The Placebo Response in Double-Blind Randomised Trials Evaluating Regenerative Therapies for Parkinson’s Disease: A Systematic Review and Meta-Analysis

In the field of stem cell technologies, exciting advances are taking place leading to translational research to develop cell-based therapies which may replace dopamine releasing neurons lost in patients with Parkinson’s disease (PD). A major influence on trial design has been the assumption that the use of sham operated comparator groups is required in the implementation of randomised double-blind trials to evaluate the placebo response and effects associated with the surgical implantation of cells. The aim of the present review is to identify the improvements in motor functioning and striatal dopamine release in patients with PD who have undergone sham surgery. Of the nine published trials, there was at the designated endpoints, a pooled average improvement of 4.3 units, with 95% confidence interval of 3.1 to 5.6 on the motor subscale of the Unified Parkinson’s Disease Scale in the ‘OFF’ state. This effect size indicates a moderate degree of improvement in the motor functioning of the patients in the sham surgical arms of the trials. Four of the nine trials reported the results of 18 F-fluorodopa PET scans, indicating no improvements of dopaminergic nigrostriatal neurones following sham surgery. Therefore, while the initial randomised trials relying on the use of sham operated controls were justified on methodological grounds, we suggest that the analysis of the evidence generated by the completed and published trials indicates that placebo controlled trials are not necessary to advance and evaluate the safety and efficacy of emerging regenerative therapies for PD.

Management of hypertension and renin-angiotensin-aldosterone system blockade in adults with diabetic kidney disease: Association of British Clinical Diabetologists and the Renal Association UK guideline update 2021

People with type 1 and type 2 diabetes are at risk of developing progressive chronic kidney disease (CKD) and end-stage kidney failure. Hypertension is a major, reversible risk factor in people with diabetes for development of albuminuria, impaired kidney function, end-stage kidney disease and cardiovascular disease. Blood pressure control has been shown to be beneficial in people with diabetes in slowing progression of kidney disease and reducing cardiovascular events. However, randomised controlled trial evidence differs in type 1 and type 2 diabetes and different stages of CKD in terms of target blood pressure. Activation of the renin-angiotensin-aldosterone system (RAAS) is an important mechanism for the development and progression of CKD and cardiovascular disease. Randomised trials demonstrate that RAAS blockade is effective in preventing/ slowing progression of CKD and reducing cardiovascular events in people with type 1 and type 2 diabetes, albeit differently according to the stage of CKD. Emerging therapy with sodium glucose cotransporter-2 (SGLT-2) inhibitors, non-steroidal selective mineralocorticoid antagonists and endothelin-A receptor antagonists have been shown in randomised trials to lower blood pressure and further reduce the risk of progression of CKD and cardiovascular disease in people with type 2 diabetes. This guideline reviews the current evidence and makes recommendations about blood pressure control and the use of RAAS-blocking agents in different stages of CKD in people with both type 1 and type 2 diabetes.

Ketamine for the treatment of mental health and substance use disorders: comprehensive systematic review

Background In the past two decades, subanaesthetic doses of ketamine have been demonstrated to have rapid and sustained antidepressant effects, and accumulating research has demonstrated ketamine's therapeutic effects for a range of psychiatric conditions. Aims In light of these findings surrounding ketamine's psychotherapeutic potential, we systematically review the extant evidence on ketamine's effects in treating mental health disorders. Method The systematic review protocol was registered in PROSPERO (identifier CRD42019130636). Human studies investigating the therapeutic effects of ketamine in the treatment of mental health disorders were included. Because of the extensive research in depression, bipolar disorder and suicidal ideation, only systematic reviews and meta-analyses were included. We searched Medline and PsycINFO on 21 October 2020. Risk-of-bias analysis was assessed with the Cochrane Risk of Bias tools and A Measurement Tool to Assess Systematic Reviews (AMSTAR) Checklist. Results We included 83 published reports in the final review: 33 systematic reviews, 29 randomised controlled trials, two randomised trials without placebo, three non-randomised trials with controls, six open-label trials and ten retrospective reviews. The results were presented via narrative synthesis. Conclusions Systematic reviews and meta-analyses provide support for robust, rapid and transient antidepressant and anti-suicidal effects of ketamine. Evidence for other indications is less robust, but suggests similarly positive and short-lived effects. The conclusions should be interpreted with caution because of the high risk of bias of included studies. Optimal dosing, modes of administration and the most effective forms of adjunctive psychotherapeutic support should be examined further.

Tolerating bad health research: the continuing scandal

BackgroundAt the 2015 REWARD/EQUATOR conference on research waste, the late Doug Altman revealed that his only regret about his 1994 BMJ paper ‘The scandal of poor medical research’ was that he used the word ‘poor’ rather than ‘bad’. But how much research is bad? And what would improve things?Main textWe focus on randomised trials and look at scale, participants and cost. We randomly selected up to two quantitative intervention reviews published by all clinical Cochrane Review Groups between May 2020 and April 2021. Data including risk of bias, number of participants, intervention type and country were extracted for all trials included in selected reviews. High risk of bias trials were classed as bad. The cost of high risk of bias trials was estimated using published estimates of trial cost per-participant.We identified 96 reviews authored by 546 reviewers from 49 clinical Cochrane Review Groups that included 1,659 trials done in 84 countries. Of the 1,640 trials providing risk of bias information, 1,013 (62%) were high risk of bias (bad), 494 (30%) unclear and 133 (8%) low risk of bias. Bad trials were spread across all clinical areas and all countries. Well over 220,000 participants (or 56% of all participants) were in bad trials. The low estimate of the cost of bad trials was £726 million; our high estimate was over £8 billion. We have five recommendations: trials should be neither funded (1) or given ethical approval (2) unless they have a statistician and methodologist; trialists should use a risk of bias tool at design (3); more statisticians and methodologists should be trained and supported (4); there should be more funding into applied methodology research and infrastructure (5). ConclusionsMost randomised trials are bad and most trial participants will be in one. The research community has tolerated this for decades. This has to stop: we need to put rigour and methodology where it belongs– at the centre of our science.

Does reading a book in bed make a difference to sleep in comparison to not reading a book in bed? The People’s Trial—an online, pragmatic, randomised trial

Background The best way of comparing healthcare treatments is through a randomised trial. In a randomised trial, we compare something (a treatment or intervention) to something else, often another treatment. Who gets what is decided at random, meaning everyone has an equal chance of getting any of the treatments. This means any differences found can be put down to the treatment received rather than other things, such as where people live, or health conditions they might have. The People’s Trial aimed to help the public better understand randomised trials by inviting them to design and carry out a trial. The question chosen by the public for The People’s Trial was: ‘Does reading a book in bed make a difference to sleep, in comparison to not reading a book in bed?’ This paper describes that trial, called ‘The Reading Trial’. Methods The Reading Trial was an online, randomised trial. Members of the public were invited to take part through social media campaigns. People were asked to either read a book in bed before going to sleep (intervention group) or not read a book in bed before going to sleep (control group). We asked everyone to do this for 7 days, after which they measured their sleep quality. Results During December 2019, a total of 991 people took part in The Reading Trial, half (496 (50%)) in the intervention group and half (495 (50%)) in the control group. Not everyone finished the trial: 127 (25.6%) people in the intervention group and 90 (18.18%) people in the control group. Of those providing data, 156/369 (42%) people in the intervention group felt their sleep improved, compared to 112/405 (28%) of those in the control group, a difference of 14%. When we consider how certain we are of this finding, we estimate that, in The Reading Trial, sleep improved for between 8 and 22% more people in the intervention group compared to the control group. Conclusions Reading a book in bed before going to sleep improved sleep quality, compared to not reading a book in bed. Trial registration ClinicalTrials.gov NCT04185818. Registered on 4 December 2019.

Protocol: Benefits and harms of remdesivir for COVID-19 in adults: A systematic review with meta-analysis

Background Effective drug treatments for Covid-19 are needed to decrease morbidity and mortality for the individual and to alleviate pressure on health care systems. Remdesivir showed promising results in early randomised trials but subsequently a large publicly funded trial has shown less favourable results and the evidence is interpreted differently in clinical guidelines. Systematic reviews of remdesivir have been published, but none have systematically searched for unpublished data, including regulatory documents, and assessed the risk of bias due to missing evidence. Methods We will conduct a systematic review of randomised trials comparing remdesivir to placebo or standard of care in any setting. We will include trials regardless of the severity of disease and we will include trials examining remdesivir for indications other than Covid-19 for harms analyses. We will search websites of regulatory agencies, trial registries, bibliographic databases, preprint servers and contact trial sponsors to obtain all available data, including unpublished clinical data, for all eligible trials. Our primary outcomes will be all-cause mortality and serious adverse events. Our secondary outcomes will be length of hospital stay, time to death, severe disease, and adverse events. We will assess the risk of bias using the Cochranes Risk of Bias 2 tool and the risk of bias due to missing evidence (e.g. publication bias, selective reporting bias) using the ROB-ME tool. Where appropriate we will synthesise study results by conducting random-effects meta-analysis. We will present our findings in a Summary of Findings table and rate the certainty of the evidence using the GRADE approach. Discussion By conducting a comprehensive systematic review including unpublished data (where available), we expect to be able to provide valuable information for patients and clinicians about the benefits and harms of remdesivir for the treatment of Covid-19. This will help to ensure optimal treatment for individual patients and optimal utilisation of health care resources. Systematic review registration CRD42021255915.