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

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.

Pautas de chequeo, parte IV: STARD y CARE / Checklists, part IV: STARD and CARE

Los ensayos clínicos controlados representan el diseño más destacado en la investigación biomédica. Sin embargo, existen otros diseños metodológicos que aportan información relevante para la medicina basada en la evidencia: los estudios sobre precisión de pruebas diagnósticas y reportes de caso. Al igual que con otros diseños, estos necesitan cumplir con estándares de calidad en su reporte, para lo que se han diseñados las pautas STARD y CARE, respectivamente. La pauta STARD comenzó a desarrollarse en 1999, siendo publicada en 2003, e incluye 25 ítems agrupados en 5 dominios (título/resumen/palabras clave, introducción, métodos, resultados, discusión). La pauta CARE se elaboró de acuerdo a la Guía para Desarrolladores de Guías de Reporte de Investigación en Salud, siendo publicada en 2013, e incluye 13 ítems, sin dominios declarados y que es de uso general para todos los ámbitos de la medicina. Así como con otras pautas de chequeo, el uso de STARD se ha asociado a una mejora en la calidad del reporte de estudios sobre precisión diagnóstica. En el caso de CARE, es necesario evaluar con el paso de los años su impacto en la calidad de los reportes de caso. Este último artículo de la serie describe ambas pautas de chequeo para su uso por parte de los autores de la REVISTA CHILENA DE CIRUGÍA, con el fin de lograr una mejora de sus artículos de una forma simple y eficiente.

Controlled clinical trials represent the design highlight in biomedical research. However, there are other methodological designs that provide relevant information for evidence-based medicine: studies of diagnostic test accuracy and case reports. As with other designs, they need to meet quality standards in their reporting, that is the reason for the design of STARD and CARE checklists, respectively. The STARD checklist began to develop in 1999, being published in 2003, it includes 25 items grouped into five domains (title / abstract / keywords, introduction, methods, results, discussion). The CARE checklist was made according to the Guidance for Developers of Health Research Reporting Guidelines, was published in 2013, it includes 13 items, without declared domains and is commonly used for all areas of medicine. As with other checklist, the use of STARD has been associated with an improvement in quality report of studies on diagnostic accuracy. In the case of CARE, it is necessary to assess over the years its impact on quality of case reports. This last article in the series describes both checklists for use by the authors of the REVISTA CHILENA DE CIRUGÍA, in order to achieve an improvement in their articles in a simple and efficient way.

Chemonucleolysis in lumbar disc herniation: a meta-analysis

PURPOSE: To carry out a systematic review and meta-analysis of the efficacy of chemonucleolysis in the treatment of lumbar disc herniation. METHODS: Clinical trials were selected from 3 electronic databases (The Cochrane Controlled Trials Register, MEDLINE, and EMBASE). Data were analyzed with the software STATA, using the meta command. RESULTS: Twenty-two clinical trials were eligible. For chemonucleolysis versus placebo, the summary risk ratio estimate for pain relief as outcome was 1.51 (95 percent CI: 1.27-1.80). The summary estimate was 1.07 (95 percent CI: 0.95-1.20) for the comparison between chymopapain and collagenase. Regarding chemonucleolysis with chymopapain versus surgery, the fixed-effect summary estimate of effect for pain relief was 0.93 (95 percent CI: 0.88-0.98) with surgery as the reference group. In this case, heterogeneity was statistically significant. CONCLUSIONS: Chemonucleolysis with chymopapain was superior to placebo and was as effective as collagenase in the treatment of lumbar disc prolapse. Results for studies comparing chemonucleolysis with surgery were heterogeneous, making it difficult to interpret the summary measure of effect.

OBJETIVO: Avaliar a eficácia da quimonucleólise no tratamento da hérnia de disco lombar por meio de uma metanálise de ensaios clínicos. MÉTODOS: Os ensaios clínicos foram selecionados de três bases de dados eletrônicas( Cochrane, MEDLINE, e EMBASE). Os dados foram analisados por intermédio do aplicativo STATA, com o comando meta. RESULTADOS: trabalhamos com 22 ensaios clínicos. Para a comparação entre quimonucleólise e placebo, a estimativa da razão de riscos, tendo melhora da dor como desfecho, foi de 1,51 (I 95 por cento C: 1,27-1,80). Aquela medida foi de 1,07 (I 95 por cento C: 0,95-1,20) para a comparação entre quimopapaína e colagenase. Em um modelo de efeitos fixos, a razão de risco, para melhora da dor, foi 0,93 (I 95 por cento C: 0,88-0,98), tendo a discectomia como grupo de referência. Nesse caso, um teste de heterogeneidade foi considerado estatisticamente significante. CONCLUSÕES: a eficácia da quimonucleólise foi superior à do placebo e semelhante à da colagenase. Os resultados dos estudos referentes à comparação entre quimonucleólise e cirurgia foram heterogêneos, o que implica interpretação não-trivial da medida de efeito.