Clinical trials, immunosuppression and renal transplantation: new trends in design and analysis

Design, Analysis, and Pitfalls of Clinical Trials Using Ex Situ Liver Machine Perfusion: The International Liver Transplantation Society Consensus Guidelines

BACKGROUND

Recent trials in liver machine perfusion (MP) have revealed unique challenges beyond those seen in most clinical studies. Correct trial design and interpretation of data are essential to avoid drawing conclusions that may compromise patient safety and increase costs.

METHODS

The International Liver Transplantation Society, through the Special Interest Group "DCD, Preservation and Machine Perfusion," established a working group to write consensus statements and guidelines on how future clinical trials in liver perfusion should be designed, with particular focus on relevant clinical endpoints and how different techniques of liver perfusion should be compared. Protocols, abstracts, and full published papers of clinical trials using liver MP were reviewed. The use of a simplified Grading of Recommendations Assessment, Development, and Evaluation working group (GRADE) system was attempted to assess the level of evidence. The working group presented its conclusions at the International Liver Transplantation Society consensus conference "DCD, Liver Preservation, and Machine Perfusion" held in Venice, Italy, on January 31, 2020.

RESULTS

Twelve recommendations were proposed with the main conclusions that clinical trials investigating the effect of MP in liver transplantation should (1) make the protocol publicly available before the start of the trial, (2) be adequately powered, and (3) carefully consider timing of randomization in function of the primary outcome.

CONCLUSIONS

There are issues with using accepted primary outcomes of liver transplantation trials in the context of MP trials, and no ideal endpoint could be defined by the working group. The setup of an international registry was considered vital by the working group.

A systematic literature review of methods of incorporating mortality in cost-effectiveness analyses of lipid-lowering therapies

AIMS

Cost effectiveness analysis (CEA) is a useful tool for estimating the value of an intervention in relation to alternatives. In cardiovascular disease (CVD), CEA is especially important, given the high economic and clinical burden. One key driver of value is CVD mortality prevention. However, data used to inform CEA parameters can be limited, given the difficulty in demonstrating statistically significant mortality benefit in randomized clinical trials (RCTs), due in part to the frequency of fatal events and limited trial durations. This systematic review identifies and summarizes whether published CVD-related CEAs have incorporated mortality benefits, and the methodology among those that did.

MATERIALS AND METHODS

A systematic literature review was conducted of CEAs of lipid-lowering therapies published between 2000-2017. Health technology assessments (HTA) and full-length manuscripts were included, and sources of mortality data and methods of applying mortality benefits were extracted. Results were summarized as proportions of articles to articulate common practices in CEAs of CVD.

RESULTS

This review identified 100 studies for inclusion, comprising 93 full-length manuscripts and seven HTA reviews. Among these, 99% assumed a mortality benefit in the model. However, 87 of these studies that incorporated mortality differences did so despite the trials used to inform model parameters not demonstrating statistically significant differences in mortality. None of the 12 studies that used statistically significant findings from an individual RCT were based on active control studies. In a sub-group analysis considering the 60 CEAs that incorporated a direct mortality benefit, 48 (80%) did not have RCT evidence for statistically significant benefit in CVD mortality.

LIMITATIONS AND CONCLUSIONS

The finding that few CEA models included mortality inputs from individual RCTs of lipid-lowering therapy may be surprising, as one might expect that treatment efficacy should be based on robust clinical evidence. However, regulatory requirements in CVD-related RCTs often lead to insufficient sample sizes and observation periods for detecting a difference in CVD mortality, which results in the use of intermediate outcomes, composite end-points, or meta-analysis to extrapolate long-term mortality benefit in a lifetime CEA.

Developing New Immunosuppression for the Next Generation of Transplant Recipients: The Path Forward

The development of new immunosuppressive drugs has slowed markedly over the past several years, and the outlook that improved therapy will be available to the next generation of transplant recipients is bleak. In this viewpoint, the authors outline some of important barriers to new drug development and suggest specific steps that the transplant community can take to overcome them.

Recommendations and evidence for reporting items in pediatric clinical trial protocols and reports: two systematic reviews

BACKGROUND

Complete and transparent reporting of clinical trial protocols and reports ensures that these documents are useful to all stakeholders, that bias is minimized, and that the research is not wasted. However, current studies repeatedly conclude that pediatric trial protocols and reports are not appropriately reported. Guidelines like SPIRIT (Standard Protocol Items: Recommendations for Interventional Trials) and CONSORT (Consolidated Standards of Reporting Trials) may improve reporting, but do not offer guidance on issues unique to pediatric trials. This paper reports two systematic reviews conducted to build the evidence base for the development of pediatric reporting guideline extensions: 1) SPIRIT-Children (SPIRIT-C) for pediatric trial protocols, and 2) CONSORT-Children (CONSORT-C) for pediatric trial reports.

METHOD

MEDLINE, the Cochrane Methodology Register, and reference lists of included studies were searched. Publications of any type were eligible if they included explicit recommendations or empirical evidence for the reporting of potential items in a pediatric protocol (SPIRIT-C systematic review) or trial report (CONSORT-C systematic review). Study characteristics, recommendations and evidence for pediatric extension items were extracted. Recurrent themes in the recommendations and evidence were identified and synthesized. All steps were conducted by two reviewers.

RESULTS

For the SPIRIT-C and CONSORT-C systematic reviews 366 and 429 publications were included, respectively. Recommendations were identified for 48 of 50 original reporting items and sub-items from SPIRIT, 15 of 20 potential SPIRIT-C reporting items, all 37 original CONSORT items and sub-items, and 16 of 22 potential CONSORT-C reporting items. The following overarching themes of evidence to support or refute the utility of reporting items were identified: transparency; reproducibility; interpretability; usefulness; internal validity; external validity; reporting bias; publication bias; accountability; scientific soundness; and research ethics.

CONCLUSION

These systematic reviews are the first to systematically gather evidence and recommendations for the reporting of specific items in pediatric protocols and trials. They provide useful and translatable evidence on which to build pediatric extensions to the SPIRIT and CONSORT reporting guidelines. The resulting SPIRIT-C and CONSORT-C will provide guidance to the authors of pediatric protocols and reports, respectively, helping to alleviate concerns of inappropriate and inconsistent reporting, and reduce research waste.

Development of a spreadsheet for the calculation of new tools to improve the reporting of the resultsof medical research

PRIMARY OBJECTIVE

Confidence levels, clinical significance curves and risk - benefit contours have recently been developed with the aim of improving the interpretation of clinical studies. It has been suggested that their use may complement traditional methods of result reporting (i.e. p values and 95% confidence intervals), and subsequently improve medical decision-making. These new methods have been used to report study results; however, widespread use may be hampered by the lack of available computer software. Our objective was to design user-friendly software to enable researchers to use these statistical methods.

RESEARCH DESIGN

A spreadsheet was designed to calculate these statistics for the assessment of two arm medical studies. The spreadsheet was tested using a wide range of input data and operating systems. User-friendliness was tested by researchers who had no background in statistics.

MAIN OUTCOMES AND RESULTS

The confidence calculator was successfully designed, and found to be user-friendly. The spreadsheet is MS Excel-based to allow wide usage. The spreadsheet is freely available from the author and from the web site http://www.primercollaboration.com/Tools/tools.html.

CONCLUSIONS

We have successfully designed a spreadsheet that is simple to use and freely accessible for researchers. This is the first such software that calculates confidence levels, clinical significance curves, and risk - benefit contours.