Anti-Vascular Endothelial Growth Factor Drugs Compared With Panretinal Photocoagulation for the Treatment of Proliferative Diabetic Retinopathy: A Cost-Effectiveness Analysis.

OBJECTIVES: This study aimed to evaluate the cost-effectiveness of anti-vascular endothelial growth factor drugs (anti-VEGFs) compared with panretinal photocoagulation (PRP) for treating proliferative diabetic retinopathy (PDR) in the United Kingdom. METHODS: A discrete event simulation model was developed, informed by individual participant data meta-analysis. The model captures treatment effects on best corrected visual acuity in both eyes, and the occurrence of diabetic macular edema and vitreous hemorrhage. The model also estimates the value of undertaking further research to resolve decision uncertainty. RESULTS: Anti-VEGFs are unlikely to generate clinically meaningful benefits over PRP. The model predicted anti-VEGFs be more costly and similarly effective as PRP, generating 0.029 fewer quality-adjusted life-years at an additional cost of £3688, with a net health benefit of -0.214 at a £20 000 willingness-to-pay threshold. Scenario analysis results suggest that only under very select conditions may anti-VEGFs offer potential for cost-effective treatment of PDR. The consequences of loss to follow-up were an important driver of model outcomes. CONCLUSIONS: Anti-VEGFs are unlikely to be a cost-effective treatment for early PDR compared with PRP. Anti-VEGFs are generally associated with higher costs and similar health outcomes across various scenarios. Although anti-VEGFs were associated with lower diabetic macular edema rates, the number of cases avoided is insufficient to offset the additional treatment costs. Key uncertainties relate to the long-term comparative effectiveness of anti-VEGFs, particularly considering the real-world rates and consequences of treatment nonadherence. Further research on long-term visual acuity and rates of vision-threatening complications may be beneficial in resolving uncertainties.

[The PRISMA 2020 statement: an updated guideline for reporting systematic reviewsDeclaración PRISMA 2020: una guía actualizada para la publicación de revisiones sistemáticas]. / A declaração PRISMA 2020: diretriz atualizada para relatar revisões sistemáticas.

The Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement, published in 2009, was designed to help systematic reviewers transparently report why the review was done, what the authors did, and what they found. Over the past decade, advances in systematic review methodology and terminology have necessitated an update to the guideline. The PRISMA 2020 statement replaces the 2009 statement and includes new reporting guidance that reflects advances in methods to identify, select, appraise, and synthesise studies. The structure and presentation of the items have been modified to facilitate implementation. In this article, we present the PRISMA 2020 27-item checklist, an expanded checklist that details reporting recommendations for each item, the PRISMA 2020 abstract checklist, and the revised flow diagrams for original and updated reviews.

La declaración PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses), publicada en 2009, se diseñó para ayudar a los autores de revisiones sistemáticas a documentar de manera transparente el porqué de la revisión, qué hicieron los autores y qué encontraron. Durante la última década, ha habido muchos avances en la metodología y terminología de las revisiones sistemáticas, lo que ha requerido una actualización de esta guía. La declaración PRISMA 2020 sustituye a la declaración de 2009 e incluye una nueva guía de presentación de las publicaciones que refleja los avances en los métodos para identificar, seleccionar, evaluar y sintetizar estudios. La estructura y la presentación de los ítems ha sido modificada para facilitar su implementación. En este artículo, presentamos la lista de verificación PRISMA 2020 con 27 ítems, y una lista de verificación ampliada que detalla las recomendaciones en la publicación de cada ítem, la lista de verificación del resumen estructurado PRISMA 2020 y el diagrama de flujo revisado para revisiones sistemáticas.

The PRISMA 2020 statement: An updated guideline for reporting systematic reviews.

Matthew Page and co-authors describe PRISMA 2020, an updated reporting guideline for systematic reviews and meta-analyses.

Comparison of aggregate and individual participant data approaches to meta-analysis of randomised trials: An observational study.

BACKGROUND: It remains unclear when standard systematic reviews and meta-analyses that rely on published aggregate data (AD) can provide robust clinical conclusions. We aimed to compare the results from a large cohort of systematic reviews and meta-analyses based on individual participant data (IPD) with meta-analyses of published AD, to establish when the latter are most likely to be reliable and when the IPD approach might be required. METHODS AND FINDINGS: We used 18 cancer systematic reviews that included IPD meta-analyses: all of those completed and published by the Meta-analysis Group of the MRC Clinical Trials Unit from 1991 to 2010. We extracted or estimated hazard ratios (HRs) and standard errors (SEs) for survival from trial reports and compared these with IPD equivalents at both the trial and meta-analysis level. We also extracted or estimated the number of events. We used paired t tests to assess whether HRs and SEs from published AD differed on average from those from IPD. We assessed agreement, and whether this was associated with trial or meta-analysis characteristics, using the approach of Bland and Altman. The 18 systematic reviews comprised 238 unique trials or trial comparisons, including 37,082 participants. A HR and SE could be generated for 127 trials, representing 53% of the trials and approximately 79% of eligible participants. On average, trial HRs derived from published AD were slightly more in favour of the research interventions than those from IPD (HRAD to HRIPD ratio = 0.95, p = 0.007), but the limits of agreement show that for individual trials, the HRs could deviate substantially. These limits narrowed with an increasing number of participants (p < 0.001) or a greater number (p < 0.001) or proportion (p < 0.001) of events in the AD. On average, meta-analysis HRs from published AD slightly tended to favour the research interventions whether based on fixed-effect (HRAD to HRIPD ratio = 0.97, p = 0.088) or random-effects (HRAD to HRIPD ratio = 0.96, p = 0.044) models, but the limits of agreement show that for individual meta-analyses, agreement was much more variable. These limits tended to narrow with an increasing number (p = 0.077) or proportion of events (p = 0.11) in the AD. However, even when the information size of the AD was large, individual meta-analysis HRs could still differ from their IPD equivalents by a relative 10% in favour of the research intervention to 5% in favour of control. We utilised the results to construct a decision tree for assessing whether an AD meta-analysis includes sufficient information, and when estimates of effects are most likely to be reliable. A lack of power at the meta-analysis level may have prevented us identifying additional factors associated with the reliability of AD meta-analyses, and we cannot be sure that our results are generalisable to all outcomes and effect measures. CONCLUSIONS: In this study we found that HRs from published AD were most likely to agree with those from IPD when the information size was large. Based on these findings, we provide guidance for determining systematically when standard AD meta-analysis will likely generate robust clinical conclusions, and when the IPD approach will add considerable value.

Sharing Roles and Control in Pediatric Low Risk Febrile Neutropenia: A Multicenter Focus Group Discussion Study Involving Patients, Parents, and Health Care Professionals.

INTRODUCTION: Reducing treatment intensity for pediatric low risk febrile neutropenia may improve quality of life, and reduce hospital-acquired infections and costs. Key stakeholders' attitudes toward early discharge regimens are unknown. This study explored perceptions of reduced therapy regimens in the United Kingdom. MATERIALS AND METHODS: Three study sites were purposively selected for their approaches to risk stratification, treatment protocols, shared care networks, and geographical spread of patients. Patients aged 13 to 18 years, parents of children of all ages and health care professionals participated in focus group discussions. A constant comparison analysis was used. RESULTS: Thirty-two participants spoke of their different roles in managing febrile neutropenia and how these would change if reduced therapy regimens were implemented, how mutual trust would need to be strengthened and responsibility redistributed. Having identified a need for discretion and a desire for individualized care, negotiation within a spectrum of control allows achievement of the potential for realized discretion. Nonattendance exemplifies when control is different and families use their assessments of risk and sense of mutual trust, along with previous experiences, to make decisions. CONCLUSIONS: The significance of shared decision making in improving patient experience through sharing risks, developing mutual trust, and negotiating control to achieve individualized treatment cannot be underestimated.

PRISMA Extension for Scoping Reviews (PRISMA-ScR): Checklist and Explanation.

Scoping reviews, a type of knowledge synthesis, follow a systematic approach to map evidence on a topic and identify main concepts, theories, sources, and knowledge gaps. Although more scoping reviews are being done, their methodological and reporting quality need improvement. This document presents the PRISMA-ScR (Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews) checklist and explanation. The checklist was developed by a 24-member expert panel and 2 research leads following published guidance from the EQUATOR (Enhancing the QUAlity and Transparency Of health Research) Network. The final checklist contains 20 essential reporting items and 2 optional items. The authors provide a rationale and an example of good reporting for each item. The intent of the PRISMA-ScR is to help readers (including researchers, publishers, commissioners, policymakers, health care providers, guideline developers, and patients or consumers) develop a greater understanding of relevant terminology, core concepts, and key items to report for scoping reviews.

Meta-ethnography of experiences of early discharge, with a focus on paediatric febrile neutropenia.

PURPOSE (STATING THE MAIN PURPOSES AND RESEARCH QUESTION): Many children have no significant sequelae of febrile neutropenia. A systematic review of clinical studies demonstrated patients at low risk of septic complications can be safely treated as outpatients using oral antibiotics with low rates of treatment failure. Introducing earlier discharge may improve quality of life, reduce hospital acquired infection and reduce healthcare service pressures. However, the review raised concerns that this might not be acceptable to patients, families and healthcare professionals. METHODS: This qualitative synthesis explored experiences of early discharge in paediatric febrile neutropenia, including reports from studies of adult febrile neutropenia and from other paediatric conditions. Systematic literature searching preceded meta-ethnographic analysis, including reading the studies and determining relationships between studies, translation of studies and synthesis of these translations. RESULTS: Nine papers were included. The overarching experience of early discharge is that decision-making is complex and difficult and influenced by fear, timing and resources. From this background, we identified two distinct themes. First, participants struggled with practical consequences of treatment regimens, namely childcare, finances and follow-up. A second theme identified social and emotional issues, including isolation, relational and environmental challenges. Linking these, participants considered continuity of care and the need for information important. CONCLUSIONS: Trust and confidence appeared interdependent with resources available to families-both are required to manage early discharge. Socially informed resilience is relevant to facilitating successful discharge strategies. Interventions which foster resilience may mediate the ability and inclination of families to accept early discharge. Services have an important role in recognising and enhancing resilience.

Systematic review and meta-analysis of the risk of severe and life-threatening thromboembolism in cancer patients receiving anti-EGFR monoclonal antibodies (cetuximab or panitumumab).

Cancer-associated thromboembolism is a substantial problem in clinical practice. An increase in the level of fibrinopeptide A (a substance associated with hypercoagulable states) has been observed in humans exposed to fluorouracil. Anti-EGFR monoclonal antibodies cetuximab and panitumumab, which are now widely used in patients with metastatic colorectal cancer, could prolong the uncovering of endothelial structures resulting from flouorouracil or other co-administered agents, thus favouring several factors leading to thromboembolism. We performed a systematic review and meta-analysis of randomised, controlled trials assessing whether cancer patients receiving anti-EGFR monoclonal antibodies cetuximab and panitumumab are at increased risk of thromboembolic events. We searched electronic databases (Medline, Embase, Web of Science, Central) and reference lists. Phase II/III randomised, controlled trials comparing standard anti-cancer regimens with or without anti-EGFR monoclonal antibodies and reporting serious venous thromboembolic events were included in the analysis. Seventeen studies (12,870 patients) were considered for quantitative analysis. The relative risk (RR) for venous thromboembolism (18 comparisons) was 1.46 (95% CI 1.26 to 1.69); the RR of pulmonary embolism, on the basis of eight studies providing nine comparisons, was 1.55 (1.20 to 2.00). Cancer patients receiving anti-EGFR monoclonal antibodies-containing regimens are approximately 1.5 times more likely to experience venous or pulmonary embolism, compared to those treated with the same regimens without anti-EGFR monoclonal antibodies. Clinicians should consider patient's baseline thromboembolic risk when selecting regimens that include cetuximab or panitumumab. Potential non-reporting of these important adverse events remains a concern. PROSPERO registration number is CRD42014009165.

Predicting microbiologically defined infection in febrile neutropenic episodes in children: global individual participant data multivariable meta-analysis.

BACKGROUND: Risk-stratified management of fever with neutropenia (FN), allows intensive management of high-risk cases and early discharge of low-risk cases. No single, internationally validated, prediction model of the risk of adverse outcomes exists for children and young people. An individual patient data (IPD) meta-analysis was undertaken to devise one. METHODS: The 'Predicting Infectious Complications in Children with Cancer' (PICNICC) collaboration was formed by parent representatives, international clinical and methodological experts. Univariable and multivariable analyses, using random effects logistic regression, were undertaken to derive and internally validate a risk-prediction model for outcomes of episodes of FN based on clinical and laboratory data at presentation. RESULTS: Data came from 22 different study groups from 15 countries, of 5127 episodes of FN in 3504 patients. There were 1070 episodes in 616 patients from seven studies available for multivariable analysis. Univariable analyses showed associations with microbiologically defined infection (MDI) in many items, including higher temperature, lower white cell counts and acute myeloid leukaemia, but not age. Patients with osteosarcoma/Ewings sarcoma and those with more severe mucositis were associated with a decreased risk of MDI. The predictive model included: malignancy type, temperature, clinically 'severely unwell', haemoglobin, white cell count and absolute monocyte count. It showed moderate discrimination (AUROC 0.723, 95% confidence interval 0.711-0.759) and good calibration (calibration slope 0.95). The model was robust to bootstrap and cross-validation sensitivity analyses. CONCLUSIONS: This new prediction model for risk of MDI appears accurate. It requires prospective studies assessing implementation to assist clinicians and parents/patients in individualised decision making.

Systematic review of reduced therapy regimens for children with low risk febrile neutropenia.

PURPOSE: Reduced intensity therapy for children with low-risk febrile neutropenia may provide benefits to both patients and the health service. We have explored the safety of these regimens and the effect of timing of discharge. METHODS: Multiple electronic databases, conference abstracts and reference lists were searched. Randomised controlled trials (RCT) and prospective observational cohorts examining the location of therapy and/or the route of administration of antibiotics in people younger than 18 years who developed low-risk febrile neutropenia following treatment for cancer were included. Meta-analysis using a random effects model was conducted. I (2) assessed statistical heterogeneity not due to chance. REGISTRATION: PROSPERO (CRD42014005817). RESULTS: Thirty-seven studies involving 3205 episodes of febrile neutropenia were included; 13 RCTs and 24 prospective observational cohorts. Four safety events (two deaths, two intensive care admissions) occurred. In the RCTs, the odds ratio for treatment failure (persistence, worsening or recurrence of fever/infecting organisms, antibiotic modification, new infections, re-admission, admission to critical care or death) with outpatient treatment was 0.98 (95% confidence interval (95%CI) 0.44-2.19, I (2) = 0 %) and with oral treatment was 1.05 (95%CI 0.74-1.48, I (2) = 0 %). The estimated risk of failure using outpatient therapy from all prospective data pooled was 11.2 % (95%CI 9.7-12.8 %, I (2) = 77.2 %) and using oral antibiotics was 10.5 % (95%CI 8.9-12.3 %, I (2) = 78.3 %). The risk of failure was higher when reduced intensity therapies were used immediately after assessment, with lower rates when these were introduced after 48 hours. CONCLUSIONS: Reduced intensity therapy for specified groups is safe with low rates of treatment failure. Services should consider how these can be acceptably implemented.

Individual Participant Data (IPD) Meta-analyses of Randomised Controlled Trials: Guidance on Their Use.

Jayne Tierney and colleagues offer guidance on how to spot a well-designed and well-conducted individual participant data meta-analysis.

Adjuvant chemotherapy for resected early-stage non-small cell lung cancer.

BACKGROUND: To evaluate the effects of administering chemotherapy following surgery, or following surgery plus radiotherapy (known as adjuvant chemotherapy) in patients with early stage non-small cell lung cancer (NSCLC),we performed two systematic reviews and meta-analyses of all randomised controlled trials using individual participant data. Results were first published in The Lancet in 2010. OBJECTIVES: To compare, in terms of overall survival, time to locoregional recurrence, time to distant recurrence and recurrence-free survival:A. Surgery versus surgery plus adjuvant chemotherapyB. Surgery plus radiotherapy versus surgery plus radiotherapy plus adjuvant chemotherapyin patients with histologically diagnosed early stage NSCLC.(2)To investigate whether or not predefined patient subgroups benefit more or less from cisplatin-based chemotherapy in terms of survival. SEARCH METHODS: We supplemented MEDLINE and CANCERLIT searches (1995 to December 2013) with information from trial registers, handsearching relevant meeting proceedings and by discussion with trialists and organisations. SELECTION CRITERIA: We included trials of a) surgery versus surgery plus adjuvant chemotherapy; and b) surgery plus radiotherapy versus surgery plus radiotherapy plus adjuvant chemotherapy, provided that they randomised NSCLC patients using a method which precluded prior knowledge of treatment assignment. DATA COLLECTION AND ANALYSIS: We carried out a quantitative meta-analysis using updated information from individual participants from all randomised trials. Data from all patients were sought from those responsible for the trial. We obtained updated individual participant data (IPD) on survival, and date of last follow-up, as well as details of treatment allocated, date of randomisation, age, sex, histological cell type, stage, and performance status. To avoid potential bias, we requested information for all randomised patients, including those excluded from the investigators' original analyses. We conducted all analyses on intention-to-treat on the endpoint of survival. For trials using cisplatin-based regimens, we carried out subgroup analyses by age, sex, histological cell type, tumour stage, and performance status. MAIN RESULTS: We identified 35 trials evaluating surgery plus adjuvant chemotherapy versus surgery alone. IPD were available for 26 of these trials and our analyses are based on 8447 participants (3323 deaths) in 34 trial comparisons. There was clear evidence of a benefit of adding chemotherapy after surgery (hazard ratio (HR)= 0.86, 95% confidence interval (CI)= 0.81 to 0.92, p< 0.0001), with an absolute increase in survival of 4% at five years.We identified 15 trials evaluating surgery plus radiotherapy plus chemotherapy versus surgery plus radiotherapy alone. IPD were available for 12 of these trials and our analyses are based on 2660 participants (1909 deaths) in 13 trial comparisons. There was also evidence of a benefit of adding chemotherapy to surgery plus radiotherapy (HR= 0.88, 95% CI= 0.81 to 0.97, p= 0.009). This represents an absolute improvement in survival of 4% at five years.For both meta-analyses, we found similar benefits for recurrence outcomes and there was little variation in effect according to the type of chemotherapy, other trial characteristics or patient subgroup.We did not undertake analysis of the effects of adjuvant chemotherapy on quality of life and adverse events. Quality of life information was not routinely collected during the trials, but where toxicity was assessed and mentioned in the publications, it was thought to be manageable. We considered the risk of bias in the included trials to be low. AUTHORS' CONCLUSIONS: Results from 47 trial comparisons and 11,107 patients demonstrate the clear benefit of adjuvant chemotherapy for these patients, irrespective of whether chemotherapy was given in addition to surgery or surgery plus radiotherapy. This is the most up-to-date and complete systematic review and individual participant data (IPD) meta-analysis that has been carried out.

Preferred Reporting Items for Systematic Review and Meta-Analyses of individual participant data: the PRISMA-IPD Statement.

IMPORTANCE: Systematic reviews and meta-analyses of individual participant data (IPD) aim to collect, check, and reanalyze individual-level data from all studies addressing a particular research question and are therefore considered a gold standard approach to evidence synthesis. They are likely to be used with increasing frequency as current initiatives to share clinical trial data gain momentum and may be particularly important in reviewing controversial therapeutic areas. OBJECTIVE: To develop PRISMA-IPD as a stand-alone extension to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) Statement, tailored to the specific requirements of reporting systematic reviews and meta-analyses of IPD. Although developed primarily for reviews of randomized trials, many items will apply in other contexts, including reviews of diagnosis and prognosis. DESIGN: Development of PRISMA-IPD followed the EQUATOR Network framework guidance and used the existing standard PRISMA Statement as a starting point to draft additional relevant material. A web-based survey informed discussion at an international workshop that included researchers, clinicians, methodologists experienced in conducting systematic reviews and meta-analyses of IPD, and journal editors. The statement was drafted and iterative refinements were made by the project, advisory, and development groups. The PRISMA-IPD Development Group reached agreement on the PRISMA-IPD checklist and flow diagram by consensus. FINDINGS: Compared with standard PRISMA, the PRISMA-IPD checklist includes 3 new items that address (1) methods of checking the integrity of the IPD (such as pattern of randomization, data consistency, baseline imbalance, and missing data), (2) reporting any important issues that emerge, and (3) exploring variation (such as whether certain types of individual benefit more from the intervention than others). A further additional item was created by reorganization of standard PRISMA items relating to interpreting results. Wording was modified in 23 items to reflect the IPD approach. CONCLUSIONS AND RELEVANCE: PRISMA-IPD provides guidelines for reporting systematic reviews and meta-analyses of IPD.

Safety and effectiveness of recombinant human bone morphogenetic protein-2 for spinal fusion: a meta-analysis of individual-participant data.

BACKGROUND: Recombinant human bone morphogenetic protein-2 (rhBMP-2) is widely used to promote fusion in spinal surgery, but its safety has been questioned. PURPOSE: To evaluate the effectiveness and safety of rhBMP-2. DATA SOURCES: Individual-participant data obtained from the sponsor or investigators and data extracted from study publications identified by systematic bibliographic searches through June 2012. STUDY SELECTION: Randomized, controlled trials of rhBMP-2 versus iliac crest bone graft (ICBG) in spinal fusion surgery for degenerative disc disease and related conditions and observational studies in similar populations for investigation of adverse events. DATA EXTRACTION: Individual-participant data from 11 eligible of 17 provided trials sponsored by Medtronic (Minneapolis, Minnesota) (n = 1302) and 1 of 2 other eligible trials (n = 106) were included. Additional aggregate adverse event data were extracted from 35 published observational studies. DATA SYNTHESIS: Primary outcomes were pain (assessed with the Oswestry Disability Index [ODI] or Short Form-36), fusion, and adverse events. At 24 months, ODI scores were 3.5% lower (better) with rhBMP-2 than with ICBG (95% CI, 0.5% to 6.5%) and radiographic fusion was 12% higher (CI, 2% to 23%). At or shortly after surgery, pain was more common with rhBMP-2 (odds ratio, 1.78 [CI, 1.06 to 2.95]). Cancer was more common after rhBMP-2 (relative risk, 1.98 [CI, 0.86 to 4.54]), but the small number of events precluded definite conclusions. LIMITATION: The observational studies were diverse and at risk of bias. CONCLUSION: At 24 months, rhBMP-2 increases fusion rates, reduces pain by a clinically insignificant amount, and increases early postsurgical pain compared with ICBG. Evidence of increased cancer incidence is inconclusive. PRIMARY FUNDING SOURCE: Yale University Open Data Access Project.

A structured approach to information retrieval improved identification of funding and researchers' conflicts of interest in trials included in Cochrane reviews.

OBJECTIVES: To compare the contemporary Cochrane review approach for retrieving information on trial funding and researchers' conflicts of interest with a structured approach for information retrieval. STUDY DESIGN AND SETTING: Methodological study of 100 Cochrane reviews from August to December 2020 and one randomly selected trial from each review. Reporting of trial funding and researchers' conflicts of interest in reviews was compared with information identified using a structured retrieval process, and time to retrieve information was noted. We also formulated a guide to systematic reviewers for efficient information retrieval. RESULTS: Sixty-eight of 100 Cochrane reviews reported trial funding and 24 reported trial researchers' conflicts of interest. A simple structured approach, searching only trial publications (including conflicts of interest disclosure forms), identified funding for 16 additional trials and conflicts of interest information for 39 additional trials. A comprehensive structured approach, searching multiple information sources, identified funding for two additional trials and conflicts of interest for 14 additional trials. The median time to retrieve information was 10 minutes per trial (interquartile range: 7-15) for the simple approach and 20 minutes (11-43) for the comprehensive approach. CONCLUSION: A structured information retrieval approach improves identification of funding and researchers' conflicts of interest in trials included in Cochrane reviews.

Using individual participant data to improve network meta-analysis projects.

A network meta-analysis combines the evidence from existing randomised trials about the comparative efficacy of multiple treatments. It allows direct and indirect evidence about each comparison to be included in the same analysis, and provides a coherent framework to compare and rank treatments. A traditional network meta-analysis uses aggregate data (eg, treatment effect estimates and standard errors) obtained from publications or trial investigators. An alternative approach is to obtain, check, harmonise and meta-analyse the individual participant data (IPD) from each trial. In this article, we describe potential advantages of IPD for network meta-analysis projects, emphasising five key benefits: (1) improving the quality and scope of information available for inclusion in the meta-analysis, (2) examining and plotting distributions of covariates across trials (eg, for potential effect modifiers), (3) standardising and improving the analysis of each trial, (4) adjusting for prognostic factors to allow a network meta-analysis of conditional treatment effects and (5) including treatment-covariate interactions (effect modifiers) to allow relative treatment effects to vary by participant-level covariate values (eg, age, baseline depression score). A running theme of all these benefits is that they help examine and reduce heterogeneity (differences in the true treatment effect between trials) and inconsistency (differences in the true treatment effect between direct and indirect evidence) in the network. As a consequence, an IPD network meta-analysis has the potential for more precise, reliable and informative results for clinical practice and even allows treatment comparisons to be made for individual patients and targeted populations conditional on their particular characteristics.

Retrieval barriers in individual participant data reviews with network meta-analysis.

OBJECTIVES: Individual participant data (IPD) from randomised controlled trials (RCTs) can be used in network meta-analysis (NMA) to underpin patient care and are the best analyses to support the development of guidelines about the use of healthcare interventions for a specific condition. However, barriers to IPD retrieval pose a major threat. The aim of this study was to present barriers we encountered during retrieval of IPD from RCTs in two published systematic reviews with IPD-NMA. METHODS: We evaluated retrieval of IPD from RCTs for IPD-NMA in Alzheimer's dementia and type 1 diabetes. We requested IPD from authors, industry sponsors and data repositories, and recorded IPD retrieval, reasons for IPD unavailability, and retrieval challenges. RESULTS: In total, we identified 108 RCTs: 78 industry sponsored, 11 publicly sponsored and 19 with no funding information. After failing to obtain IPD from any trial authors, we requested it from industry sponsors. Seven of the 17 industry sponsors shared IPD for 12 950 participants (59%) through proprietary-specific data sharing platforms from 26 RCTs (33%). We found that lack of RCT identifiers (eg, National Clinical Trial number) and unclear data ownership were major challenges in IPD retrieval. Incomplete information in retrieved datasets was another important problem that led to exclusion of RCTs from the NMA. There were also practical challenges in obtaining IPD from or analysing it within platforms, and additional costs were incurred in accessing IPD this way. CONCLUSIONS: We found no clear evidence of retrieval bias (where IPD availability was linked to trial findings) in either IPD-NMA, but because retrieval bias could impact NMA findings, subsequent decision-making and guideline development, this should be considered when assessing risk of bias in IPD syntheses.

Systematic review and meta-analysis of the value of initial biomarkers in predicting adverse outcome in febrile neutropenic episodes in children and young people with cancer.

BACKGROUND: Febrile neutropenia is a frequently occurring and occasionally life-threatening complication of treatment for childhood cancer. Many biomarkers have been proposed as predictors of adverse events. We aimed to undertake a systematic review and meta-analysis to summarize evidence on the discriminatory ability of initial serum biomarkers of febrile neutropenic episodes in children and young people. METHODS: This review was conducted in accordance with the Center for Reviews and Dissemination Methods, using three random effects models to undertake meta-analysis. It was registered with the HTA Registry of systematic reviews, CRD32009100485. RESULTS: We found that 25 studies exploring 14 different biomarkers were assessed in 3,585 episodes of febrile neutropenia. C-reactive protein (CRP), pro-calcitonin (PCT), and interleukin-6 (IL6) were subject to quantitative meta-analysis, and revealed huge inconsistencies and heterogeneity in the studies included in this review. Only CRP has been evaluated in assessing its value over the predictive value of simple clinical decision rules. CONCLUSIONS: The limited data available describing the predictive value of biomarkers in the setting of pediatric febrile neutropenia mean firm conclusions cannot yet be reached, although the use of IL6, IL8 and procalcitonin warrant further study.

Estimating interactions in individual participant data meta-analysis: a comparison of methods in practice.

Medical interventions may be more effective in some types of individuals than others and identifying characteristics that modify the effectiveness of an intervention is a cornerstone of precision or stratified medicine. The opportunity for detailed examination of treatment-covariate interactions can be an important driver for undertaking an individual participant data (IPD) meta-analysis, rather than a meta-analysis using aggregate data. A number of recent modelling approaches are available. We apply these methods to the Perinatal Antiplatelet Review of International Studies (PARIS) Collaboration IPD dataset and compare estimates between them. We discuss the practical implications of applying these methods, which may be of interest to aid meta-analysists in the use of these, often complex models.Models compared included the two-stage meta-analysis of interaction terms and one-stage models which fit multiple random effects and separate within and between trial information. Models were fitted for nine covariates and five binary outcomes and results compared.Interaction terms produced by the methods were generally consistent. We show that where data are sparse and there is low heterogeneity in the covariate distributions across trials, the meta-analysis of interactions may produce unstable estimates and have issues with convergence. In this IPD dataset, varying assumptions by using multiple random effects in one-stage models or using only within trial information made little difference to the estimates of treatment-covariate interaction. Method choice will depend on datasets characteristics and individual preference.

Extent and nature of duplication in PROSPERO using COVID-19-related registrations: a retrospective investigation and survey.

OBJECTIVES: During COVID-19, the International Prospective Register of Systematic Reviews (PROSPERO) experienced a surge in registrations for COVID-19-related systematic reviews, and duplication of research questions became apparent. Duplication can waste funding, time and research effort and make policy making more difficult.This project explored the extent of and reasons for duplication of COVID-19-related systematic review registrations in PROSPERO during the pandemic. DESIGN: Retrospective analysis of COVID-19-related registrations in PROSPERO, and a qualitative survey. SETTING: PROSPERO was searched for registrations related to four COVID-19 research areas: epidemiology, rehabilitation, transmission and treatments. METHODS: Records identified were compared using Population, Intervention/Exposure, Comparator, Outcome, Study Design (PICOS) elements of PROSPERO registration forms. Registrations with similar or identical PICOS were evaluated further as 'duplicates'.Authors of 'duplicate' registrations were invited to complete a survey asking whether they searched PROSPERO prior to registration, identified similar reviews and, if so, why they continued with their review. RESULTS: 1054 COVID-19 reviews were registered between March 2020 and January 2021, of which 138 were submitted when at least one similar protocol was already registered in PROSPERO. Duplication was greatest in reviews of COVID-19 treatments; for example, there were 14 similar reviews evaluating the efficacy of hydroxychloroquine.From 138 authors invited to take part in the survey, we received 41 responses. Most respondents said that they identified similar reviews when they searched PROSPERO prior to registration. Main reasons given for 'duplication' were differences in PICOS or planned analyses (n=13), poor quality of previous registrations (n=2) and the need to update evidence (n=3). CONCLUSIONS: This research highlights that registration of similar and duplicate systematic reviews related to COVID-19 in PROSPERO occurred frequently. Awareness of research waste is required, and initial checking for similar reviews should be embedded within good review practice.