Definitions for

**"Meta-analysis"****Related Terms:**Quantitative research, Biostatistics, External validity, Case studies, Generalizability, Descriptive study, Observational study, Cross-sectional study, Experimental design, Survey research, Qualitative research, Case study, Replication, Selection bias, Analysis, Internal validity, Qualitative methods, Statistician, Biometry, Descriptive research, Experimental research, Statistical analysis, Analysis, Sampling, Prospective study, Convenience sample, Experiment, Triangulation, Comparative method, Qualitative, Survey , Cohort study, Scientific, Design of experiments, Pilot test, Empirical research, Quasi-experimental design, Statistical inference, Retrospective study, Bias, Doe, Critical appraisal, Profiling, Sample survey, Comparison group, Hypothesis testing, Inferential statistics, Retrospective analysis, Pilot study, Demography

A quantitative summary of several individual studies examining the same question. The purpose is to obtain statistical confirmation of results and conclusions, e. g. for the generalization of statements.

( Appendix G) The systematic, organised, and structured evaluation of a problem of interest using information from all relevant independent randomised trials. It includes a qualitative component (application of predetermined criteria of scientific rigour, eg Appendix B) and a quantitative component (statistical combination of the data which can be pooled).

(met´a-a-nal´i-sis): The process of using statistical methods to combine the results of different studies; systematic, organized, and structured evaluation of a problem using information, commonly in the form of statistical tables, etc., from a number of different studies of the problem.

Pooled statistical analysis of results from several individual statistical analyses of different experiments, searching for statistical significance which is not possible within the smaller sample sizes of individual studies.

an overall analysis of many articles on the same subject

Meta-analysis is essentially synthesis of available literature about a topic. Ideally, synthesis of randomized trials to arrive at a single summary estimate is used. Other types of studies are used for meta-analysis as well.

A statistical technique that estimates the impact of a treatment or variable across a set of related investigations.

Statistical procedure for integrating the results of different studies.

A statistical method for pooling the results of separate studies to obtain a summary estimate of the relationship between exposure and outcome variables.

A statistical technique which allows an overview of all studies which have considered a particular issue.

A quantitative method of analyzing and comparing various therapies by standardizing their results.

A systematic review that uses quantitative methods to summarise the results. This may be achieved in several ways. Examples on diagnosis of diabetes and head injury are interesting.

A statistical review of the results of several clinical trials

A statistical synthesis of data from separate but similar (i.e., comparable) studies, leading to a quantitative summary of pooled results.

a statistical process for pooling data from many clinical trials to glean a clear answer

A statistical technique which allows the results of a number of studies to be combined and a type of average result to be derived. The technique allows studies to be given different weightings depending, often, upon their size and quality of design

A statistical technique for combining the results of many studies even when the studies used different methods to collect the data. This technique has been useful in studies on the outcome of psychotherapy.

a study of other studies about a particular topic of interest.

A statistical technique to combine information from many empirical studies on a topic to objectively estimate the reliability and overall size of the effect.

The systematic analysis of a set of existing evaluations of similar programs in order to draw general conclusions, develop support for hypotheses, and/or produce an estimate of overall program effects.

The process of combining the results of several related studies to obtain more reliable conclusions.

A method of reviewing literature that involves statistically comparing or combining the results of related studies.

The systematic study of numerous research outcomes to determine the patterns that are common to them, not apparent when one focuses on a few studies.

is a systematic review or overview which uses quantitative methods to summarise the results.

A review of a focused clinical question following rigorous methodological criteria and employing statistical techniques to combine data from independently performed studies on that question. To learn more, see the User’s Guide.

a combination of many different trial results designed to increase the reliability of research by combining and analyzing the results of all known trials of the same product or experiments on the same subject

a compilation of many smaller studies done of the same thing, all meeting the same basic study criteria

a compilation of results achieved in many randomized clinical trials

a less biased way of combining results across studies and figuring out what they say collectively, than previous methods are, because it applies a rule that is independent of the author's assumptions and hopes for the outcome

a mathematical method used to compare the results of similar studies

a mathematical synthesis of the results of two or more primary studies

a means of combining results from more than one trial to look for overall trends

a method for combining the results of a collection of individual studies, taking into account the number of subjects who participated in each study and the size of the obtained effect

a method of compiling and comparing the results of numerous research studies without actually performing any new field research

a method of statistically combining the results of a set of independent studies that test the same hypothesis and using inferential statistics to draw conclusions about the overall result of the studies

an attempt to look at every quality study that addresses a particular subject

a quantitative analysis of a sample of existing research studies on a particular topic

a quantitative overview which yields the best estimate of the treatment effect by pooling results from different trials

a relatively new statistical technique which combines the data from several clinical trials that all address a particular clinical question, in an attempt to estimate an overall answer to that question

a review and summary of the results of many clinical studies on the same subject

a review that includes a statistical analysis of data combined from many

a set of scientific statistical procedures used to combine results across studies in order to more accurately test specific hypotheses

a statistical analysis of the results of other analyses

a statistical method combining research from different published studies in order to re-examine the overall results

a statistical method combining results from published studies in order to re-examine the overall evidence

a statistical method for analyzing the results of multiple research studies

a statistical method of combining results from separate studies in order to derive overall conclusions about a question or hypothesis

a statistical method that combines findings from previous studies in order to re-examine overall results

a statistical method that combines findings from studies in order to re-interpret the overall results

a statistical method that combines previously published study results in order to interpret their overall findings

a statistical method that combines results from published studies in order to examine their findings overall

a statistical method that combines results from similar published studies in order to re-interpret all the evidence

a statistical pooling of already published research papers

a statistical practice of combining the results of a number of studies

a statistical procedure for combining a number of existing studies

a statistical procedure that allows researchers to combine the results of many different experimental findings

a statistical technique that allows researchers to combine results from separate but related studies

a study of all the published literarture on a particular subject(within certain defined parameters for the analysis, ie all double-blind randomised studies, ect

a study that pools the data from many other related studies to form a conclusion about a particular research question

a study which combines the results of other studies (usually drawn from the published literature) and synthesize their summaries and conclusions

a summary of multiple studies evaluating the same type of treatment

a summary of previous research that uses quantitative methods to compare outcomes across a wide range of studies

a systematic quantitative review of original research studies of some phenomenon, such as the effect of a specific treatment on some aspect of health or behavior

a thorough, hard-nosed, expert review of the literature, with the aim of identifying the best-conducted studies in terms of scientific method and overall credibility

a tool for aggregating and evaluating research data from a

a type of data analysis in which the results of several studies, none of which need find anything of statistical significance, are lumped together and analyzed as if they were the results of one large study

a type of systematic review that uses statistical methods to

a unified statistical analysis of results from many individual studies for the purpose of integrating their findings and drawing additional conclusions from their data

a way of combining results from multiple studies

a way of combining the results of a group of similar studies on the same subject

A rigorous statistical method of combining the results of several studies to obtain more reliable estimates of the effects of a general type of treatment or intervention; can be used to summarize program evaluation and draw overall conclusions about the strength and consistency of the influence, or effect size, that particular types of programs have on violence.

A statistical technique that combines the results of two or more studies of similar design; the statistical analysis of a large collection of results from individual studies for the purpose of integrating the findings. Integrating the study findings results in a larger sample size (number of study participants) than the sample size of each individual study, which may add to the statistical significance (see statistical significance) and generalizability (see generalizability) of the findings. The conclusions that can be drawn based on the data of a meta-analysis may be limited by such factors as differences in the designs of the individual studies being combined.

A statistical technique which summarizes the results of several studies into a single estimate of their combined result. It is a key element of many systematic reviews.

is where data from a number of studies are lumped together in order to provide evidence for or against a hypothesis. See also: Cancer Statistics

A statistical process for pooling data from many clinical trials and summarizing it through formal statistical means. Also called overview.

Combining the results from several different epidemiological studies into a single result

Process of using statistical methods to combine the results of different studies. A frequent application is pooling the results from a set of randomized controlled trials, none of which alone is powerful enough to demonstrate statistical significance.

A way of grouping information or data from a number of different studies to determine an average or common effect. It is aimed at improving the precision of the available data by looking at a greater number of people. It may not be possible for a meta-analysis to be included in a review because data from different studies cannot always be combined.

systematic methods that use statistical techniques for combining results from different studies to obtain a quantitative estimate of the overall effect of a particular intervention or variable on a defined outcome. This combination may produce a stronger conclusion than can be provided by any individual study. (Also known as data synthesis or quantitative overview.)

Describes when statistical techniques are used to combine the results of a number of studies about the same topic. Meta-analysis is often used as part of a systematic review, that uses an explicit approach to identify, select and appraise relevant studies. The studies are then collectively analysed to give pooled results (as opposed to the ?ndings of a single study).

a category of analytical procedures which involve combining results from many different individual studies. The advantage of a meta-analysis over a single study is that the meta-analysis is based upon a much larger sample (the combined samples of all of the individual studies included in the analysis) and therefore is typically interpreted as a more robust assessment of validity.

The process of synthesizing research results by selecting and combining results from previous separate but related studies.

statistical method that combines results from many studies.

A technique for combining the results of several studies for the purpose of determining the net effects of related factors or treatments on a process or disease.

A statistical analysis of data combined from two or more studies.

An overview in which quantitative methods are used to summarise the results of several studies on a single topic. A meta-analysis is used in an attempt to gain greater objectivity, generalisability and precision by including all the available high quality evidence from randomised controlled trials carried out on a specified topic.

A set of statistical procedures used to review a body of evidence by combining the results of individual studies to measure the overall reliability and strength of particular effects.

is an overview which uses quantitative methods to summarize the results.

A method for the statistical re-analysis of experimental and correlational results from independent studies that address related research questions.

This is a systematic review that employs statistical methods to combine and summarise the results of several studies, giving more weight to the most reliable studies.

This is a way to evaluate the results of several similar trials by adding together the results from all of the trials. The idea is that if one trial gives an answer and many trials evaluated together give the same answer, it is likely that the answer is correct.

systematic review that combines and analyses findings from pre-existing studies; providing a summary or synthesis of an area of research.

Pooling and examining data from a number of studies

An analytical method that combines similar experiments in a field (originally used in psychotherapy and behavioral sciences) to determine if the collective results obtained by various independent researchers demonstrates a real and quantifiable effect; this method has been extremely successful in proving that the results of many parapsychological experiments are genuine and cannot be easily dismissed as chance, incompetence, or fraud.

Meta-analysis is a statistical technique which summarises the results of several studies into a single estimate, giving more weight to results from larger studies.

A quantitative technique in which the results of several individual studies are pooled to yield overall conclusions.

A statistical method that pools the results from multiple similar experiments, hoping that the improved power obtained from the combined data sets will identify statistically significant patterns that cannot be identified within the smaller sample sizes of individual studies.

a method of summarizing previous research by reviewing and combining results from multiple CLINICAL TRIALS. Meta-analyses are attempted when previous studies were too small individually to achieve meaningful or statistically significant results. Because combining data from disparate groups is problematic, meta-analyses usually are considered more suggestive than definitive.

is a review that uses quantitative methods to combine the statistical measures from two or more studies and generates a weighted average of the effect of an intervention, degree of association between a risk factor and a disease, or accuracy of a diagnostic test.

A quantitative statistical method to pool trial data in a single estimate. Can be part of a systematic review.

a method for combining the results of several independent studies that measure the same outcomes so that an overall summary statistic can be calculated.

The process or technique of synthesizing multiple research results by using various statistical methods to retrieve, select, and combine results from previous separate yet related studies to test a hypothesis.

a technique that combines the results of many similar studies to determine the size and consistency of the effect of a particular kind of independent variable. (56)

A mathematical or statistical analysis, used to pool the results of all studies investigating a particular effect (e.g., the effect of folic acid supplementation on homocysteine levels) and provide an overall estimate of that effect.

A method for combining the results from several independent studies of the same outcome so that an overall P-value may be determined.

A type of research review that uses statistical techniques to analyze results from a collection of individual studies.

A methodical review of the results of multiple research studies. In a meta-analysis, statistical methods are used to measure the combined results of these studies and estimate an overall effect.

a statistical technique used to determine the effect of a treatment; it is based on data pooled from multiple clinical studies.

A statistical technique that treats the accumulated studies of a particular phenomenon as a single grand experiment and each study as a single observation.

In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. The first meta-analysis was performed by Karl Pearson in 1904, in an attempt to overcome the problem of reduced statistical power in studies with small sample sizes; analyzing the results from a group of studies can allow more accurate data analysis.