Random main effects of treatment: A case study with a network meta-analysis

2019 ◽  
Vol 61 (2) ◽  
pp. 379-390 ◽  
Author(s):  
Stephen Senn ◽  
Susanne Schmitz ◽  
Anna Schritz ◽  
Samir Salah
Keyword(s):  
Meta Analysis ◽  
Main Effects

scholarly journals The research method of conceptual frameworks. The case of Pygmalion effect: A leadership style or self-fulfilling prophecy?

2019 ◽  
Vol 9 (3) ◽  
pp. 487-510
Author(s):  
Sejla Almadi
Keyword(s):  
Leadership Style ◽  
Meta Analysis ◽  
Educational Technology Research ◽  
Research Subject ◽  
Conceptual Frameworks ◽  
Pygmalion Effect ◽  
Less Is More ◽  
Database Research ◽  
The Subject

Conceptual frameworks are conjectural/hypothetical research tools that are particularly important and widely used in the disciplined inquiry, including educational (technology) research. However, there is a lack of guidance on how to construct them. Hence, the objective of the current research was to provide a methodological perspective through a case study on how to develop such a framework for deductive research with a complex research subject. To this end, a five-step technique was constructed and implemented: text database, research panorama, authors’ network and thread, location, and definition. The case of Pygmalion effect was actual and significant as a recent meta-analysis found it to have an outstanding impact, among other leadership interventions, and relevant to educational research as it was first experimented in educational context. The conclusion found the five steps to be intertwined as they were built upon each other, carried the thread forward and opened it up deeper and closer to the research subject by each section. The errors and limitations involved uniqueness, availability, less is more, meaningfulness, approach, and space. Hence, the recommendations were defined as the regard for the complexity of the research subject and the approach to which the defined steps were delegated, the preliminary search on the most up-to-date academic papers on the subject, the only necessary number of collected sources and classes, the sense-making in implementing the steps, and the adaptation to longer essays, theses, or to prepare the foundation of research proposals.

A Simple, Principled Approach to Combining Evidence From Meta-Analysis and High-Quality Replications

2018 ◽  
Vol 1 (2) ◽  
pp. 174-185 ◽  
Author(s):  
Evan C. Carter ◽  
Michael E. McCullough
Keyword(s):  
Meta Analysis ◽  
Ego Depletion ◽  
Practical Significance ◽  
High Quality ◽  
Questionable Research Practices ◽  
Combining Evidence ◽  
Meta Analyses ◽  
Work Done ◽  
Combining Information

Recent discussions of the influence of publication bias and questionable research practices on psychological science have increased researchers’ interest in both bias-correcting meta-analytic techniques and preregistered replication. Both approaches have their strengths: For example, meta-analyses can quantitatively characterize the full body of work done in the field of interest, and preregistered replications can be immune to bias. Both approaches also have clear weaknesses: Decisions about which meta-analytic estimates to interpret tend to be controversial, and replications can be discounted for failing to address important methodological heterogeneity. Using the experimental literature on ego depletion as a case study, we illustrate a principled approach to combining information from meta-analysis with information from subsequently conducted high-quality replications. This approach (a) compels researchers to explicate their beliefs in meta-analytic conclusions (and also, when controversy arises, to defend the basis for those beliefs), (b) encourages consideration of practical significance, and (c) facilitates the process of planning replications by specifying the sample sizes necessary to have a reasonable chance of changing the minds of other researchers.

Diagnostic Meta-Analysis: Case Study in Surgery

2018 ◽  
pp. 285-302
Author(s):  
Eliana Al Haddad ◽  
Hutan Ashrafian ◽  
Thanos Athanasiou
Keyword(s):  
Meta Analysis

Diagnostic Meta-Analysis: Case Study in Oncology

2018 ◽  
pp. 263-284
Author(s):  
Sulbaran Marianny ◽  
Sousa Afonso ◽  
Bustamante-Lopez Leonardo
Keyword(s):  
Meta Analysis

Diagnostic Meta-Analysis: Case Study in Gastroenterology

2018 ◽  
pp. 249-261
Author(s):  
Bashar J. Qumseya ◽  
Michael Wallace
Keyword(s):  
Meta Analysis

scholarly journals Treatment sequence network meta-analysis in Crohn’s disease: a methodological case study

2019 ◽  
Vol 35 (5) ◽  
pp. 733-756 ◽  
Author(s):  
Abhishek Varu ◽  
Florence R. Wilson ◽  
Peter Dyrda ◽  
Maureen Hazel ◽  
Brian Hutton ◽  
...  
Keyword(s):  
Crohn’S Disease ◽  
Crohn's Disease ◽  
Meta Analysis ◽  
Treatment Sequence

scholarly journals Additional Search Strategies May Not Be Necessary for a Rapid Systematic Review

2015 ◽  
Vol 10 (2) ◽  
pp. 150
Author(s):  
Joanne L. Jordan
Keyword(s):  
Systematic Review ◽  
Systematic Reviews ◽  
Reference Lists ◽  
Meta Analysis ◽  
Search Strategies ◽  
Risk Of Bias ◽  
Chronic Depression ◽  
Randomized Controlled ◽  
Central Database

A Review of: Westphal, A., Kriston, L., Hölzel, L.P., Härter, M., & von Wolff, A. (2014). Efficiency and contribution of strategies for finding randomized controlled trials: a case study from a systematic review on therapeutic interventions of chronic depression. Journal of Public Health Research, 3(2), 177. doi: 10.4081/jphr.2014.177 Abstract Objective – To evaluate the efficiency and contribution of additional searching strategies for finding randomized controlled trials (RCTs) in a systematic review. Design – A methodological case study. Setting – Biomedical literature. Methods – A sensitive search (defined as “the ratio of the number of relevant reports identified to the total number of relevant reports in existence”) was conducted of electronic databases, Cochrane CENTRAL database, MEDLINE, EMBASE, PsycInfo, CINAHL, BIOSIS, and Web of Science databases (Science and Social Science Citation Indexes). The following additional searching strategies were conducted: hand-searching contents of relevant journals (Archives of General Psychiatry, Journal of Consulting and Clinical Psychology, and Journal of Affective Disorders), citation tracking (forwards tracking using Social Science and Science Citation Index and backwards tracking by looking through reference lists of included studies), screening reference lists of relevant systematic reviews, searching clinical trials registers (ClinicalTrials.gov and ICTRP registers), and contacting first authors of included studies to find any similar unpublished studies. The number of articles identified by each of these methods was recorded and screened for inclusion in the systematic review. The authors calculated what they labelled as the ‘efficiency’ of each searching strategy (the number of included studies identified by the search method as a proportion of the full text articles screened) and the ‘contribution’ of the search strategies (the ratio of included studies identified by that method to the final number of included studies in the systematic review). The methodological quality of each included study was assessed using the Cochrane Risk of Bias Tool, which is a critical appraisal checklist used to judge the study’s value in the systematic review. The meta-analysis in the systematic review was conducted with and without the studies identified by the additional searching strategies to assess their impact on the review’s findings. Main Results – In total 50 studies were identified, 42 from electronic database searches and 8 from additional search strategies. As illustrated by the results in Table 1, the most useful additional search strategy was screening reference lists of relevant systematic reviews. Journal hand-searching and contacting authors also contributed to the review. Of the eight studies identified by the additional search strategies none were judged to have a low risk of bias (four had high risk of bias and four were unclear). Of the 42 included studies from electronic searches only 11 were judged to have a low risk of bias, whereas 9 studies had a high risk of bias and 22 were unclear. Excluding the eight studies retrieved from additional search strategies in the systematic review meta-analysis did not influence the results on the effectiveness of the different interventions for chronic depression. These studies were found to be indexed correctly on the electronic databases, but were not identified in the initial search. Conclusion – Additional search strategies, especially screening reference lists of systematic reviews and hand-searching relevant journals, retrieved a substantial number of relevant studies for a systematic review of interventions for treating chronic depression. However, results of the review’s meta-analysis did not differ when these additional studies (rated as either high or unclear risk of bias) were not included and search methods were time consuming. It might be reasonable to rely on electronic searching strategies when resources for conducting a systematic review are limited or when doing a “rapid review.” The benefits and limitations of additional search strategies should be considered particularly when resources or time for conducting a systematic review are limited. If the electronic database search is sensitive and includes the Cochrane CENTRAL database additional search strategies may not be necessary, but these findings should be tested in other research areas.

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