60 research outputs found

    Coherence of evidence from systematic reviews as a basis for evidence strength - a case study in support of an epistemological proposition

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    <p>Abstract</p> <p>Background</p> <p>This article aims to offer, on the basis of Coherence theory, the epistemological proposition that mutually supportive evidence from multiple systematic reviews may successfully refute radical, philosophical scepticism.</p> <p>Methods</p> <p>A case study including seven systematic reviews is presented with the objective of refuting radical philosophical scepticism towards the belief that glass-ionomer cements (GIC) are beneficial in tooth caries therapy. The case study illustrates how principles of logical and empirical coherence may be applied as evidence in support of specific beliefs in healthcare.</p> <p>Results</p> <p>The results show that radical scepticism may epistemologically be refuted on the basis of logical and empirical coherence. For success, several systematic reviews covering interconnected beliefs are needed. In praxis, these systematic reviews would also need to be of high quality and its conclusions based on reviewed high quality trials.</p> <p>Conclusions</p> <p>A refutation of radical philosophical scepticism to clinical evidence may be achieved, if and only if such evidence is based on the logical and empirical coherence of multiple systematic review results. Practical application also requires focus on the quality of the systematic reviews and reviewed trials.</p

    The composite quality score for the appraisal of prospective controlled clinical therapy trials in systematic reviews and its limits

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    Systematic reviews of prospective controlled clinical therapy trials are one of the most important sources of information in modern medicine. Besides the systematic search for and statistical pooling of current clinical trial data for a particular type of therapy, systematic reviews also have the task of appraising the quality of trial results. The quality of trial results may be diminished by low internal trial validity, due to systematic error (bias). A high risk of bias may likely cause the reported trial results to be diverted from the actual true therapeutic effect and thus render it unsuitable for clinical guidance. According to the Cochrane Collaboration, the risk of bias in clinical therapy trials should be assessed using its Risk of Bias tool, Version 2 (RoB 2). However, the tool has been established to have poor inter-rater reliability, with a limited empirical evidence base and described as complex and demanding. Against this background, the composite quality score (CQS) has been developed as a possible alternative trial appraisal tool, characterised by high epistemic rigour, empirical evidence base, inter-rater reliability and ease of use. This article presents the current evidence of the CQS and its limitations

    Caries-preventive effect of glass ionomer and resin-based fissure sealants on permanent teeth: An update of systematic review evidence

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    Abstract Background This article constitutes a partial update of the original systematic review evidence by Yengopal et al. from 15 January 2008 (published in the Journal of Oral Science in 2009) with primary focus on research quality in regard to bias risk in trials. Its aim is to update the existing systematic review evidence from the English literature as to whether caries occurrence on pits and fissures of teeth sealed with either GIC or resin is the same. Methods In addition to the 12 trials included during the original systematic review, 5 new trials were identified during the database search (up to 26 August 2010) and 2 further trials were included from a hand search and reference check. Of these, 3 trials were excluded and 16 were accepted for data extraction and quality assessment. The quality of accepted trials was assessed, using updated quality criteria, and the risk of bias was investigated in more depth than previously reported. In addition, the focus of quantitative synthesis was shifted to single datasets that were extracted from the accepted trials. Results Twenty-six dichotomous and 4 continuous datasets were extracted. Meta-analysis and cumulative meta-analysis were used in combining clinically homogenous datasets. The overall outcome of the computed datasets suggest no difference between the caries-preventive effects of GIC- and resin-based fissure sealants. Conclusions This overall outcome is in agreement with the conclusions of the original systematic review. Although the findings of the trials identified in this update may be considered to be less affected by attrition- and publication bias, their risk of selection- and detection-/performance bias is high. Thus, verification of the currently available results requires further high quality randomised control trials.</p

    The modified Ottawa method to establish the update need of a systematic review: glass-ionomer versus resin sealants for caries prevention

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    OBJECTIVE: To demonstrate the application of the modified Ottawa method by establishing the update need of a systematic review with focus on the caries preventive effect of GIC versus resin pit and fissure sealants; to answer the question as to whether the existing conclusions of this systematic review are still current; to establish whether a new update of this systematic review was needed. METHODS: Application of the Modified Ottawa method. Application date: April/May 2012. RESULTS: Four signals aligned with the criteria of the modified Ottawa method were identified. The content of these signals suggest that higher precision of the current systematic review results might be achieved if an update of the current review were conducted at this point in time. However, these signals further indicate that such systematic review update, despite its higher precision, would only confirm the existing review conclusion that no statistically significant difference exists in the caries-preventive effect of GIC and resin-based fissure sealants. CONCLUSION: In conclusion, this study demonstrated the modified Ottawa method as an effective tool in establishing the update need of the systematic review. In addition, it was established that the conclusions of the systematic review in relation to the caries preventive effect of GIC versus resin based fissure sealants are still current, and that no update of this systematic review was warranted at date of application

    Tratamento Restaurador Atraumático (ART): fatores que afetam o sucesso

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    O sucesso de restaurações dentais resultante dos princípios do Tratamento Restaurador Atraumático (ART) é dependente de vários fatores clínicos. A falhas mais comuns decorrentes desses fatores estão relacionadas com o desgaste do material (>;0,5 mm); perda parcial do material; perda completa do material e cárie associada à margem da restauração. A principal razão para as falhas clínicas do ART está relacionada com a habilidade e performance do operador. A prevenção e controle das falhas do ART incluem ênfase na correta indicação e no reparo de restaurações falhas. Uma nova classificação de cáries pode servir de guia para a indicação clínica. A classificação combina localização e extensão da lesão, a qual é expressa em um sistema de código duplo. Adicionalmente, o treinamento e domínio durante a aplicação do ART são fatores importantes para o sucesso clínico.The success of tooth restorations rendered according to principles of the Atraumatic Restorative Treatment (ART) approach is dependant on various clinical factors. The most common failures, due to these factors, are partial material loss; complete material loss; caries related to restoration margin and material wear >; 0.5mm. The main reason for clinical ART failures are related to operator skills and performance. The prevention and management of ART failures includes emphasis on correct clinical indication and the repair of failed restorations. A new caries classification may provide guidance for clinical indication. The classification combines site and size of a lesion, which is reflected in a dual coding system. In addition, ART training and diligence during ART application are important for clinical success

    Risk of selection bias assessment in the NINDS rt‑PA stroke study

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    The NINDS rt-PA Stroke Study is frequently cited in support of alteplase for acute ischemic stroke within 3 h of symptom onset. Multiple post-hoc reanalyses of this trial have been published to adjust for a baseline imbalance in stroke severity. We performed a risk of selection bias assessment and reanalyzed trial data to determine if the etiology of this baseline imbalance was more likely due to random chance or randomization errors. A risk of selection bias assessment was conducted using signaling questions from the Cochrane Risk of Bias 2 (ROB 2) tool. Four sensitivity analyses were conducted on the trial data based on the randomization process: assessment of imbalances in allocation in unique strata; adherence to a pre-specified restriction on randomization between time strata at each randomization center; assessment of differences in baseline computed tomography (CT) results in unique strata; and comparison of baseline characteristics between allocation groups within each time strata. A multivariable logistic regression model was used to compare reported treatment effects with revised treatment effects after adjustment of baseline imbalances identified in the sensitivity analyses

    Inter-rater reliability of the extended Composite Quality Score (CQS-2)

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    AimTo establish the inter-rater reliability of the Composite Quality Score (CQS-2) and to test the null hypothesis that it did not differ significantly from that of the first CQS version (CQS-1).Materials and methodsFour independent raters were selected to rate 45 clinical trial reports using CQS-1 and CQS-2. The raters remained unaware of each other’s participation in this study until all rating had been completed. Each rater received only one rating template at a time in a random sequence for CQS-1 and CQS-2 rating. Raters completed each template and sent these back to the principal investigator. Each rater received their next template 2 weeks after submission of the completed previous template. The inter-rater reliabilities for the overall appraisal score of the CQS-1 and the CQS-2 were established by using the Brennan-Prediger coefficient (BPC). The coefficients of both CQS versions were compared by using the two-sample z-test. During secondary analysis, the BPCs for every criterion and each corroboration level for both CQS versions were established.ResultsThe BPC for the CQS-1 was 0.85 (95% CI: 0.64–1.00) and for the CQS-2 it was 1.00 (95% CI: 0.94–1.00), suggesting a very high inter-rater reliability for both. The difference between the two CQS versions was statistically not significant (p = 0.17). The null hypothesis was accepted.ConclusionThe CQS-2 is still under development, This study shows that it is associated with a very high inter-rater reliability, which did not statistically significantly differ from that of the CQS-1. The promising results of this study warrant further investigation in the applicability of the CQS-2 as an appraisal tool for prospective controlled clinical therapy trials

    Accuracy of the Berger-Exner test for detecting third-order selection bias in randomised controlled trials: a simulation-based investigation

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    BACKGROUND: Randomised controlled trials (RCT) are highly influential upon medical decisions. Thus RCTs must not distort the truth. One threat to internal trial validity is the correct prediction of future allocations (selection bias). The Berger-Exner test detects such bias but has not been widely utilized in practice. One reason for this non-utilisation may be a lack of information regarding its test accuracy. The objective of this study is to assess the accuracy of the Berger-Exner test on the basis of relevant simulations for RCTs with dichotomous outcomes. METHODS: Simulated RCTs with various parameter settings were generated, using R software, and subjected to bias-free and selection bias scenarios. The effect size inflation due to bias was quantified. The test was applied in both scenarios and the pooled sensitivity and specificity, with 95% confidence intervals for alpha levels of 1%, 5%, and 20%, were computed. Summary ROC curves were generated and the relationships of parameters with test accuracy were explored. RESULTS: An effect size inflation of 71% - 99% was established. Test sensitivity was 1.00 (95% CI: 0.99 – 1.00) for alpha level 1%, 5%, and 20%; test specificity was 0.94 (95% CI: 0.93 – 0.96); 0.82 (95% CI: 0.80 – 0.84), and 0.56 (95% CI: 0.54 – 0.58) for alpha 1%, 5%, and 20%, respectively. Test accuracy was best with the maximal procedure used with a maximum tolerated imbalance (MTI) = 2 as the randomisation method at alpha 1%. CONCLUSIONS: The results of this simulation study suggest that the Berger-Exner test is generally accurate for identifying third-order selection bias. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/1471-2288-14-114) contains supplementary material, which is available to authorized users

    Extension of the composite quality score (cqs) as an appraisal tool for prospective, controlled clinical therapy trials–A systematic review of meta-epidemiological evidence

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    To conduct a survey of current meta-epidemiological studies to identify additional trial design characteristics that may be associated with significant over- or underestimation of the treatment effect and to use such identified characteristics as a basis for the formulation of new CQS appraisal criteria. We retrieved eligible studies from two systematic reviews on this topic (latest search May 2015) and searched the databases PubMed and Embase for further studies from June 2015 –March 2022. All data were extracted by one author and verified by another. Sufficiently homogeneous estimates from single studies were pooled using random-effects meta-analysis. Trial design characteristics associated with statistically significant estimates from single datasets (which could not be pooled) and meta-analyses were used as a basis to formulate new or amend existing CQS criteria
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