Giving and taking: ethical treatment assignment in controlled trials.

The current version of the Declaration of Helsinki states that 'the benefits, risks, burdens and effectiveness of a new intervention must be tested against those of the best current proven intervention(s) … '. This wording implies that it is acceptable for patients to be assigned to receive an unproven new intervention and to be denied a best current proven intervention. We assert that patients being invited to participate in controlled trials cannot, ethically, be expected to forego proven beneficial forms of care. Patients being treated in controlled trials should not knowingly be disadvantaged compared with similar patients being treated in usual clinical care, where they have access to beneficial care. In this article, we have tried to separate for discussion 'the withholding of effective care from trial participants', 'informed consent to treatment', 'blinding' and 'use of placebos'.

Nocebo and lessebo effects.

The power of placebos is commonly associated with the placebo effect. In contrast, detrimental effects related to the use of a placebo are little studied and less well recognized. This chapter covers the nocebo and lessebo effects defined, respectively, as expectation of harm in the form of adverse events in a placebo arm and reduction of therapeutic benefit due to the uncertainty of being allocated to placebo. The lessebo effect is a more recent concept and has been described only in depression, schizophrenia and Parkinson's disease. The nocebo response was evaluated in many neurological diseases, including epilepsy, multiple sclerosis, Parkinson's disease, Alzheimer's disease, restless leg syndrome, among others. Meta-analyses of randomized controlled trials in these conditions reveal a significant variability of the magnitude of the nocebo response and that factors related to study design, study participants or neurological disease can be associated with a nocebo response, although with the opposing findings across conditions. The knowledge about neurobiological mechanisms of the nocebo effect is poor for neurological diseases, and most of the information has been generated in pain. Functional neuroimaging suggests the existence of a distinct network for the anticipation and the experience of a hyperalgesia nocebo response. Different types of neurotransmitters have been involved, including cholecystokinin, dopamine and opioids. Recognizing the potential impact of nocebo and lessebo effects, mitigating strategies are in development with application to clinical research and clinical practice, such as a contextualized informed consent process, alternative study designs and enhancement of patient-physician communication.

Strategies to minimize placebo effects in research investigations.

Placebo-controlled trials are the research standard to evaluate new interventions for which there is no standard of care. While lessening performance and detection bias, such design provides a direct mode of comparison against the probed intervention. Still, using placebo arms may pose new challenges to the design, conduct and analysis of clinical trials. This is particularly relevant in circumstances of non-additivity between the therapeutic and the placebo effects, if the outcome of interest has floor or ceiling effects, or when the predicted effect size of the intervention is large and leads to small sample sizes. There are several possible strategies to mitigate the confounding effects of the placebo, each relevant to specific clinical trial designs. This chapter puts into context the new challenges created by the placebo effect, discusses possible ways around them, and explores the future of the field.

Systematic review with meta-analysis: the efficacy of tranexamic acid in upper gastrointestinal bleeding.

BACKGROUND: Upper gastrointestinal bleeding is a common medical emergency associated with substantial mortality. Tranexamic acid may be effective for reducing mortality in upper gastrointestinal bleeding. AIM: To examine the effects of tranexamic acid in upper gastrointestinal bleeding by systematic review and meta-analysis. METHODS: We searched PubMed, EMBASE, CINAHL, the Cochrane Central Register of Controlled Trials (CENTRAL) and other relevant websites for randomised controlled trials investigating the effect of tranexamic acid published from inception to December 10, 2019. The primary outcome of interest was mortality. Estimates of effect were pooled with a random effects model. Quality of evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluations (GRADE) approach. RESULTS: The search identified 1572 citations. Eleven trials comprising 2076 patients were eligible for inclusion. Of these, 10 trials (2013 patients) compared tranexamic acid with placebo. Risk of death was significantly reduced in patients who received tranexamic acid compared with those who received placebo (RR 0.59, 95% CI 0.43-0.82, P = 0.001) with no significant heterogeneity noted among studies (I2  = 0%, P = 0.81). The GRADE assessment rated the quality of the evidence for mortality as moderate due to risk of bias. There were no statistically significant differences between tranexamic acid and placebo for the prevention of re-bleeding, need for surgical interventions, need for blood transfusions or frequency of thromboembolic events. CONCLUSIONS: Moderate-quality evidence shows that tranexamic acid is superior to placebo for the reduction in mortality in patients with upper gastrointestinal bleeding. While our findings lend further support to the use of tranexamic acid for treating patients with upper gastrointestinal bleeding, additional higher-quality trials are needed.

Placebo-To be or not to be? Are there really alternatives to placebo-controlled trials?

Recent success of established treatment has driven concerns about the ethics of using placebo-controlled trials in psychiatry. Active-controlled (superiority or non-inferiority) trials do not include a placebo-arm and thus avoid the associated ethical concerns but show disadvantages in other respects. The aim of this paper is to review the available literature and critically discuss the evidence regarding the use of placebo-controlled- versus active-controlled trials. A MEDLINE/PubMed and Google Scholar search was performed. Studies included focused on the deliberation on placebo-controlled- versus active-controlled trials. Twenty-six studies were included. The most cited benefits of placebo-controlled trials were greater scientific reliability of the results and no average impact on patients' health. Disadvantages were mainly related to withholding effective treatment and limited generalizability. The most frequent argument in favor of active-controlled trials is the lower chance of receiving ineffective medication during the trial. Downsides include larger sample sizes, higher costs and lower scientific reliability of results. Most authors agree that all trial designs are relevant to psychiatric research depending on study goals. Whatsoever, data does not support forgoing placebo-controlled trials. Expert consensus is warranted to permit drawing conclusions on the debate on the relevance of placebo-controlled trials.

Systematic review of controlled clinical studies using umbilical cord blood for regenerative therapy: Identifying barriers to assessing efficacy.

Clinical use of umbilical cord blood (UCB) for novel indications in regenerative therapy continues to rise, however, whether new indications are proven is less clear. An updated systematic search of the literature, focusing only on controlled clinical studies, is needed to properly assess potential efficacy. After updating our systematic search to April 1, 2018 (PROSPERO protocol CRD42016040157), a total of 16 studies were identified that addressed the treatment of cerebral palsy (four studies), type 1 diabetes (three studies), and nine other novel potential indications where only a single controlled study was identified. In the four controlled studies of patients with cerebral palsy, three used allogeneic cells and reported greater improvement in motor-related scores at 1, 3 and 6 months compared with controls. The results were mixed for other scores at other time points, including additional measures of mental and motor function. One study of autologous UCB treatment reported an improvement in motor function scores at 12 months compared with controls. In the three controlled studies of type 1 diabetes, two studies used autologous cells whereas one used allogeneic cord blood cells to "educate" autologous lymphocytes. Taken together, there was no clear difference in HbA1c levels or daily insulin requirements between treated patients and controls. For the nine published reports with a single controlled study, eight used allogeneic UCB cells and seven infused mesenchymal stromal cells derived from UCB. All but one study reported benefit. Many other published reports that lack a control group were not included in our analysis. More controlled studies are needed that use similar approaches regarding cell source and outcome measures at similar time points. Pooled estimates of results from multiple studies will be essential as published studies remain modest in size. Patients should continue to be enrolled in clinical trials because there are no novel potential indications remain unproven.

Análisis crítico de un ensayo clínico de no-inferioridad / Critical analysis of a noninferiority trial

In the era of diseases with highly efficacious treatments, the publication of randomized noninferiority clinical trials is increasingly frequent. However, users of medical literature are less familiar with this type of studies. The aim of this article is to give an introduction to the critical assessment of noninferiority clinical trials, through the solving of a therapeutic dilemma, which will be addressed through the analysis of a recently published trial of this type.

[Ensayos clínicos publicados en el Boletín Médico del Hospital Infantil de México: un análisis crítico]. / Clinical trials published in the Boletín Médico del Hospital Infantil de México: a critical analysis.

Introducción: El ensayo clínico es la manera más rigurosa de conducir los experimentos en seres humanos. Desde su introducción en investigación biomédica se han implementado cambios en el modo de establecer las bases para el diagnóstico, pronóstico y la terapéutica en la práctica clínica. Se han realizado estudios para identificar los ensayos clínicos publicados en diferentes áreas médicas, pero hasta el momento ninguno había identificado los ensayos clínicos publicados en el Boletín Médico del Hospital Infantil de México (BMHIM). El objetivo de este trabajo fue identificar y describir los ensayos clínicos controlados (ECC) publicados en el BMHIM. Métodos: Se realizó búsqueda manual y sistemática en cada uno de los números y volúmenes del BMHIM de 1968 a 2016. Se registraron los ECC para obtener sus principales características. Adicionalmente, se evaluó su calidad metodológica mediante la herramienta de riesgo de sesgo. Los resultados se presentan de forma descriptiva, gráfica y temporal. Resultados: Se revisaron 73 números con 363 volúmenes, analizando 4925 artículos. La proporción de ECC identificados en el BMHIM fue del 1% (67/4925). En general, los ensayos clínicos se realizaron en el contexto nacional, en el tercer nivel de atención, con un tamaño de muestra reducido, y las intervenciones farmacológicas fueron las más utilizadas. La calidad metodológica de los estudios fue baja, con alto riesgo de sesgo. Conclusiones: Los ensayos clínicos representan el 1% de todos los artículos de investigación originales publicados en el BMHIM. Aún existen áreas de investigación pediátrica, las cuales requieren del desarrollo de ECC para mejorar la práctica clínica, así como para elevar la calidad de la investigación. Background: Controlled clinical trials (CCT) are the study design with the highest accuracy and evidence level. From its introduction in biomedical research, changes have been implemented in the way of establishing the basis for diagnosis, prognosis and treatment in clinical practice. Studies to identify published CCTs regarding different medical fields have been carried out. To date, none of them has identified the clinical trials that have been published in the Boletín Médico del Hospital Infantil de México (BMHIM). The aim of this study was to identify and describe the controlled clinical trials published in the BMHIM. Methods: A manual and systematic search was performed in each of the volumes of the BMHIM from 1968 to 2016. CCTs were recorded to obtain their main characteristics. Additionally, their methodological quality was assessed through the "risk of bias" tool. Results are presented in a descriptive, graphic and time-based manner. Results: In total, 73 issues with 363 volumes were reviewed, and 4925 articles were analyzed. The proportion of CCTs identified in the BMHIM was 1% (67/4925). In general, clinical trials were performed in the national context and in the third-level of medical care. CCTs also presented reduced sample sizes; pharmacological interventions were the most frequent. The methodological quality of the studies was low with a high risk of bias. Conclusions: Clinical trials represented 1% of all the original research articles published in the BMHIM. There are still pediatric research fields that require CCTs to be developed in order to improve clinical practice, as well as to increase the quality of the research.

Ensayos clínicos publicados en el Boletín Médico del Hospital Infantil de México: un análisis crítico / Clinical trials published in the Boletín Médico del Hospital Infantil de México: a critical analysis

Resumen Introducción: El ensayo clínico es la manera más rigurosa de conducir los experimentos en seres humanos. Desde su introducción en investigación biomédica se han implementado cambios en el modo de establecer las bases para el diagnóstico, pronóstico y la terapéutica en la práctica clínica. Se han realizado estudios para identificar los ensayos clínicos publicados en diferentes áreas médicas, pero hasta el momento ninguno había identificado los ensayos clínicos publicados en el Boletín Médico del Hospital Infantil de México (BMHIM). El objetivo de este trabajo fue identificar y describir los ensayos clínicos controlados (ECC) publicados en el BMHIM. Métodos: Se realizó búsqueda manual y sistemática en cada uno de los números y volúmenes del BMHIM de 1968 a 2016. Se registraron los ECC para obtener sus principales características. Adicionalmente, se evaluó su calidad metodológica mediante la herramienta de riesgo de sesgo. Los resultados se presentan de forma descriptiva, gráfica y temporal. Resultados: Se revisaron 73 números con 363 volúmenes, analizando 4925 artículos. La proporción de ECC identificados en el BMHIM fue del 1% (67/4925). En general, los ensayos clínicos se realizaron en el contexto nacional, en el tercer nivel de atención, con un tamaño de muestra reducido, y las intervenciones farmacológicas fueron las más utilizadas. La calidad metodológica de los estudios fue baja, con alto riesgo de sesgo. Conclusiones: Los ensayos clínicos representan el 1% de todos los artículos de investigación originales publicados en el BMHIM. Aún existen áreas de investigación pediátrica, las cuales requieren del desarrollo de ECC para mejorar la práctica clínica, así como para elevar la calidad de la investigación.

Abstract Background: Controlled clinical trials (CCT) are the study design with the highest accuracy and evidence level. From its introduction in biomedical research, changes have been implemented in the way of establishing the basis for diagnosis, prognosis and treatment in clinical practice. Studies to identify published CCTs regarding different medical fields have been carried out. To date, none of them has identified the clinical trials that have been published in the Boletín Médico del Hospital Infantil de México (BMHIM). The aim of this study was to identify and describe the controlled clinical trials published in the BMHIM. Methods: A manual and systematic search was performed in each of the volumes of the BMHIM from 1968 to 2016. CCTs were recorded to obtain their main characteristics. Additionally, their methodological quality was assessed through the "risk of bias" tool. Results are presented in a descriptive, graphic and time-based manner. Results: In total, 73 issues with 363 volumes were reviewed, and 4925 articles were analyzed. The proportion of CCTs identified in the BMHIM was 1% (67/4925). In general, clinical trials were performed in the national context and in the third-level of medical care. CCTs also presented reduced sample sizes; pharmacological interventions were the most frequent. The methodological quality of the studies was low with a high risk of bias. Conclusions: Clinical trials represented 1% of all the original research articles published in the BMHIM. There are still pediatric research fields that require CCTs to be developed in order to improve clinical practice, as well as to increase the quality of the research.

Guidelines of the International Headache Society for controlled trials of preventive treatment of chronic migraine in adults.

Background Quality clinical trials form an essential part of the evidence base for the treatment of headache disorders. In 1991, the International Headache Society Clinical Trials Standing Committee developed and published the first edition of the Guidelines for Controlled Trials of Drugs in Migraine. In 2008, the Committee published the first specific guidelines on chronic migraine. Subsequent advances in drug, device, and biologicals development, as well as novel trial designs, have created a need for a revision of the chronic migraine guidelines. Objective The present update is intended to optimize the design of controlled trials of preventive treatment of chronic migraine in adults, and its recommendations do not apply to trials in children or adolescents.

The History of the Salt Wars.

The "Salt-Blood Pressure Hypothesis" states that an increase in the intake of salt leads to an increased in blood pressure and subsequently increases the risk for cardiovascular events, which has been a point of contention for decades. This article covers the history and some of the key players pertaining to "The Salt Wars" during the first half of the 1900s, both in Europe and in the United States. Early studies finding benefits with salt restriction in those with hypertension were based on uncontrolled case reports. The overall evidence in the first half of the 1900s suggests that a low-salt diet was not a reasonable strategy for treating hypertension.