Réplica a "Espironolactona en pacientes con insuficiencia cardiaca y fracción de eyección preservada" / Reply to "Spironolactone in patients with heart failure and preserved ejection fraction"

No disponible

Risk of bias assessment of clinical trials published in iberoamerican urological journals / Evaluación del riesgo de sesgo en los ensayos clínicos publicados en revistas urológicas iberoamericanas

OBJECTIVES: To assess the risk of bias of clinical trials published in iberoamerican indexed journals from January 1, 2008 to December 31, 2012. METHODS: We performed a descriptive study based on the clinical trials published from January 1st 2008 to December 31st 2012 in the iberoamerican urological journals. We assessed the risk of bias by the Cochrane tool. We used descriptive statistics in Stata 13 and Revman 5.2 to create the risk of bias graphs within and across studies. RESULTS: We identified 41 clinical trials: 21 trials in the International Brazilian Journal of Urology, seven trials in Actas Urológicas Españolas, six trials in Archivos Españoles de Urología, two trials in the Boletin Mexicano de Urología, four trials in Revista Mexicana de Urología and one trial in Revista Urología Colombiana. Most of these trials had unclear risk for the generation of the randomization (selection bias), the allocation concealment (selection bias) and the blinding (performance and detection). There was low risk of bias for incomplete results data (Attrition bias) and selective notification (notification bias). High risk of bias was found in other possible sources of bias, mainly because of low sample size. CONCLUSIONS: Based on the Cochrane risk of bias tool assessment, most of the published trials do not accomplish an adequate description of the methods. We should also be aware that most of the trials lack an adequate sample size calculation that limits the power of these trials. We recommend better description of the methods for randomization, and increasing the sample size to improve the quality of the trials published in urologic iberoamerican journals

OBJETIVO: Evaluar el riesgo de sesgo en los ensayos clínicos publicados en revistas iberoamericanas indexadas desde el 1 de enero del 2008 al 31 de Diciembre del 2012. MÉTODOS: Realizamos un estudio descriptivo basado en los ensayos clínicos publicados en las revistas urológicas iberoamericanas desde el 1 de Enero del 2008 y el 31 de diciembre del 2012. Evaluamos el riesgo de sesgo mediante la herramienta Cochrane. Utilizamos estadísticas descriptivas en Stata 13 y Revman 5.2 para crear gráficas del riesgo de sesgo dentro de los estudios y entre ellos. RESULTADOS: Identificamos 41 ensayos clínicos: 21 ensayos en el International Brazilian Journal of Urology, siete ensayos en Actas Urólogicas Españolas, seis ensayos en Archivos Españoles de Urología, dos en el Boletín Mexicano de Urología, cuatro en la Revista Mexicana de Urología y un ensayo en la Revista Urología colombiana. La mayoría de estos ensayos presentan un riesgo confuso para la generación de la aleatorización (sesgo de selección), la ocultación de la asignación (sesgo de selección) y el enmascaramiento (ejecución y detección). Había un bajo riesgo de sesgo para datos de resultados incompletos (sesgo de abandono) y de notificación selectiva (sesgo de notificación). El alto riesgo de sesgo se encontró en otras posibles fuentes de sesgo, principalmente debido a tamaño muestral bajo. CONCLUSIONES: Basándose en la herramienta Cochrane de evaluación del riesgo de sesgo, la mayoría de los ensayos publicados no llevan a cabo una adecuada descripción de los métodos. También debemos ser conscientes de que la mayoría de los ensayos carecen de un cálculo del tamaño muestral adecuado lo que limita su poder. Recomendamos una mejor descripción de los métodos de asignación aleatoria y aumentar el tamaño muestral para mejorar la calidad de los ensayos publicados en las revistas urológicas iberoamericanas

Inadequate use and regulation of interventions against publication bias decreases their effectiveness: a systematic review.

OBJECTIVES: To determine the effectiveness of interventions designed to prevent or reduce publication and related biases. STUDY DESIGN AND SETTING: We searched multiple databases and performed manual searches using terms related to publication bias and known interventions against publication bias. We dually reviewed citations and assessed risk of bias. We synthesized results by intervention and outcomes measured and graded the quality of the evidence (QoE). RESULTS: We located 38 eligible studies. The use of prospective trial registries (PTR) has increased since 2005 (seven studies, moderate QoE); however, positive outcome-reporting bias is prevalent (14 studies, low QoE), and information in nonmandatory fields is vague (10 studies, low QoE). Disclosure of financial conflict of interest (CoI) is inadequate (five studies, low QoE). Blinding peer reviewers may reduce geographical bias (two studies, very low QoE), and open-access publishing does not discriminate against authors from low-income countries (two studies, very low QoE). CONCLUSION: The use of PTR and CoI disclosures is increasing; however, the adequacy of their use requires improvement. The effect of open-access publication and blinding of peer reviewers on publication bias is unclear, as is the effect of other interventions such as electronic publication and authors' rights to publish their results.

Lectura crítica de la literatura biomédica (I): cómo valorar el riesgo de sesgo de un estudio / Critical appraisal of the biomedical literature (I): how to evaluate the risk of bias in a study

El ejercicio de una práctica clínica basada en la evidencia exige unas competencias básicas para valorar e interpretar la literatura biomédica. En este artículo se revisan los puntos críticos para determinar la validez de los resultados de un ensayo clínico, circunscribiéndonos al ensayo ACOSOG-Z0011 (AU)

Clinicians interested in evidence-based clinical practice need some basic competencies in critical appraisal of the medical literature. In this article we review the key points that determine the validity of the results of a specific clinical trial: the ACOSOG-Z0011 study (AU)

Evaluación del efecto de los tratamientos utilizando comparaciones indirectas. Respuesta / Evaluation of comparative treatment effects using indirect comparisons. Response

No disponible

The money blind: how to stop industry bias in biomedical science, without violating the First Amendment.

The pharmaceutical and medical device industries use billions of dollars to support the biomedical science that physicians, regulators, and patients use to make healthcare decisions--the decisions that drive an increasingly large portion of the American economy. Compelling evidence suggests that this industry money buys favorable results, biasing the outcomes of scientific research. Current efforts to manage the problem, including disclosure mandates and peer reviews, are ineffective. A blinding mechanism, operating through an intermediary such as the National Institutes of Health, could instead be developed to allow industry support of science without allowing undue influence. If the editors of biomedical journals fail to mandate that industry funders utilize such a solution, the federal government has several regulatory levers available, including conditioning federal funding and direct regulation, both of which could be done without violating the First Amendment.

[Clinical trials registers. Introduction to the topic and backgrounds]. / Register für klinische Studien. Einführung in das Thema und Hintergründe.

It is a moral responsibility of those performing clinical studies towards patients, funding organizations, the scientific community and towards the general public to publish the results of clinical trials. Under-reporting of clinical trials with null or even negative results as well as over-reporting of trials with positive results can lead to a biased assessment of (new) treatments, which leads to overestimation of potential benefits and underestimation of potential risks. Comprehensive, publicly accessible clinical trial registries are now widely accepted as an essential tool to fill the information gap. Here, the background for implementing a clinical trials register in Germany is described, whereby publication bias, in particular, is addressed.

The federal government and academic texts as barriers to informed consent.

Informed patient consent for medical treatment is required by both law and medical ethics. Yet, both federal agencies and academicians are participating in the suppression of information about the heightened risk of breast cancer posed by oral contraceptives and induced abortion. There is historical precedent in the long-delayed acknowledgement of the smoking/lung cancer link. By law, a patient has the right to be fully informed of the nature of her medical condition and any proposed course of therapy. It is assumed that a patient will be given the complete and true scientific basis of her diagnosis and treatment, to ensure that her well-being and her autonomy in decision-making are protected. Informed consent is the process by which a patient can participate in choices about medical treatment. It originates from the legal and ethical right of the patient to direct what is done to her body, and from the ethical duty of the physician to involve the patient in her medical care. Our federal government has become a barrier to informed consent concerning oral contraceptive drugs and induced abortion.

Sesgos y dificultades en la investigación de los nuevos antipsicóticos / No disponible

En este trabajo se pone de manifiesto lo limitados y poco generalizables que son los ensayos clínicos controlados aleatorizados con fármacos debido a errores y dificultades de diseño, análisis e interpretación de resultados, los confiltos éticos que plantean y lo sesgada que es la información que nos llega a través de ls revistas científicas, todo ello ejemplificado con los nuevos antipsicóticos(AU)

We describe the limitation sof randomised clinical trials of drugs because of pifalls in methodological design, analysis and interpretation of results, ethical confilcts and publication bias. We analyse trials on new antipsychotics as example of these pitfalls and limitations(AU)