Search results for "Meta-Analysis as Topic"
showing 10 items of 86 documents
Known knowns and known unknowns on behavior change interventions and mechanisms of action.
2020
Systematic reviews and meta-analyses of research play an important role in summarizing current knowledge on the efficacy of the behavior change techniques and mechanisms of action that comprise behavioral interventions. The current reviews in the science of behavior change (SOBC) special issue represent a ‘step change’ in evaluating current evidence on behavior change interventions and mechanisms. This concluding article outlines the key findings and emerging issues identified in the reviews (‘known knowns’), and summarizes the evidence gaps highlighted by the reviews that need to be addressed in future research (‘known unknowns’). Specifically, findings of the reviews indicate that: tests …
Individual participant data systematic reviews with meta-analyses of psychotherapies for borderline personality disorder
2021
IntroductionThe heterogeneity in people with borderline personality disorder (BPD) and the range of specialised psychotherapies means that people with certain BPD characteristics might benefit more or less from different types of psychotherapy. Identifying moderating characteristics of individuals is a key to refine and tailor standard treatments so they match the specificities of the individual participant. The objective of this is to improve the quality of care and the individual outcomes. We will do so by performing three systematic reviews with meta-analyses of individual participant data (IPD). The aim of these reviews is to investigate potential predictors and moderating patient chara…
Flawed Meta-Analysis of Biodiversity Effects of Forest Management
2010
It appears that the negative effect of forest managementon biodiversity has become an axiom. Whether the neg-ative effect, however, is a fact based on solid empiricalevidence is not self-evident. Most of the studies that ad-dress the issue suffer from a lack of geographic extentand taxonomic narrowness. Therefore, a synthesis draw-ing together results from the individual studies is direlyneeded. In their recent paper, Paillet et al. (2010) rise tothis challenge and present a formal pan-European meta-analysis of data from 49 papers representing 120 indi-vidual comparisons across 10 taxonomic groups. Theirsynthesis has the potential to be a landmark paper inecological research, but also to af…
Genome-wide association analysis identifies six new loci associated with forced vital capacity
2014
Forced vital capacity (FVC), a spirometric measure of pulmonary function, reflects lung volume and is used to diagnose and monitor lung diseases. We performed genome-wide association study meta-analysis of FVC in 52,253 individuals from 26 studies and followed up the top associations in 32,917 additional individuals of European ancestry. We found six new regions associated at genome-wide significance (P <5 x 10(-8)) with FVC in or near EFEMP1, BMP6, MIR129-2-HSD17B12, PRDM11, WWOX and KCNJ2. Two loci previously associated with spirometric measures (GSTCD and PTCH1) were related to FVC. Newly implicated regions were followed up in samples from African-American, Korean, Chinese and Hispani…
Testing for homogeneity in meta-analysis I. The one-parameter case: standardized mean difference.
2010
Meta-analysis seeks to combine the results of several experiments in order to improve the accuracy of decisions. It is common to use a test for homogeneity to determine if the results of the several experiments are sufficiently similar to warrant their combination into an overall result. Cochran's Q statistic is frequently used for this homogeneity test. It is often assumed that Q follows a chi-square distribution under the null hypothesis of homogeneity, but it has long been known that this asymptotic distribution for Q is not accurate for moderate sample sizes. Here, we present an expansion for the mean of Q under the null hypothesis that is valid when the effect and the weight for each s…
Assessing covariate imbalance in meta-analysis studies.
2010
The main goal of meta-analysis is to combine data across studies or data sets to obtain summary estimates. In this paper, the novelty is to propose a statistical tool to assess a possible covariate imbalance in baseline variables to investigate similarity of trials. We conducted the detection of the covariate imbalance, first, through some graphical comparison of the empirical cumulative distribution functions or ECDFs, which are built by putting together arms or trials according to some risk factor, and second, through some non-parametric tests such as the Kolmogorov–Smirnov and the Anderson–Darling tests. To overcome the huge presence of ties, we conducted the statistical tests on perturbe…
Systematic Literature Reviews and Meta-Analyses
2009
SUMMARY Background: Because of the rising number of scientific publications, it is important to have a means of jointly summarizing and assessing different studies on a single topic. Systematic literature reviews, meta-analyses of published data, and meta-analyses of individual data (pooled reanalyses) are now being published with increasing frequency. We here describe the essential features of these methods and discuss their strengths and weaknesses. Methods: This article is based on a selective literature search. The different types of review and meta-analysis are described, the methods used in each are outlined so that they can be evaluated, and a checklist is given for the assessment of…
Scratching beneath 'The Scratching Case': systematic reviews and meta-analyses, the back door for evidence-based medicine
2014
Endometrial scratching or injury was first suggested a decade ago as a simple intervention to improve endometrial receptivity in patients undergoing ART. More than a decade later, based on weak evidence some doctors have adopted this strategy, although there is not yet agreement about its real benefit. In this opinion paper, we analyze the methodological and plausibility problem beneath 'the Scratching Case'. This is also applicable to several other examples of spurious associations reported in the literature. In particular, we emphasize what should be done so as not to dilute evidence-based medicine by a vicious circle created by the over-exploitation of inadequate or insufficient data to …
The ATXN1 and TRIM31 genes are related to intelligence in an ADHD background: evidence from a large collaborative study totaling 4,963 subjects
2010
Contains fulltext : 96400.pdf (Publisher’s version ) (Closed access) Intelligence is a highly heritable trait for which it has proven difficult to identify the actual genes. In the past decade, five whole-genome linkage scans have suggested genomic regions important to human intelligence; however, so far none of the responsible genes or variants in those regions have been identified. Apart from these regions, a handful of candidate genes have been identified, although most of these are in need of replication. The recent growth in publicly available data sets that contain both whole genome association data and a wealth of phenotypic data, serves as an excellent resource for fine mapping and …
Effect of using cardiovascular risk scoring in routine risk assessment in primary prevention of cardiovascular disease: an overview of systematic rev…
2019
Background Our objectives were to critically appraise and summarise the current evidence for the effectiveness of using cardiovascular disease (CVD) risk scoring (total risk assessment - TRA) in routine risk assessment in primary prevention of CVD compared with standard care with regards to patients outcomes, clinical risk factor levels, medication prescribing, and adverse effects. Methods We carried out an overview of existing systematic reviews (SRs). Presentation of the results aligned guidelines from the PRISMA statement. The data is presented as a narrative synthesis. We searched MEDLINE (Ovid), EMBASE, CENTRAL and SCOPUS databases from January 1990 to March 2017, reviewed the referenc…