https://www.commed.vcu.edu/Chronic_Disease/2012/cochranrvwrschbias.pdf

The Cochrane Collaboration's tool for assessing risk of bias in randomised trials

Clinical Trials: A Practical Approach

Placebo

Policy Points:

Currently, there is massive production of unnecessary, misleading, and conflicted systematic reviews and meta-analyses. Instead of promoting evidence-based medicine and health care, these instruments often serve mostly as easily produced publishable units or marketing tools.
Suboptimal systematic reviews and meta-analyses can be harmful given the major prestige and influence these types of studies have acquired.
The publication of systematic reviews and meta-analyses should be realigned to remove biases and vested interests and to integrate them better with the primary production of evidence.



Context
Currently, most systematic reviews and meta-analyses are done retrospectively with fragmented published information. This article aims to explore the growth of published systematic reviews and meta-analyses and to estimate how often they are redundant, misleading, or serving conflicted interests.

Methods
Data included information from PubMed surveys and from empirical evaluations of meta-analyses.

Findings
Publication of systematic reviews and meta-analyses has increased rapidly. In the period January 1, 1986, to December 4, 2015, PubMed tags 266,782 items as “systematic reviews” and 58,611 as “meta-analyses.” Annual publications between 1991 and 2014 increased 2,728% for systematic reviews and 2,635% for meta-analyses versus only 153% for all PubMed-indexed items. Currently, probably more systematic reviews of trials than new randomized trials are published annually. Most topics addressed by meta-analyses of randomized trials have overlapping, redundant meta-analyses; same-topic meta-analyses may exceed 20 sometimes. Some fields produce massive numbers of meta-analyses; for example, 185 meta-analyses of antidepressants for depression were published between 2007 and 2014. These meta-analyses are often produced either by industry employees or by authors with industry ties and results are aligned with sponsor interests. China has rapidly become the most prolific producer of English-language, PubMed-indexed meta-analyses. The most massive presence of Chinese meta-analyses is on genetic associations (63% of global production in 2014), where almost all results are misleading since they combine fragmented information from mostly abandoned era of candidate genes. Furthermore, many contracting companies working on evidence synthesis receive industry contracts to produce meta-analyses, many of which probably remain unpublished. Many other meta-analyses have serious flaws. Of the remaining, most have weak or insufficient evidence to inform decision making. Few systematic reviews and meta-analyses are both non-misleading and useful.

Conclusions
The production of systematic reviews and meta-analyses has reached epidemic proportions. Possibly, the large majority of produced systematic reviews and meta-analyses are unnecessary, misleading, and/or conflicted.

The Mass Production of Redundant, Misleading, and Conflicted Systematic Reviews and Meta-analyses.

Icmje

The aim of this study is to evaluate the validity of the use of digital models to assess tooth size, arch length, irregularity index, arch width and crowding versus measurements generated on hand-held plaster models with digital callipers in patients with and without malocclusion. Studies comparing linear and angular measurements obtained on digital and standard plaster models were identified by searching multiple databases including MEDLINE, LILACS, BBO, ClinicalTrials.gov, the National Research Register and Pro-Quest Dissertation Abstracts and Thesis database, without restrictions relating to publication status or language of publication. Two authors were involved in study selection, quality assessment and the extraction of data. Items from the Quality Assessment of Studies of Diagnostic Accuracy included in Systematic Reviews checklist were used to assess the methodological quality of included studies. No meta-analysis was conducted. Comparisons between measurements of digital and plaster models made directly within studies were reported, and the difference between the (repeated) measurement means for digital and plaster models were considered as estimates. Seventeen relevant studies were included. Where reported, overall, the absolute mean differences between direct and indirect measurements on plaster and digital models were minor and clinically insignificant. Orthodontic measurements with digital models were comparable to those derived from plaster models. The use of digital models as an alternative to conventional measurement on plaster models may be recommended, although the evidence identified in this review is of variable quality.

Orthodontic measurements on digital study models compared with plaster models: a systematic review

Objective: To evaluate the clinical differences in relation to the use of self-ligating brackets in orthodontics. Materials and Methods: Electronic databases were searched; no restrictions relating to publication status or language of publication were applied. Randomized controlled trials (RCTs) and controlled clinical trials (CCTs) investigating the influence of bracket type on alignment efficiency, subjective pain experience, bond failure rate, arch dimensional changes, rate of orthodontic space closure, periodontal outcomes, and root resorption were selected. Both authors were involved in study selection, validity assessment, and data extraction. Disagreements were resolved by discussion. Results: Six RCTs and 11 CCTs were identified. Meta-analysis of the influence of bracket type on subjective pain experience failed to demonstrate a significant advantage for either type of appliance. Statistical analysis of other outcomes was unfeasible because of inadequate methodological design and heteroge...

/pdf/self-ligating-brackets-in-orthodontics-a-systematic-review-1enmb85hkd.pdf

Self-ligating brackets in orthodontics. A systematic review.

Objectives To measure the self-reported frequency and severity of bullying amongst patients referred for orthodontic treatment and to investigate whether there is a relationship between levels of self-reported bullying, malocclusion and need for orthodontic treatment and an individual's self-esteem and oral health-related quality of life (OHRQoL). Design and setting Cross-sectional study of an adolescent group referred for orthodontic assessment at three UK hospitals. Subjects and methods Three hundred and thirty-six participants aged between 10 and 14 years were recruited. Validated questionnaires were used to measure the self-reported frequency and severity of bullying, self-esteem and OHRQoL. Orthodontic treatment need was assessed using IOTN. Results The prevalence of bullying was 12·8%. Being bullied was significantly associated with Class II Division 1 incisor relationship (P = 0·041),increased overbite (P = 0·023),increased overjet (P = 0·001)and a high need for orthodontic treatment assessed using AC IOTN (P = 0·014).Bullied participants also reported lower levels of social competence (P Conclusions Significant relationships exist between bullying and certain occlusal traits, self-esteem and OHRQoL.

/pdf/bullying-in-orthodontic-patients-and-its-relationship-to-5eccf6pvy4.pdf

Bullying in orthodontic patients and its relationship to malocclusion, self-esteem and oral health-related quality of life

How long does treatment with fixed orthodontic appliances last? A systematic review

Objective: To investigate the influence of radiographic position of palatally impacted canines on the length of treatment for orthodontic alignment. Materials and Methods: Treatment records of 45 consecutive successfully treated patients (36 unilateral, 9 bilateral) with ectopic palatal canines treated with surgical exposure and orthodontic traction were analyzed. The sample was based on orthodontic referrals over a 3-year period in Kent and Canterbury Hospital, UK. The duration of treatment was related to radiographic parameters including the height of the impacted canine, angulation of the long axis to the upper midline, mesiodistal position of the canine tip relative to the midline and adjacent incisors, and the anteroposterior position of the canine root apex. Results: Using multiple stepwise regression analysis, the horizontal position of the canine crown relative to adjacent teeth and maxillary dental midline showed a statistically significant correlation with the duration of treatment (P =...

/pdf/influence-of-radiographic-position-of-ectopic-canines-on-the-323twrp09w.pdf

Padhraig S. Fleming

Papers

Orthodontic measurements on digital study models compared with plaster models: a systematic review

Self-ligating brackets in orthodontics. A systematic review.

Bullying in orthodontic patients and its relationship to malocclusion, self-esteem and oral health-related quality of life

How long does treatment with fixed orthodontic appliances last? A systematic review

Influence of Radiographic Position of Ectopic Canines on the Duration of Orthodontic Treatment