Methods for Comparing the Results of Different Studies (original) (raw)
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Quality Assessment of Randomized Controlled Trials of Oral Implants
2001
The aim of this study was to assess the quality of randomized controlled trials (RCTs) concerned with the effectiveness of oral implants and to create a trial register. A multilayered search strategy was used to identify all RCTs published by the end of 1999 in any language. The Cochrane Oral Health Group specialist register, PubMed, and personal libraries were searched. Seventy-four RCTs were identified. Forty-three articles, not presenting the same patient material, were independently assessed by 3 researchers using a specially designed form. A statistician assessed all trials for the appropriateness of statistics. The quality of each study was assessed on 7 items, including 3 key domains. Randomization and concealment allocation procedures were not described in 30 articles (70%). Reasons for withdrawals were not given in 10 reports (23%). No attempt at blinding was reported in 31 studies (72%). The quality of RCTs of oral implants is generally poor and needs to be improved. (INT J ORAL MAXILLO-FAC IMPLANTS 2001;16:783-792)
SUMMARY The purpose of this study was to examine the reporting quality of randomised controlled trials (RCTs) published in prosthodontic and implantology journals. Thirty issues of nine journals in prosthodontics and implant dentistry were searched for RCTs, covering the years 2005–2012:The Journal of Prosthetic Dentistry, Journal of Oral Rehabilitation, The International Journal of Prosthodontics, The International Journal of Periodontics & Restorative Dentistry, Clinical Oral Implants Research, Clinical Implant Dentistry & Related Research, The International Journal of Oral & Maxillofacial Implants, Implant Dentistry and Journal of Dentistry. The reporting quality was assessed using a modified Consolidated Standards of Reporting Trials (CONSORT) statement checklist. Data were analysed using descriptive statistics followed by univariable andmultivariableexaminationof statistical associations (a=0.05). A total of 147 RCTs were identified with a mean CONSORT score of 69.4 (s.d.=9.7). Significant differences were found among journals with the Journal of Oral Rehabilitation achieving the highest score (80.6, s.d.=5.5) followed by Clinical Oral Implants Research (737, s.d.=83). Involvement of a statistician/methodologist was significantly associated with increased CONSORT scores. Overall, the reporting quality of RCTs in major prosthodontic and implantology journals requires improvement. This is of paramount importance considering that optimal reporting of RCTs is an important prerequisite for clinical decision-making. KEYWORDS:randomised clinical trials, prosthodontics, dental implants
An Overview of Characteristics of Registered Studies on Dental Implants
Journal of Evidence Based Dental Practice, 2014
Objective: Clinical trials serve as the empirical basis for clinical decision making. The objective of the current study is to provide an overview of clinical trials examining dental implant outcomes. Method: All registered studies on Dental Implants were selected for analysis. The clinicaltrials.gov http://clinicaltrials.gov/ website was used to query the characteristics of registered studies. The search term used was dental implants. Results: As of the study conduct date (01/01/2014), a total of 205 studies on dental implants were registered. These included 168 interventional and 37 observational studies. Results were available for only 14 studies. All observational studies and 98.8% of interventional studies included both male and female subjects. Close to 60% of studies had sample sizes between 1 and 50. NIH was listed as funding source in only 5 interventional studies and 3 observational studies. 80% of interventional studies were randomized. However, double masking was reported in only 15% of interventional studies with majority being open labeled. Conclusion: ClinicalTrials.gov registry was created with the intention of increasing the transparency of conducted or ongoing clinical studies and to minimize publication bias commonly seen with industry-sponsored studies. Results of the current study showed that a predominating number of registered studies are funded by industry and other sources, very few registered studies have made their results public, and the ClinicalTrials.gov registry
Clinical Implant Dentistry and Related Research, 2001
Background: It is difficult to determine the effectiveness or potential harm of dental therapies. Thus, any tools able to condense reliable scientific information would be of benefit.Purpose: To discuss methods for the assessment of the scientific literature and, in particular, of systematic reviews for evaluating the effectiveness of oral implant rehabilitation procedures.Materials and Methods: Various study designs and methods to identify scientific evidence are described, discussed, and ranked. Issues on how to critically appraise randomized controlled clinical trials (RCTs) and systematic reviews are presented.Results: Properly conducted RCTs and structured critical systematic reviews are the gold standard of clinical research for assessing whether a therapeutic intervention is effective. In the field of oral implantology, there is an urgent need to implement more RCTs and to summarize their results in systematic reviews.Conclusions: Searching of the truth requires training and critical skill. Dentists should be trained on how to integrate their clinical experience with evidence-based research and on how to discriminate between clinically useful scientific information and less useful research.
The reporting quality of Randomised Controlled Trials in Orthodontics
Journal of Evidence Based Dental Practice, 2014
Systematic reviews a b s t r a c t Objectives: Abstracts of systematic reviews are of critical importance, as consumers of research often do not access the full text. This study aimed to assess the reporting quality of systematic review (SR) abstracts in leading oral implantology journals.
Purpose: Confidence intervals (CIs) are integral to the interpretation of the precision and clinical relevance of research findings. The aim of this study was to ascertain the frequency of reporting of CIs in leading prosthodontic and dental implantology journals and to explore possible factors associated with improved reporting. Materials and Methods: Thirty issues of nine journals in prosthodontics and implant dentistry were accessed, covering the years 2005 to Dentistry. Articles were screened and the reporting of CIs and P values recorded. Other information including study design, region of authorship, involvement of methodologists, and ethical approval was also obtained. Univariable and multivariable logistic regression was used to identify characteristics associated with reporting of CIs. Results: Interrater agreement for the data extraction performed was excellent (kappa = 0.88; 95% CI: 0.87 to 0.89). CI reporting was limited, with mean reporting across journals of 14%. CI reporting was associated with journal type, study design, and involvement of a methodologist or statistician. Conclusions: Reporting of CI in implant dentistry and prosthodontic journals requires improvement. Improved reporting will aid appraisal of the clinical relevance of research findings by providing a range of values within which the effect size lies, thus giving the end user the opportunity to interpret the results in relation to clinical practice.
A Descriptive Analysis of Clinical Articles Published in the Last 50 Years in the Dental Literature
The Journal of Contemporary Dental Practice
Aims: This article describes the methodologies used in the dental literature and described how these approaches have changed over time. Materials and methods: Thirty-three ISI peer-reviewed journals were included in the analyses. Data were extracted independently by 11 investigators and in duplicate. Any differences in the results were resolved via discussion or by a third reviewer when necessary. Data were collected regarding the methodology used in the article, and dental specialty related to different study designs. In the case in which more than one study design or specialty was reported, reviewers were trained to identify the main methodology/specialty. Results: The majority (36.96%) used a case report (CR) as the primary methodology, followed by a clinical trial (CT) (18.21%) or randomized CT (15.11%). The least used methodologies included a cohort (COH) study (6.07%) or a systematic review (SA)/meta-analysis (MA) (6.73%). Periodontology published the highest number of case controls (CCs) (46.8%), randomized CTs (RCTs) (29.9%), cross-sectional (CS) studies (26.0%), SRs/MAs (19.8%), and CTs (17.1%). Oral and maxillofacial surgery published the highest number of CRs/case series (54.5%) and COH studies (30.5%), whereas operative dentistry published the lowest number of CRs/case series (0.7%), CCs (2.9%), and SRs/MAs (2.3%). CRs/case series retain the highest number of publications across all time points in the dental literature overall. Conclusion: Our results indicate an improvement in the types of research and the pyramid of evidence, which will help in applying evidencebased dentistry (EBD) in clinical decision-making. Clinical significance: Types of studies used in the dental field are not yet investigated. Thus, little is known about the common study design types in dental literature. This can affect the decision made regarding technique, risk factors, prevention, or treatment.
Risk of bias in research in oral and maxillofacial surgery
British Journal of Oral and Maxillofacial Surgery, 2013
The risk of bias is important in the interpretation of the results of research. The aim of this review was to evaluate the risk of bias in randomised controlled trials (RCTs) in oral and maxillofacial surgery (OMFS) over a 10-year period. We searched databases of publications for RCTs published between January 2000 and January 2010. Papers were assessed with 2 up-to-date logical quality lists, the Delphi list and the Jadad scale. Those papers with a low risk of bias were given a Jadad score ≥4 (range 0-5) and a Delphi score ≥6 (range 0-9).
Objectives: To assess the hypothesis that there is excessive reporting of statistically significant studies published in prosthodontic and implantology journals, which could indicate selective publication. Methods: The last 30 issues of 9 journals in prosthodontics and implant dentistry were hand-searched for articles with statistical analyses. The percentages of significant and non-significant results were tabulated by parameter of interest. Univariable/multivariable logistic regression analyses were applied to identify possible predictors of reporting statistically significance findings. The results of this study were compared with similar studies in dentistry with random-effects meta-analyses. Results: From the 2323 included studies 71% of them reported statistically significant results, with the significant results ranging from 47% to 86%. Multivariable modeling identified that geographical area and involvement of statistician were predictors of statistically significant results. Compared to interventional studies, the odds that in vitro and observational studies would report statistically significant results was increased by 1.20 times (OR: 2.20, 95% CI: 1.66–2.92) and 0.35 times (OR: 1.35, 95% CI: 1.05–1.73), respectively. The probability of statistically significant results from randomized controlled trials was significantly lower compared to various study designs (difference: 30%, 95% CI: 11–49%). Likewise the probability of statistically significant results in prosthodontics and implant dentistry was lower compared to other dental specialties, but this result did not reach statistical significant (P > 0.05). Conclusions: The majority of studies identified in the fields of prosthodontics and implant dentistry presented statistically significant results. The same trend existed in publications of other specialties in dentistry.