Assessing the risk of bias in randomized controlled trials in the field of dentistry indexed in the Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) database / Avaliação do risco de viés de ensaios controlados randomizados de odontologia indexados na base de dados Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde)

CONTEXT AND OBJECTIVE: Well-conducted randomized controlled trials (RCTs) represent the highest level of evidence when the research question relates to the effect of therapeutic or preventive interventions. However, the degree of control over bias between RCTs presents great variability between studies. For this reason, with the increasing interest in and production of systematic reviews and meta-analyses, it has been necessary to develop methodology supported by empirical evidence, so as to encourage and enhance the production of valid RCTs with low risk of bias. The aim here was to conduct a methodological analysis within the field of dentistry, regarding the risk of bias in open-access RCTs available in the Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) database. DESIGN AND SETTING: This was a methodology study conducted at Universidade Federal de São Paulo (Unifesp) that assessed the risk of bias in RCTs, using the following dimensions: allocation sequence generation, allocation concealment, blinding, and data on incomplete outcomes. RESULTS: Out of the 4,503 articles classified, only 10 studies (0.22 percent) were considered to be true RCTs and, of these, only a single study was classified as presenting low risk of bias. The items that the authors of these RCTs most frequently controlled for were blinding and data on incomplete outcomes. CONCLUSION: The effective presence of bias seriously weakened the reliability of the results from the dental studies evaluated, such that they would be of little use for clinicians and administrators as support for decision-making processes.

CONTEXTO E OBJETIVO: Ensaios controlados randomizados (ECRs) bem conduzidos representam o mais alto nível de evidência quando a pergunta de pesquisa é sobre o efeito de intervenções terapêuticas ou preventivas. No entanto, o grau de controle de viés entre os ECRs apresenta grande variabilidade entre estudos. Por esta razão, com o aumento do interesse e produção das revisões sistemáticas e metanálises, foi necessário desenvolver metodologia suportada por evidência empírica, para incentivar e valorizar a produção de ECRs válidos e com baixo risco de viés. O objetivo deste trabalho foi realizar uma análise metodológica da área de odontologia quanto ao risco de viés de ECRs de acesso aberto, disponibilizados no banco de dados do Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde). TIPO DE ESTUDO E LOCAL: Trata-se de um estudo sobre metodologia conduzido na Universidade Federal de São Paulo (Unifesp) que avaliou o risco de viés dos ECRs, utilizando as seguintes dimensões: geração da sequência de alocação, sigilo da alocação, cegamento e dados sobre desfechos incompletos. RESULTADOS: Dos 4.503 artigos classificados somente 10 (0,22 por cento) estudos foram considerados verdadeiros ECR e, destes, somente um estudo foi classificado como sendo de baixo risco de viés. Os itens mais frequentemente controlados pelos autores dos ECR foram cegamento e dados sobre desfechos incompletos. CONCLUSÃO: A presença efetiva de viés enfraqueceu seriamente a confiança nos resultados dos estudos de odontologia avaliados, sendo pouco úteis para clínicos e gestores como suporte a processos de decisão.

Validity of Qualis database as a predictor of evidence hierarchy and risk of bias in randomized controlled trials: a case study in dentistry

OBJECTIVE: To evaluate the validity of the Qualis database in identifying the levels of scientific evidence and the quality of randomized controlled trials indexed in the Lilacs database. METHODS: We selected 40 open-access journals and performed a page-by-page hand search, to identify published articles according to the type of study during a period of six years. Classification of studies was performed by independent reviewers assessed for their reliability. Randomized controlled trials were identified for separate evaluation of risk of bias using four dimensions: generation of allocation sequence, allocation concealment, blinding, and incomplete outcome data. The Qualis classification was considered to be the outcome variable. The statistical tests used included Kappa, Spearman's correlation, Kendall-tau and ordinal regressions. RESULTS: Studies with low levels of scientific evidence received similar Qualis classifications when compared to studies with high levels of evidence. In addition, randomized controlled trials with a high risk of bias for the generation of allocation sequences and allocation concealment were more likely to be published in journals with higher Qualis levels. DISCUSSION: The hierarchy level of the scientific evidence as classified by type of research design, as well as by the validity of studies according to the bias control level, was not correlated or associated with Qualis stratification. CONCLUSION: Qualis classifications for journals are not an approximate or indirect predictor of the validity of randomized controlled trials published in these journals and are therefore not a legitimate or appropriate indicator of the validity of randomized controlled trials.