scholarly journals Quality assessment of studies included in Cochrane oral health systematic reviews

Author(s):  
Ahmad Sofi-Mahmudi ◽  
Pouria Iranparvar ◽  
Maryam Shakiba ◽  
Erfan Shamsoddin ◽  
Hossein Mohammad-Rahimi ◽  
...  

AbstractObjectivesThe Risk of Bias (RoB) and other characteristics of randomized clinical trials included in Cochrane oral health systematic reviews were assessed.Study Design and SettingsAll the trials included in Cochrane oral health systematic reviews were examined. The RoB was evaluated for all the included clinical trials according to the Cochrane review standards. The Overall Risk of Bias (ORoB) was defined in this study based on the criteria for determining the overall bias in Cochrane’s RoB tool-v2. Descriptive analyses were carried out to determine the frequency of each intended variable.ResultsA total of 2565 studies were included in our analysis. The majority of the studies (n=1600) had sample sizes of 50 or higher. As for blinding, 907 studies were labelled as double-blind. Performance bias showed the highest rate of high risk (31.4%). Almost half of the studies had a high ORoB compared to 11.1% with low ORoB. The studies that used placebos had higher low ORoB (14.8% vs. 10.7%). The double-blind studies had the highest low ORoB (23.6%). The studies with a cross-over design had the highest low ORoB (28.8%).ConclusionOverall, the RoB for the studies on dentistry and oral health in Cochrane reviews was deemed high.

2021 ◽  
Author(s):  
Ahmad Sofi-Mahmudi ◽  
Pouria Iranparvar ◽  
Maryam Shakiba ◽  
Erfan Shamsoddin ◽  
Hossein Mohammad-Rahimi ◽  
...  

Abstract Background: Risk of Bias (RoB) and other characteristics of randomised clinical trials included in Cochrane oral health systematic reviews were assessed.Methods: All the trials included in Cochrane oral health systematic reviews were identified and examined. The RoB was evaluated for all the included clinical trials according to the Cochrane review standards. The Overall Risk of Bias (ORoB) was defined in this study based on the criteria in Cochrane’s RoB tool-v2. Descriptive analyses were carried out to determine the frequency of each intended variable.Results: In a total of 2565 included studies, the majority (n=1600) had 50 or higher sample sizes. As for blinding, 907 studies were labelled as double-blind. Performance bias showed the highest rate of high risk (31.4%). Almost half of the studies had a high ORoB compared to 11.1% with low ORoB. The studies that used placebos had higher low ORoB (14.8% vs 10.7%). The double-blind studies had the highest low ORoB (23.6%). The studies with a cross-over design had the highest low ORoB (28.8%).Conclusion: The RoB of oral health studies in Cochrane reviews was deemed high. Special efforts may be required to improve conducting and reporting of trials in this area.


Author(s):  
Ahmad Sofi-Mahmudi ◽  
Pouria Iranparvar ◽  
Maryam Shakiba ◽  
Erfan Shamsoddin ◽  
Hossein Mohammad-Rahimi ◽  
...  

Objectives: To assess the Risk of Bias (RoB) and other characteristics of published randomised clinical trials within Cochrane oral health systematic reviews. Materials and methods: All the published clinical trials within Cochrane oral health systematic reviews until June 1, 2020 were identified and examined. RoB was assessed for all the included clinical trials according to the Cochrane review standards. The Overall Risk of Bias (ORoB) was defined in this study using Cochrane’s RoB tool-v2. Descriptive analyses were carried out to determine the frequency of each variable in the study sample. Results: Out of a total of 2565 included studies, the majority (n = 1600) had sample sizes of 50 or higher. Regarding blinding, 907 studies were labelled as double-blind. Among the various domains of bias, the performance bias showed the highest rate of high risk (31.4%). Almost half of the studies had a high ORoB, compared to 11.1% with a low ORoB. The studies that used placebos had a higher percentage of low ORoB (14.8% vs. 10.7%). Additionally, the double- and triple-blind studies had higher percentages of low ORoB (23.6% and 23.3%, respectively), while the studies with a crossover design had the highest percentage of low ORoB (28.8%). Conclusion: The RoB of oral health studies published as Cochrane reviews was deemed high.


2020 ◽  
Vol 49 (5) ◽  
pp. 495-502
Author(s):  
Stephanie Wintzer ◽  
Josef Georg Heckmann ◽  
Hagen B. Huttner ◽  
Stefan Schwab

<b><i>Background:</i></b> Spontaneous intracerebral hemorrhage (ICH) is a frequent cerebrovascular disorder and still associated with high mortality and poor clinical outcomes. The purpose of this review was to update a 15-year-old former meta-analysis on randomized clinical trials (RCTs) addressing the question of whether ICH patients treated with dexamethasone have better outcomes than controls. <b><i>Methods:</i></b> The electronic databases PubMed, SCOPUS, and Cochrane as well as web platforms on current clinical trials were searched for the years 1970–2020 without constriction on language. Data were extracted and outcomes were pooled for conventional and cumulative meta-analysis using a commercial software program (www.Meta-Analysis.com). <b><i>Results:</i></b> Finally, 7 RCTs were identified and analyzed including 248 participants in the dexamethasone groups and 242 in the control groups. Five studies showed a high risk of bias. The overall relative risk (RR) for death was 1.32 (95% confidence interval [CI] 0.99–1.76; <i>p</i> = 0.06) and did not differ significantly between the 2 groups. After exclusion of studies with high risk of bias, the RR for death was 1.37 (95% CI 0.54–3.42; <i>p</i> = 0.51). The RR for poor outcome did not differ significantly between the 2 groups analyzed for all included studies (RR = 0.69; 95% CI 0.47–1; <i>p</i> = 0.05) and after exclusion of studies with high risk of bias (RR = 0.7; 95% CI 0.45–1.08; <i>p</i> = 0.11). The RR for complications did not differ significantly including all studies (RR = 1.29; 95% CI 0.77–2.17; <i>p</i> = 0.34) and after exclusion of studies with high risk of bias (RR = 1.27; 95% CI 0.18–8.89; <i>p</i> = 0.81). The cumulative statistics delivered no other results; however, it pointed out fewer complications over time in the dexamethasone group. <b><i>Conclusion:</i></b> Clear evidence of a beneficial or negative effect of dexamethasone is still lacking. Modern RCTs or observational studies with propensity design are necessary to evaluate the efficacy and safety of treatment with dexamethasone in patients with ICH.


2018 ◽  
Vol 43 (3) ◽  
pp. E129-E151 ◽  
Author(s):  
A Reis ◽  
JL de Geus ◽  
L Wambier ◽  
M Schroeder ◽  
AD Loguercio

SUMMARY The literature was reviewed to evaluate the compliance of randomized clinical trials (RCTs) with the CONsolidated Standards of Reporting Trials (CONSORT ) and the risk of bias of these studies through the Cochrane Collaboration risk of bias tool (CCRT). RCTs were searched at Cochrane Library, PubMed, and other electronic databases to find studies about adhesive systems for cervical lesions. The compliance of the articles with CONSORT was evaluated using the following scale: 0 = no description, 1 = poor description, and 2 = adequate description. Descriptive analyses about the number of studies by journal, follow-up period, country, and quality assessments were performed with CCRT for assessing risk of bias in RCTs. One hundred thirty-eight RCTs were left for assessment. More than 30% of the studies received scores of 0 or 1. Flow chart, effect size, allocation concealment, and sample size were more critical items, with 80% receiving a score of 0. The overall CONSORT score for the included studies was 15.0 ± 4.8 points, which represents 46.9% of the maximum CONSORT score. A significant difference among countries was observed (p&lt;0.001), as well as range of year (p&lt;0.001). Only 4.3% of the studies were judged as at low risk; 36.2% were classified as having unclear risk and 59.4% as having high risk of bias. The adherence of RCTs evaluating adhesive systems to the CONSORT is low with unclear/high risk of bias.


2021 ◽  
Vol 39 ◽  
Author(s):  
Paola Janeiro Valenciano ◽  
Fabíola Unbehaun Cibinello ◽  
Jessica Caroliny de Jesus Neves ◽  
Dirce Shizuko Fujisawa

ABSTRACT Objective: To determine the effect of postural education on the learning and postural habits of elementary school children without physical intervention. Methods: We searched PubMed, Lilacs, SciELO, Cochrane, and Science Direct data bases and reference lists of studies in February 2020. The eligibility criteria were randomized clinical trials related to the effect of postural education in children aged between 6 and 12 years old. Two authors independently assessed trials for inclusion and risk of bias: randomization process, deviations from intended interventions, missing outcome data, measurement of the outcome, and selection of the reported result. Data were extracted in standardized tables including information on author, publication year, country, sample size, age, sex, intervention characteristics, outcome measurements and results. Results: We found seven clinical trials (involving 2,568 children) for the review. The studies were conducted between 2000 and 2018: four in Belgium, two in Spain, and one in Germany. All seven included trials underwent evaluation: only one had a clear process of randomization and allocation concealment. All included studies were judged as having high risk of bias in at least one domain or have concerns for multiple domains. Conclusions: The positive effects of acquired knowledge and postural habits found in the studies cannot be used to reliably support postural education in elementary school children due to a high risk of bias in the evaluated studies.


2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Ognjen Barcot ◽  
Matija Boric ◽  
Svjetlana Dosenovic ◽  
Livia Puljak

Abstract Background Initially, the Cochrane risk of bias (RoB) tool had a domain for “blinding of participants, personnel and outcome assessors”. In the 2011 tool, the assessment of blinding was split into two domains: blinding of participants and personnel (performance bias) and blinding of outcome assessors (detection bias). The aims of this study were twofold; first, to analyze the frequency of usage of the joint blinding domain (a single domain for performance and detection bias), and second, to assess the proportion of adequate assessments made in the joint versus single RoB domains for blinding by comparing whether authors’ RoB judgments were supported by explanatory comments in line with the Cochrane Handbook recommendations. Methods We extracted information about the assessment of blinding from RoB tables (judgment, comment, and whether it was specified which outcome type; e.g., objective, subjective) of 729 Cochrane reviews published in 2015-2016. In the Cochrane RoB tool, judgment (low, unclear or high risk) needs to be accompanied by a transparent comment, in which authors provide a summary justifying RoB judgment, to ensure transparency in how these judgments were reached. We reassessed RoB based on the supporting comments reported in Cochrane RoB tables, in line with instructions from the Cochrane Handbook. Then, we compared our new assessments to judgments made by Cochrane authors. We compared the frequency of adequate judgments in reviews with two separate domains for blinding versus those with a joint domain for blinding. Results The total number of assessments for performance bias was 6918, with 8656 for detection bias and 3169 for the joint domain. The frequency of adequate assessments was 74% for performance bias, 78% for detection bias, and 59% for the joint domain. The lowest frequency of adequate assessments was found when Cochrane authors judged low risk – 47% in performance bias, 62% in detection bias, and 31% in the joint domain. The joint domain and detection bias domain had a similar proportion of specified outcome types (17% and 18%, respectively). Conclusions Splitting joint RoB assessment about blinding into two domains was justified because the frequency of adequate judgments was higher in separate domains. Specification of outcome types in RoB domains should be further scrutinized.


2019 ◽  
Vol 25 (5) ◽  
pp. 573-585 ◽  
Author(s):  
Valentina Lucia La Rosa ◽  
Thaís Duarte de Campos da Silva ◽  
Arielle Rosa de Oliveira ◽  
Taís Marques Cerentini ◽  
Patricia Viana da Rosa ◽  
...  

The aim of this study was to systematically review randomized clinical trials comparing the treatment of individuals with overactive bladder syndrome through the use of behavioral therapy versus drug therapy. A systematic electronic search of MEDLINE via PubMed, Embase, and Cochrane Library was performed, including studies indexed until August 2019. Five randomized clinical trials were included. The studies presented a high risk of bias. There was no significant difference between the evaluated treatments. Thus, behavioral therapy and drug therapy also promote the improvement of the symptoms of overactive bladder syndrome, and the behavioral therapy does not have significant adverse effects reported. Due to the high risk of bias in included studies, data should be interpreted with caution. Future studies with more comprehensive protocols may change the effect estimates of behavioral therapy on overactive bladder syndrome.


BMJ Open ◽  
2014 ◽  
Vol 4 (10) ◽  
pp. e005491 ◽  
Author(s):  
Julie B Hansen ◽  
Carsten B Juhl ◽  
Isabelle Boutron ◽  
Peter Tugwell ◽  
Elizabeth A T Ghogomu ◽  
...  

IntroductionThe validity of systematic reviews and meta-analysis depends on methodological quality and unbiased dissemination of trials. Our objective is to evaluate the association of estimates of treatment effects with different bias-related study characteristics in meta-analyses of interventions used for treating pain in osteoarthritis (OA). From the findings, we hope to consolidate guidance on interpreting OA trials in systematic reviews based on empirical evidence from Cochrane reviews.Methods and analysisOnly systematic reviews that compare experimental interventions with sham, placebo or no intervention control will be considered eligible. Bias will be assessed with the risk of bias tool, used according to the Cochrane Collaboration’s recommendations. Furthermore, center status, trial size and funding will be assessed. The primary outcome (pain) will be abstracted from the first appearing forest plot for overall pain in the Cochrane review. Treatment effect sizes will be expressed as standardised mean differences (SMDs), where the difference in mean values available from the forest plots is divided by the pooled SD. To empirically assess the risk of bias in treatment benefits, we will perform stratified analyses of the trials from the included meta-analyses and assess the interaction between trial characteristics and treatment effect. A relevant study-level covariate is defined as one that decreases the between-study variance (τ2, estimated as Tau-squared) as a consequence of inclusion in the mixed effects statistical model.Ethics and disseminationMeta-analyses and randomised controlled trials provide the most reliable basis for treatment of patients with OA, but the actual impact of bias is unclear. This study will systematically examine the methodological quality in OA Cochrane reviews and explore the effect estimates behind possible bias. Since our study does not collect primary data, no formal ethical assessment and informed consent are required.Trial registration numberPROSPERO (CRD42013006924).


2016 ◽  
Vol 19 (3) ◽  
pp. 14
Author(s):  
José Augusto Sedrez-Porto ◽  
Mateus B F Dos Santos ◽  
Tatiana Pereira-Cenci

<p>A literature review was performed including studies that evaluated the use of cleaning protocols for removable dentures through questionnaires, clinical trials, randomized clinical trials, and systematic reviews. Twenty studies were included and the results showed that bad preservation of the prostheses is mainly due to low knowledge about cleaning habits and methods. Also, a wide variety of effective cleaning methods were presented. However, there is no standard protocol for all patients and it should be customized for each patient. It is important to highlight that dentists should give adequate instructions concerning maintenance and hygiene of the prosthesis.</p><p> </p><p><strong>Keywords</strong></p><p>Dental prosthesis; Oral hygiene; Oral health.</p>


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