies, such as newborn anthropometry, gestational age, and stillbirth, however, definitions and protocols differed. As well, some measurements were being conducted in several but not all studies, such as food insecurity. Through the harmonization process, we came to consensus on important shared variables, particularly outcomes, added new measurements, and improved protocols across studies.

DISCUSSION

We have fostered extensive communication between investigators from different studies, and importantly, created a large set of harmonized variable definitions within a prospective meta-analysis framework. We expect this initiative will improve reporting within each study in addition to providing opportunities for a series of IPD meta-analyses.

Role of factor VIII, IX, and XI in venous thrombosis recurrence risk in adults and children: A systematic review

Background

Predicting recurrent venous thromboembolic events (VTEs) is challenging in clinical practice for both adults and children, but it is relevant for clinical management. Identifying laboratory risk factors for VTE recurrence may aid in clinical decision-making.

Objective

The goal of this systematic review is to investigate the predictive role of FVIII, IX, or XI in recurrent VTE in adult and pediatric patients with a first VTE.

Methods

A systematic review of the published literature was conducted in databases MEDLINE In-Process, Other Nonindexed Citations, MEDLINE Epub Ahead of Print, EMBASE Classic + EMBASE (OvidSP), and Cochrane (Wiley). We included observational and interventional studies that comprised adults or children with a first VTE, FVIII, FIX, and/or FXI and objectively confirmed VTE recurrence. The quality in prognosis studies tool was used to assess the risk of bias.

Results

We identified 2177 unique studies, of which 19 were included (18 for adults and 1 for children). The risk of bias was overall low to moderate. The studies were heterogenous with regards to population (provoked/unprovoked primary VTE), exposure (type of assay and cut-off values), and statistical analysis results (measures of association and modeling strategy). In adults, contradictory evidence was found for FVIII and FXI as outcome predictors, while no research could establish if FIX predicts VTE recurrence. Data in pediatrics were limited. Given the extensive heterogeneity of the literature, a meta-analysis was not performed.

Conclusions

Overall, there is contradictory evidence that FVIII, FIX, or FXI predict recurrent VTE in adults and children. Addressing heterogeneity is a relevant aspect to consider in future studies investigating prognostic factors for VTE recurrence.

Registration of health and medical research

Registration of health and medical research is an effective way of improving the transparency and credibility of evidence. Registration involves pre-specifying the research objectives, design, methods and analytic plan on a publicly accessible repository before conducting the study. Registration can reduce bias and improve the transparency and credibility of research findings. Registration is mandated for clinical trials, but it is also relevant to systematic reviews, observational and preclinical experimental research. This paper describes how researchers can register their research and outlines possible barriers and challenges in doing so. Widespread adoption of research registration can reduce research waste and improve evidence-informed clinical and policy decision making.

The power of integrating data: advancing pain research using meta-analysis

Publications related to pain research have increased significantly in recent years. The abundance of new evidence creates challenges staying up to date with the latest information. A comprehensive understanding of the literature is important for both clinicians and investigators involved in pain research. One commonly used method to combine and analyse data in health care research is meta-analysis. The primary aim of a meta-analysis is to quantitatively synthesise the results of multiple studies focused on the same research question. Meta-analysis is a powerful tool that can be used to advance pain research. However, there are inherent challenges when combining data from multiple sources. There are also numerous models and statistical considerations when undertaking a meta-analysis. This review aims to discuss the planning and preparation for completing a meta-analysis, review commonly used meta-analysis models, and evaluate the clinical implications of meta-analysis in pain research.

Clinical outcomes in the surgical management of ankle fractures: A systematic review and meta-analysis of fibular intramedullary nail fixation vs. open reduction and internal fixation in randomized controlled trials

BACKGROUND

What level I evidence exists to support the use of FNF for surgical management of ankle fractures in high risk patients? The purpose of this study was to compare clinical outcomes following fibular intramedullary nail fixation (FNF) and open reduction and internal fixation (ORIF) of ankle fractures.

METHODS

A systematic review of the current literature was performed according to Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) guidelines. Certainty of evidence reported according to GRADE (Grading of Recommendations Assessment, Development, and Evaluation). Our primary hypothesis was that patients undergoing FNF procedures to manage an ankle fracture would have significantly higher patient reported outcome scores (PROs) than patients undergoing ORIF. Primary study outcome measures were validated PROs. Secondary outcome measures included complication rate, secondary surgery rate, and bony union.

RESULTS

The primary outcome analysis revealed no evidence of a significant effect difference on Olerud and Molander Ankle Score (OMAS) PRO and no evidence of statistical heterogeneity. Secondary outcome analysis revealed a significant 0.30 (0.12-0.74 95CI) relative risk reduction for complications in FNF (P = 0.008). No evidence of an effect difference for bony union. The GRADE certainty of the evidence was rated as low for bone union. No evidence of reporting bias was appreciated. Sensitivity analyses did not significantly alter effect estimates.

CONCLUSION

This systematic review and meta-analysis restricted to evidence derived from RCTs revealed that the quality of evidence is reasonably strong and likely sufficient to conclude: (1) there is likely no clinically important difference between FNF and ORIF up to 12 months post-operatively, as defined by OMS (moderate certainty); (2) surgeons may reasonably expect reduced complications in 14 out of every 100 patients treated with FNF (moderate certainty); (3) there is likely no difference in bony union (low certainty). Future studies should investigate more patient-centered outcomes and if short-term findings are durable over time if these findings apply to lower risk populations.

LEVEL OF EVIDENCE

Systematic review and meta-analysis of level I evidence.

Vibration of effect in more than 16 000 pooled analyses of individual participant data from 12 randomised controlled trials comparing canagliflozin and placebo for type 2 diabetes mellitus: multiverse analysis

Objective

To evaluate the impact of conducting all possible pooled analyses across different combinations of randomised controlled trials and endpoints.

Design

Multiverse analysis, consisting of numerous pooled analyses of individual participant data.

Setting

Individual patient data from 12 randomised controlled trials comparing canagliflozin treatment with placebo, shared on the Yale University Open Data Access project (https://yoda.yale.edu/) platform, up to 16 April 2021.

Participants

15 094 people with type 2 diabetes mellitus.

Main outcome measures

Pooled analyses estimated changes in serum glycated haemoglobin (HbA1c), major adverse cardiovascular events, and serious adverse events at weeks 12, 18, 26, and 52. The distribution of effect estimates was calculated for all possible combinations, and the direction and magnitude of the first and 99th centiles of effect estimates were compared.

Results

Across 16 332 distinct pooled analyses comparing canagliflozin with placebo for changes in HbA1c, standardised effect estimates were in favour of canagliflozin treatment at both the first centile (-0.75%) and 99th centile (-0.48%); 15 994 (97.93%) analyses showed significant results (P<0.05) in favour of canagliflozin. For major adverse cardiovascular events, estimated hazard ratios were 0.20 at the first centile and 0.90 at the 99th centile; 2705 of 8144 analyses (33.21%) were significant, all of which were in favour of canagliflozin treatment. For serious adverse events, estimated hazard ratios were 0.59 at the first centile and 1.14 at the 99th centile; 5793 of 16 332 (35.47%) analyses were significant, with 5754 in favour of canagliflozin and 39 in favour of placebo.

Conclusion

Results from pooled analyses can be subject to vibration of effects and should be critically appraised, especially regarding the risk for selection and availability bias in individual participant data retrieved.

Examining the sustainability of effects of early childhood obesity prevention interventions: Follow-up of the EPOCH individual participant data prospective meta-analysis

BACKGROUND

Although early childhood obesity prevention has become an important issue internationally, little evidence exists regarding longer term effects (i.e., sustainability) of early interventions.

OBJECTIVE

To determine whether intervention benefits at 2 years of age were sustained at 3.5 and 5 years.

METHODS

Follow-up of the Early Prevention of Obesity in Children (EPOCH) individual participant data prospective meta-analysis of four randomized controlled trials including 2196 mother-child dyads at baseline. Interventions were home- or community-based, commenced within 6 months of birth, ended by 2 years of age, and comprised multiple sessions. Controls received standard care. BMI z-score (primary outcome), other anthropometric measures and weight-related behaviours were initially measured at 1.5-2 years and followed up at 3.5 and 5 years.

RESULTS

Positive intervention effects on BMI z-scores at 1.5-2 years of age were not apparent by 3.5 years (-0.04 adjusted mean difference; 95% CI:-0.14, 0.06; p = 0.424), and 5 years (0.03; 95% CI: -0.08, 0.14; p = 0.60). While prolonged intervention benefits were detected for a few, but not the majority of, weight-related behaviours at 3.5 years, these effects diminished over time.

CONCLUSION

This meta-analysis found that initial positive effects of childhood obesity interventions faded out after interventions ended, pointing toward the importance of a suite of interventions implemented at multiple stages across childhood.

Association between exposures to phthalate metabolites and preterm birth and spontaneous preterm birth: A systematic review and meta-analysis

Emerging evidence from observational studies proves the association between preterm birth (PTB) and phthalate metabolites; however, such findings are inconsistent and inconclusive. This meta-analysis aimed to clarify this association by accessing the connection between 11 phthalate metabolites and PTB, and 6 phthalate metabolites and spontaneous PTB. The PubMed, Embase, and WOS (Web of Science) databases were searched up to July 2020. Seven prospective studies met the inclusion criteria. Pooled odds ratios (OR) with 95% confidence intervals (CIs) were calculated for risk estimation. Our results indicated that mono-n-butyl phthalate (MBP), sum of di-2-ethylhexyl phthalate (ΣDEHP), and mono 3- carboxypropyl phthalate (MCPP) significantly correlated with the risk of PTB (MBP: OR = 1.23, 95% CI = 1.05-1.45; ΣDEHP: OR = 1.21, 95% CI =1.01-1.44; MCPP: OR = 1.09, 95% CI = 1.00-1.19). Pooled results showed that spontaneous PTB was associated with higher urinary levels of mono-ethyl phthalate (MEP), MCPP, mono-isobutyl phthalate (MIBP), and MBP (MBP: OR = 1.27, 95% CI = 1.02-1.58; MEP: OR = 1.19, 95% CI = 1.01-1.40; MCPP: OR = 1.15, 95% CI = 1.02-1.30; MIBP: OR = 1.38, 95% CI = 1.12-1.71). Overall, we conclude that during pregnancy, MBP, ΣDEHP, and MCPP levels are associated positively with PTB. MBP, MEP, MCPP, and MIBP levels had increased odds of spontaneous PTB. No significant associations were observed between other phthalate metabolites and PTB or spontaneous PTB. Further research is needed to verify these findings and elucidate the association of phthalate levels and PTB.

Protocol for a sequential, prospective meta-analysis to describe coronavirus disease 2019 (COVID-19) in the pregnancy and postpartum periods

We urgently need answers to basic epidemiological questions regarding SARS-CoV-2 infection in pregnant and postpartum women and its effect on their newborns. While many national registries, health facilities, and research groups are collecting relevant data, we need a collaborative and methodologically rigorous approach to better combine these data and address knowledge gaps, especially those related to rare outcomes. We propose that using a sequential, prospective meta-analysis (PMA) is the best approach to generate data for policy- and practice-oriented guidelines. As the pandemic evolves, additional studies identified retrospectively by the steering committee or through living systematic reviews will be invited to participate in this PMA. Investigators can contribute to the PMA by either submitting individual patient data or running standardized code to generate aggregate data estimates. For the primary analysis, we will pool data using two-stage meta-analysis methods. The meta-analyses will be updated as additional data accrue in each contributing study and as additional studies meet study-specific time or data accrual thresholds for sharing. At the time of publication, investigators of 25 studies, including more than 76,000 pregnancies, in 41 countries had agreed to share data for this analysis. Among the included studies, 12 have a contemporaneous comparison group of pregnancies without COVID-19, and four studies include a comparison group of non-pregnant women of reproductive age with COVID-19. Protocols and updates will be maintained publicly. Results will be shared with key stakeholders, including the World Health Organization (WHO) Maternal, Newborn, Child, and Adolescent Health (MNCAH) Research Working Group. Data contributors will share results with local stakeholders. Scientific publications will be published in open-access journals on an ongoing basis.

Assessing and visualizing fragility of clinical results with binary outcomes in R using the fragility package

With the growing concerns about research reproducibility and replicability, the assessment of scientific results' fragility (or robustness) has been of increasing interest. The fragility index was proposed to quantify the robustness of statistical significance of clinical studies with binary outcomes. It is defined as the minimal event status modifications that can alter statistical significance. It helps clinicians evaluate the reliability of the conclusions. Many factors may affect the fragility index, including the treatment groups in which event status is modified, the statistical methods used for testing for the association between treatments and outcomes, and the pre-specified significance level. In addition to assessing the fragility of individual studies, the fragility index was recently extended to both conventional pairwise meta-analyses and network meta-analyses of multiple treatment comparisons. It is not straightforward for clinicians to calculate these measures and visualize the results. We have developed an R package called "fragility" to offer user-friendly functions for such purposes. This article provides an overview of methods for assessing and visualizing the fragility of individual studies as well as pairwise and network meta-analyses, introduces the usage of the "fragility" package, and illustrates the implementations with several worked examples.

Association between influenza vaccination, all-cause mortality and cardiovascular mortality: a protocol for a living systematic review and prospective meta-analysis

INTRODUCTION

Influenza virus infection is known to increase the risk of cardiovascular events, especially in populations with pre-existing cardiovascular disease (CVD). Considering that influenza is vaccine preventable, international guidelines recommend high-risk populations with CVD receive an influenza vaccine every year. However, there are various classifications of recommendations and levels of evidence. Previous systematic reviews concluded uncertain evidence on influenza vaccine efficacy for preventing cardiovascular events in the general population or in populations with pre-existing CVD. Limited safety data of influenza vaccines were reported for populations with pre-existing CVD. Randomised controlled trials with larger sample sizes relative to previous studies are emerging, the findings of these trials are likely to be highly influential on summary efficacy estimates.

METHODS AND ANALYSIS

We aim to perform a living systematic review and a prospective meta-analysis to evaluate the efficacy and safety of influenza vaccines compared with no vaccines or placebo for preventing mortality or CVD events in the general population and in populations with pre-existing CVD. Any types of randomised controlled trial and observational study meeting the Population, Intervention, Comparator, Outcome and Study design criteria for the research question will be selected for inclusion. The living systematic review status will be maintained for 3 years with an update for every 6 months. Mainstream medical literature databases will be independently searched by two authors with predefined strategies. Two authors will perform the risk of bias assessment with consensus. Narrative synthesis and meta-analyses will be performed to summarise the results.

ETHICS AND DISSEMINATION

Formal ethical review is not required as this study does not involve primary data collection. We will publish results of the living systematic review and prospective meta-analysis in a peer-reviewed journal. Findings will also be presented at relevant meetings.

PROSPERO REGISTRATION NUMBER

CRD42021222519.

Microbe-Mediated Thermotolerance in Plants and Pertinent Mechanisms- A Meta-Analysis and Review

Microbial symbionts can mediate plant stress responses by enhancing thermal tolerance, but less attention has been paid to measuring these effects across plant-microbe studies. We performed a meta-analysis of published studies as well as discussed with relevant literature to determine how the symbionts influence plant responses under non-stressed versus thermal-stressed conditions. As compared to non-inoculated plants, inoculated plants had significantly higher biomass and photosynthesis under heat stress conditions. A significantly decreased accumulation of malondialdehyde (MDA) and hydrogen peroxide (H2O2) indicated a lower oxidation level in the colonized plants, which was also correlated with the higher activity of catalase, peroxidase, glutathione reductase enzymes due to microbial colonization under heat stress. However, the activity of superoxide dismutase, ascorbate oxidase, ascorbate peroxidase, and proline were variable. Our meta-analysis revealed that microbial colonization influenced plant growth and physiology, but their effects were more noticeable when their host plants were exposed to high-temperature stress than when they grew under ambient temperature conditions. We discussed the mechanisms of microbial conferred plant thermotolerance, including at the molecular level based on the available literature. Further, we highlighted and proposed future directions toward exploring the effects of symbionts on the heat tolerances of plants for their implications in sustainable agricultural production.

How informative were early SARS-CoV-2 treatment and prevention trials? a longitudinal cohort analysis of trials registered on ClinicalTrials.gov

Background

Early in the SARS-CoV-2 pandemic, commentators warned that some COVID trials were inadequately conceived, designed and reported. Here, we retrospectively assess the prevalence of informative COVID trials launched in the first 6 months of the pandemic.

Methods

Based on prespecified eligibility criteria, we created a cohort of Phase 1/2, Phase 2, Phase 2/3 and Phase 3 SARS-CoV-2 treatment and prevention efficacy trials that were initiated from 2020-01-01 to 2020-06-30 using ClinicalTrials.gov registration records. We excluded trials evaluating behavioural interventions and natural products, which are not regulated by the U.S. Food and Drug Administration (FDA). We evaluated trials on 3 criteria of informativeness: potential redundancy (comparing trial phase, type, patient-participant characteristics, treatment regimen, comparator arms and primary outcome), trials design (according to the recommendations set-out in the May 2020 FDA guidance document on SARS-CoV-2 treatment and prevention trials) and feasibility of patient-participant recruitment (based on timeliness and success of recruitment).

Results

We included all 500 eligible trials in our cohort, 58% of which were Phase 2 and 84.8% were directed towards the treatment of SARS-CoV-2. Close to one third of trials met all three criteria and were deemed informative (29.9% (95% Confidence Interval 23.7–36.9)). The proportion of potentially redundant trials in our cohort was 4.1%. Over half of the trials in our cohort (56.2%) did not meet our criteria for high quality trial design. The proportion of trials with infeasible patient-participant recruitment was 22.6%.

Conclusions

Less than one third of COVID-19 trials registered on ClinicalTrials.gov during the first six months met all three criteria for informativeness. Shortcomings in trial design, recruitment feasibility and redundancy reflect longstanding weaknesses in the clinical research enterprise that were likely amplified by the exceptional circumstances of a pandemic.

Transforming Obesity Prevention for CHILDren (TOPCHILD) Collaboration: protocol for a systematic review with individual participant data meta-analysis of behavioural interventions for the prevention of early childhood obesity

INTRODUCTION

Behavioural interventions in early life appear to show some effect in reducing childhood overweight and obesity. However, uncertainty remains regarding their overall effectiveness, and whether effectiveness differs among key subgroups. These evidence gaps have prompted an increase in very early childhood obesity prevention trials worldwide. Combining the individual participant data (IPD) from these trials will enhance statistical power to determine overall effectiveness and enable examination of individual and trial-level subgroups. We present a protocol for a systematic review with IPD meta-analysis to evaluate the effectiveness of obesity prevention interventions commencing antenatally or in the first year after birth, and to explore whether there are differential effects among key subgroups.

METHODS AND ANALYSIS

Systematic searches of Medline, Embase, Cochrane Central Register of Controlled Trials, Cumulative Index to Nursing and Allied Health Literature (CINAHL), PsycInfo and trial registries for all ongoing and completed randomised controlled trials evaluating behavioural interventions for the prevention of early childhood obesity have been completed up to March 2021 and will be updated annually to include additional trials. Eligible trialists will be asked to share their IPD; if unavailable, aggregate data will be used where possible. An IPD meta-analysis and a nested prospective meta-analysis will be performed using methodologies recommended by the Cochrane Collaboration. The primary outcome will be body mass index z-score at age 24±6 months using WHO Growth Standards, and effect differences will be explored among prespecified individual and trial-level subgroups. Secondary outcomes include other child weight-related measures, infant feeding, dietary intake, physical activity, sedentary behaviours, sleep, parenting measures and adverse events.

ETHICS AND DISSEMINATION

Approved by The University of Sydney Human Research Ethics Committee (2020/273) and Flinders University Social and Behavioural Research Ethics Committee (HREC CIA2133-1). Results will be relevant to clinicians, child health services, researchers, policy-makers and families, and will be disseminated via publications, presentations and media releases.

PROSPERO REGISTRATION NUMBER

CRD42020177408.

Diets for weight management in adults with type 2 diabetes: an umbrella review of published meta-analyses and systematic review of trials of diets for diabetes remission

AIMS/HYPOTHESIS

Weight reduction is fundamental for type 2 diabetes management and remission, but uncertainty exists over which diet type is best to achieve and maintain weight loss. We evaluated dietary approaches for weight loss, and remission, in people with type 2 diabetes to inform practice and clinical guidelines.

METHODS

First, we conducted a systematic review of published meta-analyses of RCTs of weight-loss diets. We searched MEDLINE (Ovid), PubMed, Web of Science and Cochrane Database of Systematic Reviews, up to 7 May 2021. We synthesised weight loss findings stratified by diet types and assessed meta-analyses quality with A Measurement Tool to Assess Systematic Reviews (AMSTAR) 2. We assessed certainty of pooled results of each meta-analysis using Grading of Recommendations, Assessment, Development and Evaluations (GRADE) (PROSPERO CRD42020169258). Second, we conducted a systematic review of any intervention studies reporting type 2 diabetes remission with weight-loss diets, in MEDLINE (via PubMed), Embase and Cochrane Central Register of Controlled Trials, up to 10 May 2021. Findings were synthesised by diet type and study quality (Cochrane Risk of Bias tool 2.0 and Risk Of Bias In Non-randomised Studies - of Interventions [ROBINS-I]), with GRADE applied (PROSPERO CRD42020208878).

RESULTS

We identified 19 meta-analyses of weight-loss diets, involving 2-23 primary trials (n = 100-1587), published 2013-2021. Twelve were 'critically low' or 'low' AMSTAR 2 quality, with seven 'high' quality. Greatest weight loss was reported with very low energy diets, 1.7-2.1 MJ/day (400-500 kcal) for 8-12 weeks (high-quality meta-analysis, GRADE low), achieving 6.6 kg (95% CI -9.5, -3.7) greater weight loss than low-energy diets (4.2-6.3 MJ/day [1000-1500 kcal]). Formula meal replacements (high quality, GRADE moderate) achieved 2.4 kg (95% CI -3.3, -1.4) greater weight loss over 12-52 weeks. Low-carbohydrate diets were no better for weight loss than higher-carbohydrate/low-fat diets (high quality, GRADE high). High-protein, Mediterranean, high-monounsaturated-fatty-acid, vegetarian and low-glycaemic-index diets all achieved minimal (0.3-2 kg) or no difference from control diets (low to critically low quality, GRADE very low/moderate). For type 2 diabetes remission, of 373 records, 16 met inclusion criteria. Remissions at 1 year were reported for a median 54% of participants in RCTs including initial low-energy total diet replacement (low-risk-of-bias study, GRADE high), and 11% and 15% for meal replacements and Mediterranean diets, respectively (some concerns for risk of bias in studies, GRADE moderate/low). For ketogenic/very low-carbohydrate and very low-energy food-based diets, the evidence for remission (20% and 22%, respectively) has serious and critical risk of bias, and GRADE certainty is very low.

CONCLUSIONS/INTERPRETATION

Published meta-analyses of hypocaloric diets for weight management in people with type 2 diabetes do not support any particular macronutrient profile or style over others. Very low energy diets and formula meal replacement appear the most effective approaches, generally providing less energy than self-administered food-based diets. Programmes including a hypocaloric formula 'total diet replacement' induction phase were most effective for type 2 diabetes remission. Most of the evidence is restricted to 1 year or less. Well-conducted research is needed to assess longer-term impacts on weight, glycaemic control, clinical outcomes and diabetes complications.

Efficacy and safety of Ayurveda interventions for sinusitis: a systematic review and meta-analysis

OBJECTIVES

To provide a broad evaluation of the efficacy and safety of Ayurveda interventions for the management of sinusitis.

METHODS

Five electronic databases for published research articles, three databases for the dissertation/doctoral thesis works, clinical trial registries, and hand searches were done till May 2021. All comparative clinical trials recruiting sinusitis patients of any age group, receiving Ayurveda intervention, regardless of forms, dosages, and ingredients, for not less than one week were included. The data extraction and the risk of bias (RoB) assessment were done by two reviewers independently.

RESULTS

A total of 2,824 records were identified, of which 09 randomized parallel arms trials met inclusion criteria. No studies were found comparing Ayurveda vs. placebo or non-Ayurveda interventions. Combined Ayurveda therapy (CT) was statistically more beneficial compared with either procedural or non-procedural Ayurveda therapy alone in reducing symptoms nasal discharge (standardized MD -0.71, 95% CI -1.16 to -0.26, I ² 58%, 210 participants) and headache (standardized MD -0.44, 95% CI -0.86 to -0.02, I ² 56%, 218 participants), however, no significant difference was found in reducing symptoms nasal obstruction and loss of smell. No data related to the safety of Ayurveda intervention was found. All the trials (09) were having 'high' to 'some concern' overall bias.

CONCLUSIONS

Although individual studies appeared to produce positive results, very low certainty of total effect hindered to arrive at any conclusion regarding efficacy or safety of Ayurveda interventions for sinusitis. There is a need for well-designed-executed-reported clinical studies on clinically relevant outcomes.

PROSPERO REGISTRATION NUMBER

CRD42018103995.

Protocol for the development of Core Outcome Sets for Early intervention trials to Prevent Obesity in CHildren (COS-EPOCH)

INTRODUCTION

Childhood overweight and obesity is prevalent in the first 5 years of life, and can result in significant health and economic consequences over the lifetime. The outcomes currently measured and reported in randomised controlled trials of early childhood obesity prevention interventions to reduce this burden of obesity are heterogeneous, and measured in a variety of ways. This variability limits the comparability of findings between studies, and contributes to research waste. This protocol presents the methodology for the development of two core outcome sets (COS) for obesity prevention interventions in children aged from 1 to 5 years from a singular development process: (1) a COS for interventions targeting physical activity and sedentary behaviour and (2) a COS for interventions targeting child feeding and dietary intake. Core outcomes related to physical activity and sedentary behaviour in children aged ≤1 year will also be identified to complement an existing COS for early feeding interventions, and provide a broader set of core outcomes in this age range. This will result in a suite of COS useful for measuring and reporting outcomes in early childhood obesity prevention studies, including multicomponent interventions.

METHODS AND ANALYSIS

Development of the COS will follow international best practice guidelines. A scoping review of trial registries will identify commonly reported outcomes and associated measurement instruments. Key stakeholders involved in obesity prevention, including policy-makers/funders, parents, researchers, health practitioners and community and organisational stakeholders will participate in an e-Delphi study and consensus meeting regarding inclusion of outcomes in the COS. Finally, recommended outcome measure instruments will be identified through literature review and group consensus.

ETHICS AND DISSEMINATION

Deakin University Human Research Ethics Committee (HEAG-H 231_2020). The COS will be disseminated through peer-reviewed publications and engagement with key stakeholders.

Data sharing-trialists' plans at registration, attitudes, barriers and facilitators: A cohort study and cross-sectional survey

Data unavailability impedes research transparency and is a major problem for individual participant data (IPD) meta-analyses as it reduces statistical power, increases risk of bias, and may even preclude completion. The primary objectives of this study were to determine IPD sharing plans reported in recently registered clinical trial registration records, how data sharing commitment relates to clinical trial characteristics, and principal investigators' attitudes, motivations and barriers to data sharing. The secondary objective was to derive recommendations to overcome identified barriers to data sharing. This was a retrospective cohort study of all interventional trials registered on the Australian New Zealand Clinical Trials Registry (ANZCTR) from 1 December 2018 to 30 November 2019, and an online cross-sectional survey of their principal investigators. In the cohort study of all clinical trials registered on the ANZCTR in the study period (n = 1517), commitment to share data was low (22%, 329/1517). In the cross-sectional survey (n = 281, 23% response rate), principal investigators showed strong support for the concept of data sharing (77%, 216/281) but a substantially lower intention to actually share data from their clinical trials (40%, 111/281). Major barriers to data sharing included lacking informed consent to share data, protecting participant confidentiality and preventing misinterpretation of data or misleading secondary analyses. There is a gap between high in-principle support for data sharing, and low in-practice intention from investigators to share data from their own clinical trials. Multiple pathways exist to bridge this gap by addressing the identified barriers to data sharing.

A framework for prospective, adaptive meta-analysis (FAME) of aggregate data from randomised trials

BACKGROUND

The vast majority of systematic reviews are planned retrospectively, once most eligible trials have completed and reported, and are based on aggregate data that can be extracted from publications. Prior knowledge of trial results can introduce bias into both review and meta-analysis methods, and the omission of unpublished data can lead to reporting biases. We present a collaborative framework for prospective, adaptive meta-analysis (FAME) of aggregate data to provide results that are less prone to bias. Also, with FAME, we monitor how evidence from trials is accumulating, to anticipate the earliest opportunity for a potentially definitive meta-analysis.

METHODOLOGY

We developed and piloted FAME alongside 4 systematic reviews in prostate cancer, which allowed us to refine the key principles. These are to: (1) start the systematic review process early, while trials are ongoing or yet to report; (2) liaise with trial investigators to develop a detailed picture of all eligible trials; (3) prospectively assess the earliest possible timing for reliable meta-analysis based on the accumulating aggregate data; (4) develop and register (or publish) the systematic review protocol before trials produce results and seek appropriate aggregate data; (5) interpret meta-analysis results taking account of both available and unavailable data; and (6) assess the value of updating the systematic review and meta-analysis. These principles are illustrated via a hypothetical review and their application to 3 published systematic reviews.

CONCLUSIONS

FAME can reduce the potential for bias, and produce more timely, thorough and reliable systematic reviews of aggregate data.

Implementation strategies to improve statin utilization in individuals with hypercholesterolemia: a systematic review and meta-analysis

BACKGROUND

Numerous implementation strategies to improve utilization of statins in patients with hypercholesterolemia have been utilized, with varying degrees of success. The aim of this systematic review is to determine the state of evidence of implementation strategies on the uptake of statins.

METHODS AND RESULTS

This systematic review identified and categorized implementation strategies, according to the Expert Recommendations for Implementing Change (ERIC) compilation, used in studies to improve statin use. We searched Ovid MEDLINE, Embase, Scopus, Cochrane Database of Systematic Reviews, Cochrane Central Register of Controlled Trials, and Clinicaltrials.gov from inception to October 2018. All included studies were reported in English and had at least one strategy to promote statin uptake that could be categorized using the ERIC compilation. Data extraction was completed independently, in duplicate, and disagreements were resolved by consensus. We extracted LDL-C (concentration and target achievement), statin prescribing, and statin adherence (percentage and target achievement). A total of 258 strategies were used across 86 trials. The median number of strategies used was 3 (SD 2.2, range 1-13). Implementation strategy descriptions often did not include key defining characteristics: temporality was reported in 59%, dose in 52%, affected outcome in 9%, and justification in 6%. Thirty-one trials reported at least 1 of the 3 outcomes of interest: significantly reduced LDL-C (standardized mean difference [SMD] - 0.17, 95% CI - 0.27 to - 0.07, p = 0.0006; odds ratio [OR] 1.33, 95% CI 1.13 to 1.58, p = 0.0008), increased rates of statin prescribing (OR 2.21, 95% CI 1.60 to 3.06, p < 0.0001), and improved statin adherence (SMD 0.13, 95% CI 0.06 to 0.19; p = 0.0002; OR 1.30, 95% CI 1.04 to 1.63, p = 0.023). The number of implementation strategies used per study positively influenced the efficacy outcomes.

CONCLUSION

Although studies demonstrated improved statin prescribing, statin adherence, and reduced LDL-C, no single strategy or group of strategies consistently improved outcomes.

TRIAL REGISTRATION

PROSPERO CRD42018114952 .

A Review of Registered Randomized Controlled Trials for the Prevention of Obesity in Infancy

Childhood overweight and obesity is a worldwide public health issue. Our objective was to describe planned, ongoing and completed randomized controlled trials (RCTs) designed for the prevention of obesity in early childhood. Two databases (World Health Organization International Clinical Trials Registry Platform, ClinicalTrials.gov) were searched to identify RCTs with the primary aim of preventing childhood obesity and at least one outcome related to child weight. Interventions needed to start in the first two years of childhood or earlier, continue for at least 6 months postnatally, include a component related to lifestyle or behaviours, and have a follow up time of at least 2 years. We identified 29 unique RCTs, implemented since 2008, with most being undertaken in high income countries. Interventions ranged from advice on diet, activity, sleep, emotion regulation, and parenting education through to individual home visits, clinic-based consultations, or group education sessions. Eleven trials published data on child weight-related outcomes to date, though most were not sufficiently powered to detect significant effects. Many trials detected improvements in practices such as breastfeeding, screen time, and physical activity in the intervention groups compared to the control groups. Further follow-up of ongoing trials is needed to assess longer-term effects.

Umbilical Cord Management for Newborns <34 Weeks' Gestation: A Meta-analysis

CONTEXT

The International Liaison Committee on Resuscitation prioritized scientific review of umbilical cord management strategies at preterm birth.

OBJECTIVE

To determine the effects of umbilical cord management strategies (including timing of cord clamping and cord milking) in preterm infants <34 weeks' gestation.

DATA SOURCES

Cochrane Central Register of Controlled Trials, Medline, PubMed, Embase, CINAHL, and trial registries were searched through July 2019 for randomized controlled trials assessing timing of cord clamping and/or cord milking.

STUDY SELECTION

Two authors independently assessed trial eligibility, extracted data, appraised risk of bias, and assessed evidence certainty (GRADE).

DATA EXTRACTION

We identified 42 randomized controlled trials (including 5772 infants) investigating 4 different comparisons of cord management interventions.

RESULTS

Compared to early cord clamping, delayed cord clamping (DCC) and intact-cord milking (ICM) may slightly improve survival; however, both are compatible with no effect (DCC: risk ratio: 1.02, 95% confidence interval: 1.00 to 1.04, n = 2988 infants, moderate certainty evidence; ICM: risk ratio: 1.02, 95% confidence interval: 0.98 to 1.06, n = 945 infants, moderate certainty evidence). DCC and ICM both probably improve hematologic measures but may not affect major neonatal morbidities.

LIMITATIONS

For many of the included comparisons and outcomes, certainty of evidence was low. Our subgroup analyses were limited by few researchers reporting subgroup data.

CONCLUSIONS

DCC appears to be associated with some benefit for infants born <34 weeks. Cord milking needs further evidence to determine potential benefits or harms. The ideal cord management strategy for preterm infants is still unknown, but early clamping may be harmful.

[Rapid Reviews in the Time of COVID-19 - Experiences of the Competence Network Public Health COVID-19 and Proposal for a Standardized Procedure]

Ziel Im Zuge der COVID-19-Pandemie benötigen viele gesundheitsrelevante Fragestellungen rasche Antworten. Im Kompetenznetz Public Health zu COVID-19, das im März 2020 von Vertreter:innen mehrerer wissenschaftlicher Fachgesellschaften gegründet wurde, werden vielfach Rapid Reviews erstellt, um rasch evidenzbasierte, für politische Entscheidungsträger:innen nutzbare Antworten zu generieren. Ziel dieses Beitrags ist es, die praktischen Erfahrungen bei der Durchführung von Rapid Reviews im Rahmen des Kompetenznetzes Public Health zu reflektieren. Auf dieser Grundlage sollen Methoden zur qualitativ hochwertigen und praktikablen Durchführung von Rapid Reviews entwickelt werden, die insbesondere auch zur raschen Evidenzgenerierung auf der Grundlage von Beobachtungsstudien anwendbar sind.

Methodik Unter Nutzung des von Tricco et al. [1] vorgeschlagenen 8-schrittigen Vorgehens werden die aktuellen Herausforderungen beschrieben, die sich im Kompetenznetz Public Health zu COVID-19 bei der Durchführung von Rapid Reviews zu Public Health-bezogenen Fragen der COVID-19-Pandemie ergeben haben. Die 8 Schritte lauten: 1. Formulierung der Fragestellung, 2. Literatursuche, 3. Titel-Abstract- und Volltextsichtung, 4. Datenextraktion, 5. Risk of Bias-Bewertung, 6. Evidenzsynthese, 7. Dissemination, 8. Aktualisierung. Zudem werden Lösungsvorschläge im Expert:innenkonsens der Mitglieder (n=42 zum 28.01.2021) der Querschnitts-AG Rapid Reviews des Kompetenznetzes Public Health zu COVID-19 entwickelt.

Ergebnisse Vorgelegt und zur Diskussion gestellt wird ein standardisiertes Vorgehen, das sich eng an das Vorgehen der Cochrane Rapid Reviews Methods Group anlehnt und den besonderen Anforderungen von ätiologisch orientierten, häufig auch ökologischen Beobachtungsstudien zu COVID-19 Rechnung trägt.

Schlussfolgerungen Das vorgeschlagene Vorgehen bei der Durchführung von Rapid Reviews kann – ggf. über Fragestellungen zu COVID-19 hinaus – eine wichtige Grundlage einer evidenzbasierten Politikberatung bilden. Zur kurzfristigen Realisierung von methodisch hochwertigen Rapid Reviews zu neuen Fragestellungen sollten flexible und kurzfristig aktivierbare Förderkonzepte bereitgestellt werden. Wissenschaftliche Kooperationen bei der Durchführung von Rapid Reviews sollten ausgebaut werden, dabei sollten verstärkt methodisch hochwertige Ansätze wie bspw. prospektive Metaanalysen Anwendung finden.

A technical review of three clinical trials register resources indicates where improvements to the search interfaces are needed

Clinical trials registers form an important part of the search for studies in systematic reviews of intervention effectiveness but the search interfaces and functionality of registers can be challenging to search systematically and resource intensive to search well. We report a technical review of the search interfaces of three leading trials register resources: ClinicalTrials.gov, the EU Clinical Trials Register and the WHO International Clinical Trials Registers Platform. The technical review used a validated checklist to identify areas where the search interfaces of these trials register resources performed well, where performance was adequate, where performance was poor, and to identify differences between search interfaces. The review found low overall scores for each of the interfaces (ClinicalTrials.gov 55/165, the EU Clinical Trials Register 25/165, the WHO International Clinical Trials Registers Platform 32/165). This finding suggests a need for joined-up dialogue between the producers of the registers and researchers who search them via these interfaces. We also set out a series of four proposed changes which might improve the search interfaces. Trials registers are an invaluable resource in systematic reviews of intervention effectiveness. With the continued growth in systematic reviews, and initiatives such as 'AllTrials', there is an anticipated need for these resources. We conclude that small changes to the search interfaces, and improved dialogue with providers, might improve the future search functionality of these valuable resources.