Risk of bias in dentistry-related randomized controlled trials in spanish language journals

Objectives: To assess the risk of bias (RoB) of randomized controlled trials (RCTs) published in dental journals in the Spanish language. Methods: A systematic retrospective survey was conducted of all RCTs published from 1980 to 2019 in dentistry Spanish and Latin American journals. We extracted data and performed RoB assessments using the Cochrane Risk of Bias tool. Results: 292 RCTs published in 51 journals were included. The best-rated domains were incomplete outcome data, selective reporting, and other biases. The domains assessed with higher proportions of an unclear or high risk of bias were sequence generation, allocation concealment, and blinding of outcome assessment. There is a low proportion of RCTs published in Spanish language journals. However, the number has been increasing over the years, and the low risk of bias assessment rates across domains show an increasing trend. Conclusions: A low percentage of Spanish-language dental journals issue RCTs. Our assessment of these RCTs' RoB suggests higher difficulties in the design and conduction phase than in the posterior reporting stage.

Systematic Reviews and Meta-Analysis: A Guide for Beginners

Systematic reviews involve the application of scientific methods to reduce bias in review of literature. The key components of a systematic review are a well-defined research question, comprehensive literature search to identify all studies that potentially address the question, systematic assembly of the studies that answer the question, critical appraisal of the methodological quality of the included studies, data extraction and analysis (with and without statistics), and considerations towards applicability of the evidence generated in a systematic review. These key features can be remembered as six ‘A’; Ask, Access, Assimilate, Appraise, Analyze and Apply. Meta-analysis is a statistical tool that provides pooled estimates of effect from the data extracted from individual studies in the systematic review. The graphical output of meta-analysis is a forest plot which provides information on individual studies and the pooled effect. Systematic reviews of literature can be undertaken for all types of questions, and all types of study designs. This article highlights the key features of systematic reviews, and is designed to help readers understand and interpret them. It can also help to serve as a beginner’s guide for both users and producers of systematic reviews and to appreciate some of the methodological issues.

Efficacy and safety of Di-Tan Decoction for treating post-stroke neurological disorders: a systematic review and Meta-analysis of randomized clinical trials / 中国天然药物

The management of post-stroke complications plays an important role in the quality of life. Di-Tan Decoction (DTD; ) is a widely used traditional Chinese medicine. This study incorporated systematic review and meta-analysis to evaluate the efficacy of DTD in post-stroke neurological disorders. Randomized clinical trials (RCTs) were searched from English, Chinese and Korean electronic medical databases, by including the keywords "Di-Tan Tang", "Di-Tan Decoction", "Scour Phlegm Decoction", "stroke", and "RCT. Each RCT included control (placebo, conventional therapy, or Western medicine) and experimental (DTD treatment) groups. For patients inflicted with stroke for 1-6 weeks, the outcomes of post-stroke neurological disorders were measured by scales for post-stroke symptoms and were classified as "completely healed", "markedly effective", "effective" and "ineffective". Totally, 11 RCTs (n = 490 controls and n = 502 DTD subjects) were selected from 210 articles identified in the initial search. A meta-analysis of evaluation criteria in post-stroke symptoms revealed that the overall odds ratio (ORs) for alleviating post-stroke neurological disorders were 0.30-fold lower (95% CI = 0.21-0.43) in the DTD group than the control (Western medicine) group (P < 0.000 01). Moreover, regardless of the type of stroke diagnostic scale applied (including NFA, HDS, and NIHSS), the overall post-stroke symptoms determined were less severe in the DTD group (n = 219) than the control group (n = 217). No adverse effects of DTD were observed in the 11 RCTs reviewed. All 11 studies used an appropriate method for randomization of subjects to evaluate the risk of bias (ROB), and 7 studies included allocation concealment as well as blinding of patients and practitioners. High-risk ROB was included in 6 RCTs. No significant publication bias was derived from the funnel plot. Our results indicate that the administration of DTD alone, and DTD in combination with Western medicine, exert greater efficacy for post-stroke complication therapy, than Western medicine administered alone. More rigorous and regulated studies are required to confirm the therapeutic efficacy of DTD for post-stroke neurological disorders. disorders.

Detecting the extent of control over selection bias relating to oral health and otorhinolaryngology: cross-sectional study

ABSTRACT BACKGROUND: The authors of randomized controlled trials will usually claim that they have met the randomization process criterion. However, sequence generation schemes differ and some schemes that are claimed to be randomized are not genuinely randomized. Even less well understood, and often more difficult to ascertain, is whether the allocation was really concealed. OBJECTIVE: To detect the extent of control over selection bias, in a comparison between two Cochrane groups: oral health and otorhinolaryngology; and to describe the methods used to control for this bias. DESIGN AND SETTING: Cross-sectional study conducted in a public university in São Paulo, Brazil. METHODS: The risk of selection bias in 1,714 records indexed in Medline database up to 2018 was assessed, independent of language and access. Two dimensions implicated in the allocation were considered: generation of the allocation sequence; and allocation concealment. RESULTS: We included 420 randomized controlled trials and all of them were evaluated to detect selection bias. In the sample studied, only 28 properly controlled the selection bias. Lack of control over selection bias was present in 80% of the studies evaluated in both groups. CONCLUSION: The two groups were similar regarding control over selection bias. They are also similar to the methods used. The dimension of allocation concealment appears to be a limiting factor with regard to production of randomized controlled trials with low risk of selection bias. The quality of reporting in studies on oral health and otorhinolaryngology is suboptimal and needs to be improved, in line with other fields of healthcare.

Introduction on 'assessing the risk of bias of individual studies' in systematic review of healthcare intervention programs revised by the Agency for Healthcare Research and Quality / 中华流行病学杂志

This paper summarizes the Risk of Bias of Individual Studies in Systematic Reviews of Health Care Interventions revised by the Agency for Healthcare Research and Quality (AHRQ) and introduces how to use Revman software make risk of bias graph or risk of bias summary.AHRQ tool can be used to evaluate following study designs:RCTs,cohort study,case-control study (including nested case-control),case series study and cross-sectional study.The tool evaluates the risk of bias of individual studies from selection bias,performance bias,attrition bias,detection bias and reporting bias.Each of the bias domains contains different items,and each item is available for the assessment of one or more study designs.It is worth noting that the appropriate items should be selected for evaluation different study designs instead of using all items to directly assess the risk of bias.AHRQ tool can be used to evaluate risk of bias individual studies when systematic reviews of health care interventions is including different study designs.Moreover,the tool items are relatively easy to understand and the assessment process is not complicated.AHRQ recommends the use of high,medium and low risk classification methods to assess the overall risk of bias of individual studies.However,AHRQ gives no recommendations on how to determine the overall bias grade.It is expected that future research will give corresponding recommendations.

Introduction on 'assessing the risk of bias of individual studies' in systematic review of healthcare intervention programs revised by the Agency for Healthcare Research and Quality / 中华流行病学杂志

This paper summarizes the Risk of Bias of Individual Studies in Systematic Reviews of Health Care Interventions revised by the Agency for Healthcare Research and Quality (AHRQ) and introduces how to use Revman software make risk of bias graph or risk of bias summary.AHRQ tool can be used to evaluate following study designs:RCTs,cohort study,case-control study (including nested case-control),case series study and cross-sectional study.The tool evaluates the risk of bias of individual studies from selection bias,performance bias,attrition bias,detection bias and reporting bias.Each of the bias domains contains different items,and each item is available for the assessment of one or more study designs.It is worth noting that the appropriate items should be selected for evaluation different study designs instead of using all items to directly assess the risk of bias.AHRQ tool can be used to evaluate risk of bias individual studies when systematic reviews of health care interventions is including different study designs.Moreover,the tool items are relatively easy to understand and the assessment process is not complicated.AHRQ recommends the use of high,medium and low risk classification methods to assess the overall risk of bias of individual studies.However,AHRQ gives no recommendations on how to determine the overall bias grade.It is expected that future research will give corresponding recommendations.

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.

Risk of bias assessment: (9) Application of the risk of bias assessment results / 中华流行病学杂志

In this last paper of the series about risk of bias assessment,we introduce the application of risk of bias assessment results.Risk of bias assessment is one of the key steps in the assessment of quality of evidence.The risk of bias assessment results could be the “diagnosis” of individual studies,which helps decision making related to the inclusion and exclusion of individual studies,as well as the data analysis in the systematic review process.This paper focuses on how to incorporate risk of bias assessment results in the GRADE assessment for quality of evidence,including the principles and the tips for the application.

Risk of bias assessment: (8) Risk of Bias in Systematic Review (ROBIS) / 中华流行病学杂志

This paper introduces the Risk of Bias in Systematic Review (ROBIS),including:1) the development of ROBIS,2) three phases of ROBIS tool judging the overall risk of bias that related to systematic reviews,and 3) illustration on the application of ROBIS in a published systematic review.ROBIS is the first rigorously developed tool which is specifically designed to assess the risk of bias in systematic reviews.ROBIS will help improve the process of risk assessmcnt on bias which appeared in overviews and guidelines.

Risk of bias assessment: (7) Assessing Bias in Studies of Prognostic Factors / 中华流行病学杂志

This paper introduces the tools related to Quality In Prognosis Studies (QUIPS) to assess the risk of bias in studies of prognostic factors and the relevant points of assessment and to illustrate the application of QUIPS in published prognostic research.The QUIPS tool identified 6 important areas to consider when evaluating validity and bias in studies of prognostic factors including participation,attrition,measurement on prognostic factors,outcomes,confounding factors,statistical analysis and reporting.It also provided a new method for evaluation on bias in the areas of prognostic research.

Risk on bias assessment: (6) A Revised Tool for the Quality Assessment on Diagnostic Accuracy Studies(QUADAS-2) / 中华流行病学杂志

This paper introduced the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2),including the development and comparison with the original QUADAS,and illustrated the application of QUADAS-2 in a published paper related to the study on diagnostic accuracy which was included in systematic review and Meta-analysis.QUADAS-2 presented considerable improvement over the original tool.Confused items that included in QUADAS had disappeared and the quality assessment of the original study replaced by the rating of risk on bias and applicability.This was implemented through the description on the four main domains with minimal overlapping and answering the signal questions in each domain.The risk of bias and applicability with'high','low'or'unclear'was in line with the risk of bias assessment of intervention studies in Cochrane,so to replace the total score of quality assessment in QUADAS.Meanwhile,QUADAS-2 was also applicable to assess the diagnostic accuracy studies in which follow-up without prognosis was involved in golden standard.It was useful to assess the overall methodological quality of the study despite more time consuming than the original QUADAS.However,QUADAS-2 needs to be modified to apply in comparative studies on diagnostic accuracy and we hope the users would follow the updates and give their feedbacks on line.

Series of risk of bias assessment (5): Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) / 中华流行病学杂志

This paper summaries the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I),a tool for evaluating risk of bias about Non-randomized Studies-of Interventions (NRSI),and introduces the application of ROBINS-I in a published NRSI.According to the characteristics of NRSI,evaluation field and signaling question were designed in ROBINS-I to provide essential information about risk of bias for NRSI included in systematic reviews.ROBINS-I is the tool in assessment of risk of bias in observational studies and quasi-randomised studies.Although the tool hasbeen used in practice to some extent,but it still needs further improvement.Attention should be paid to its update and progress.

Risk related to bias assessment: (4) Revised Cochrane Risk of Bias Tool for cluster-randomized control trials (RoB2.0) / 中华流行病学杂志

This paper introduced the Revised Cochrane Risk of Bias Tool RoB2.0 for cluster-randomized control trials (CRCT) and compared RoB2.0 of CRCT with individually randomized,parallel group trials,and illustrated the application of RoB2.0 for CRCT in a published CRCT.Special signal questions were designed for CRCT according to its specialty that different from individually randomized,parallel group trials in RoB2.0 and also providing information on risk of bias about CRCT in systematic reviews for the synthesis of evidence.

Risk of bias assessment: (9) Application of the risk of bias assessment results / 中华流行病学杂志

In this last paper of the series about risk of bias assessment,we introduce the application of risk of bias assessment results.Risk of bias assessment is one of the key steps in the assessment of quality of evidence.The risk of bias assessment results could be the “diagnosis” of individual studies,which helps decision making related to the inclusion and exclusion of individual studies,as well as the data analysis in the systematic review process.This paper focuses on how to incorporate risk of bias assessment results in the GRADE assessment for quality of evidence,including the principles and the tips for the application.

Risk of bias assessment: (8) Risk of Bias in Systematic Review (ROBIS) / 中华流行病学杂志

This paper introduces the Risk of Bias in Systematic Review (ROBIS),including:1) the development of ROBIS,2) three phases of ROBIS tool judging the overall risk of bias that related to systematic reviews,and 3) illustration on the application of ROBIS in a published systematic review.ROBIS is the first rigorously developed tool which is specifically designed to assess the risk of bias in systematic reviews.ROBIS will help improve the process of risk assessmcnt on bias which appeared in overviews and guidelines.

Risk of bias assessment: (7) Assessing Bias in Studies of Prognostic Factors / 中华流行病学杂志

This paper introduces the tools related to Quality In Prognosis Studies (QUIPS) to assess the risk of bias in studies of prognostic factors and the relevant points of assessment and to illustrate the application of QUIPS in published prognostic research.The QUIPS tool identified 6 important areas to consider when evaluating validity and bias in studies of prognostic factors including participation,attrition,measurement on prognostic factors,outcomes,confounding factors,statistical analysis and reporting.It also provided a new method for evaluation on bias in the areas of prognostic research.

Risk on bias assessment: (6) A Revised Tool for the Quality Assessment on Diagnostic Accuracy Studies(QUADAS-2) / 中华流行病学杂志

This paper introduced the Revised Tool for the Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2),including the development and comparison with the original QUADAS,and illustrated the application of QUADAS-2 in a published paper related to the study on diagnostic accuracy which was included in systematic review and Meta-analysis.QUADAS-2 presented considerable improvement over the original tool.Confused items that included in QUADAS had disappeared and the quality assessment of the original study replaced by the rating of risk on bias and applicability.This was implemented through the description on the four main domains with minimal overlapping and answering the signal questions in each domain.The risk of bias and applicability with'high','low'or'unclear'was in line with the risk of bias assessment of intervention studies in Cochrane,so to replace the total score of quality assessment in QUADAS.Meanwhile,QUADAS-2 was also applicable to assess the diagnostic accuracy studies in which follow-up without prognosis was involved in golden standard.It was useful to assess the overall methodological quality of the study despite more time consuming than the original QUADAS.However,QUADAS-2 needs to be modified to apply in comparative studies on diagnostic accuracy and we hope the users would follow the updates and give their feedbacks on line.

Series of risk of bias assessment (5): Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I) / 中华流行病学杂志

This paper summaries the Risk Of Bias In Non-randomized Studies-of Interventions (ROBINS-I),a tool for evaluating risk of bias about Non-randomized Studies-of Interventions (NRSI),and introduces the application of ROBINS-I in a published NRSI.According to the characteristics of NRSI,evaluation field and signaling question were designed in ROBINS-I to provide essential information about risk of bias for NRSI included in systematic reviews.ROBINS-I is the tool in assessment of risk of bias in observational studies and quasi-randomised studies.Although the tool hasbeen used in practice to some extent,but it still needs further improvement.Attention should be paid to its update and progress.

Risk related to bias assessment: (4) Revised Cochrane Risk of Bias Tool for cluster-randomized control trials (RoB2.0) / 中华流行病学杂志

This paper introduced the Revised Cochrane Risk of Bias Tool RoB2.0 for cluster-randomized control trials (CRCT) and compared RoB2.0 of CRCT with individually randomized,parallel group trials,and illustrated the application of RoB2.0 for CRCT in a published CRCT.Special signal questions were designed for CRCT according to its specialty that different from individually randomized,parallel group trials in RoB2.0 and also providing information on risk of bias about CRCT in systematic reviews for the synthesis of evidence.

Methodological quality and reporting quality evaluation of randomized controlled trials published in China Journal of Chinese Materia Medica / 中国中药杂志

To evaluate the methodological quality and reporting quality of randomized controlled trials(RCTs) published in China Journal of Chinese Materia Medica, we searched CNKI and China Journal of Chinese Materia webpage to collect RCTs since the establishment of the magazine. The Cochrane risk of bias assessment tool was used to evaluate the methodological quality of RCTs. The CONSORT 2010 list was adopted as reporting quality evaluating tool. Finally, 184 RCTs were included and evaluated methodologically, of which 97 RCTs were evaluated with reporting quality. For the methodological evaluating, 62 trials(33.70%) reported the random sequence generation; 9(4.89%) trials reported the allocation concealment; 25(13.59%) trials adopted the method of blinding; 30(16.30%) trials reported the number of patients withdrawing, dropping out and those lost to follow-up;2 trials （1.09%） reported trial registration and none of the trial reported the trial protocol; only 8(4.35%) trials reported the sample size estimation in details. For reporting quality appraising, 3 reporting items of 25 items were evaluated with high-quality,including: abstract, participants qualified criteria, and statistical methods; 4 reporting items with medium-quality, including purpose, intervention, random sequence method, and data collection of sites and locations; 9 items with low-quality reporting items including title, backgrounds, random sequence types, allocation concealment, blindness, recruitment of subjects, baseline data, harms, and funding;the rest of items were of extremely low quality(the compliance rate of reporting item<10%). On the whole, the methodological and reporting quality of RCTs published in the magazine are generally low. Further improvement in both methodological and reporting quality for RCTs of traditional Chinese medicine are warranted. It is recommended that the international standards and procedures for RCT design should be strictly followed to conduct high-quality trials. At the same time, in order to improve the reporting quality of randomized controlled trials, CONSORT standards should be adopted in the preparation of research reports and submissions.