Additionally, he covers how to perform subgroup metaanalysis and meta regression, and test for smallstudy effects. Comparing estimates of independent metaanalyses or. The objective of this metaanalysis was to assess the efficacy of spinal anesthesia sa vs. Assessment of the periodontal health status in patients.
Note that programs intended for statistical analysis of primary studies should not be used to perform these. See statas full list of official metaanalysis features stata users have also developed numerous excellent commands for performing metaanalyses. Software for statistical metaanalysis 175 finally, there are standalone packages for metaanalysis that come in many different flavors. If studies are divided into subgroups see section 9. We also performed subgroup, metaregression and sensitivity analyses. Comparing estimates of independent metaanalyses or subgroups. In other words, before jumping into a metaregression or subgroup analysis, you want to look at i2. Compute the mean effect and variance for each subgroup. As of stata 16, stata has an official suite of meta analysis commands. In metaanalysis we are working with subgroups of studies rather than groups of subjects, but will follow essentially the same approach, using a variant of the ttest. This is not an introduction to the use of stata software. For more advanced meta analyses like meta regression, multilevel and network meta analysis the. I run a meta analysis that included 15 observational studies, the overall heterogeneity for this sample was 71%, now i try to run a subgroup analysis to explain the source of this high.
Metaanalysis is well recognized as the most important study methodology in pharmacoepidemiology. Common components like forest plot interpretation, software that may be used, special cases for metaanalysis, such as subgroup. This module should be installed from within stata by typing ssc install ipdmetan. Jul 29, 2016 previous studies have demonstrated that gestational diabetes mellitus gdm and type 2 diabetes mellitus t2d share common genetic polymorphisms. However, at the moment the effect sizes have to be entered into the software beforehand jasp cannot calculate this for you. Subgroup analyses comprehensive metaanalysis software. Stata has two subpopulation options that are very flexible and easy to use. For more advanced metaanalyses like metaregression, multilevel and network metaanalysis the.
Comparing estimates of independent metaanalyses or subgroups suppose we have summary estimates e. Mar, 20 subgroup analysis is the process of comparing a treatment effect for two or more variants of an interventionto ask, for example, if an interventions impact is affected by the setting school versus community, by the delivery agent outside facilitator versus regular classroom teacher, by the quality of delivery, or if the longterm effect differs from the shortterm effect. Cochrans q test was significant at the 5% level of significance, while higginss i 2 was greater than 50%. You can summarize results from multiple studies with stata s new meta analysis suite. Moreover, it can be used for subgroupanalysis, moderator analysis, and publication bias analysis. With subgroup analysis or metaregression, you can explore heterogeneity of studies. Stata users have also developed numerous excellent commands for performing meta analyses. You can summarize results from multiple studies with statas new metaanalysis suite. Eligible studies were identified before january 2020 from. We describe what meta analysis is, what heterogeneity is, and how it affects meta analysis, effect size, the modeling techniques of meta analysis, and strengths and weaknesses of meta analysis.
Notes on subgroup analyses and metaregression meta. For a short overview of meta analysis in medcalc, see meta analysis. Jun 26, 2019 stata 16 introduces a new suite of commands for performing meta analysis. For example, studies in which allocation sequence concealment was adequate may yield different results from those in which it was inadequate. In meta analysis we are working with subgroups of studies rather than groups of subjects, but will follow essentially the same approach, using a variant of the ttest. More than 14 metaanalysis commands are now available in stata and these can perform a range of analyses. The new suite is broad, yet one of its strengths is its simplicity. Conflicting results identifying the association between tooth loss and cardiovascular disease and stroke have been reported. Genetic variants associated with gestational diabetes.
How can i analyze a subpopulation of my survey data in. Recommended softwarepackages for metaanalysis of diagnostic. Comparing estimates of independent meta analyses or subgroups suppose we have summary estimates e. Comprehensive metaanalysis single covariate only in cma 2. Of course, this presumes that there is any heterogeneity to be explained. The pooled hazard ratios hrs and 95% confidence intervals cis were calculated with stata 12. Meta analysis is a statistical technique for combining the results from several similar studies. Hi, i want to compare the effect of one variable var1 on dependent variable across two subgroups e. It is a userfriendly way of conducting stats without having to deal with the r code itself. Exponents personnel has expertise in statistical computing, utilizing a widevariety of software packages, including stata, sas, spss, comprehensive metaanalysis, metaanalysis mix, and episheet. Metaanalyses may be conducted in subgroups by using the by option.
Common components like forest plot interpretation, software that may be used, special cases for meta analysis, such as subgroup. For this workshop, we will be using the meta analysis commands that were introduced in stata 16. I was wondering if anyone can help with a subgroup analysis. Stata module for performing twostage ipd metaanalysis. Before you start collecting the actual data for the meta analysis, decide which statistical software package will be used to analyze the data.
We focus on those that are the most flexible and the most suited to the types of analyses carried out by ecologists and evolutionary biologists. With a metaregression, the predictors are at the level of the study, and the outcome is the effect size. Meta analysis is increasingly used as a key source of evidence synthesis to inform clinical practice. Previous studies have demonstrated that gestational diabetes mellitus gdm and type 2 diabetes mellitus t2d share common genetic polymorphisms. Metaanalysis was performed using the stata statistical software. The metaanalysis function of jasp is based on the aforementioned metafor r package. Jasp is a free, opensource program used to perform statistical analysis tests by using r packages. In practice, most metaanalyses are performed in general statistical packages or dedicated metaanalysis programs. The theory and statistical foundations of metaanalysis continually evolve, providing solutions to many new and challenging problems. For a standard metaanalysis which uses the mean, standard deviation, and sample size from both groups in a study, the following information is needed for every study. In practice, most meta analyses are performed in general statistical packages or dedicated meta analysis programs. Finally, 7 articles, including 368 patients, were included into our meta analysis.
If you assume that all studies in subgroup stem from the same population, and all have one shared true effect. See stata s full list of official meta analysis features. For small data it is possible to conduct it using manual calculation however that is not the case. Since then, the statistical methods evolved from simply following the approaches used for intervention meta analyses to the summary roc sroc model also known as moseslittenberg model which takes in to account the threshold effect, and then to more advanced. Cross validated is a question and answer site for people interested in statistics, machine learning, data analysis, data mining, and data visualization.
It has been almost 30 years since the publication of the first meta analysis of diagnostic test accuracy dta. The test of interaction for the above metaanalysis is presented at the bottom of the forest plot in the line with the title test for subgroup differences. The cause of heterogeneity of the effects among studies in the conventional meta analyses, has been typically analyzed by meta regression and sometimes by extracting several studies in a post hoc manner, constructing subgroups from these studies and analyzing the effect in this subgroup. In total, 12 eligible studies including 2749 patients were enrolled in the present metaanalysis. You can summarize results from multiple studies with stata s new metaanalysis suite. Rip copyprotected dvds with free software for windows 10, mac os x or linux duration.
The theory and statistical foundations of meta analysis continually evolve, providing solutions to many new and challenging problems. Perform fixedeffect and randomeffects metaanalysis using the meta and metafor packages. A total of 92 publications were initially retrieved using our search strategy. To conduct a metaanalysis in jasp, be sure to check our their guide. Analysis of two independent samples using stata software. Jul 29, 2016 in this study, we conducted a large scale meta analysis and further subgroup analysis of most gdm associated genetic variants whose pathogenesis is similar to those of t2d in order to confirm its genetic association and dissect the effects of ethnicity, sample size, ogtt criteria, maternal age, parity, bmi and genotyping methods on the association. Inguinal hernia repair is one of the most commonly performed surgical procedures. There are several different metaanalytic commands in stata, so without. Another approach would be to use eclplot another userwritten program. Does anyone have experience with subgroup plots in stata. In this chapter we show in detail how to use the statistical package stata both to perform a metaanalysis and. We describe what metaanalysis is, what heterogeneity is, and how it affects metaanalysis, effect size, the modeling techniques of metaanalysis, and strengths and weaknesses of metaanalysis. Or, we could use analysis of variance to assess the variance among groups means relative to the variance within groups. Select subgroup meta analysis from the analysis menu.
Differences between interaction and subgroup analysis. This section provides an example that illustrates how to perform a subgroup metaanalysis. Stata 16 introduces a new suite of commands for performing metaanalysis. If you read the linkedto thread above, you will see that david fisher had just written a series of commands for precisely that use amongst other things, namely to perform 2stage inversevariance individual participant data metaanalysis. To date, there is no consensus on which anesthesia should be used. Introduction to metaanalysis using stata colloquium. Use funnel plots and formal tests to explore publication bias and smallstudy effects. As of stata 16, stata has an official suite of metaanalysis commands. Performing subgroup analysis using the metafor package. In metaanalysis we are working with subgroups of studies rather than groups of subjects, but will follow essentially the same approach, using a variant of the ttest oravariantofanalysisofvariancetocomparethesubgroupmeans. Do not pool data using metaanalysis this may produce misleading results if there is high heterogeneity, or 2.
Studentst test is the most popular statistical test. Therefore, a doseresponse metaanalysis was performed to clarify and quantitatively assess the correlation between tooth loss and cardiovascular disease and stroke risk. I was wondering if anyone can help with a subgroup. Notes on subgroup analyses and metaregression metaanalysis. Subgroup analyses comprehensive metaanalysis software cma. Dec 19, 2011 rip copyprotected dvds with free software for windows 10, mac os x or linux duration. Since then, the statistical methods evolved from simply following the approaches used for intervention metaanalyses to the summary roc sroc model also known as moseslittenberg model which takes in to account the threshold effect, and.
The prognostic value of serum amyloid a in solid tumors. Meta analysis was performed using the stata statistical software. Metaregression models can be used to analyse associations between treatment effect and study characteristics. Tooth loss and risk of cardiovascular disease and stroke. Essentials are that it lacks capabilities for more advanced analyses, such as general linear models, network meta. In the following sections we provide an example of fixed and random effects metaanalysis using the metan command. Meta analysis is well recognized as the most important study methodology in pharmacoepidemiology. This section provides an example that illustrates how to perform a subgroup meta analysis. Use randomeffects, fixedeffects, or commoneffect meta analysis to combine individual results and compute overall effect size. Metaanalysis is a statistical technique for combining the results from several similar studies. I was wondering if anyone can help with a subgroup analysis in stata. The purpose of the metaregression is to explain the heterogeneity.
See below for more on planning subgroup analyses, or 3. The knapphartung method involves two modifications to the standard error for the randomeffects model. Assess the impact of publication bias on results with trimandfill analysis. The historical roots of meta analysis can be traced back to 17th century studies of astronomy, while a paper published in 1904 by the statistician karl pearson in the british medical journal which collated data from several studies of typhoid inoculation is seen as the first time a meta analytic approach was used to aggregate the outcomes of multiple clinical studies. A handson practical tutorial on performing metaanalysis with stata. Finally, 7 articles, including 368 patients, were included into our metaanalysis. Investigate heterogeneity using subgroup analysis or meta regression.
Up to march 2017, seventeen cohort studies were included in current meta. The historical roots of metaanalysis can be traced back to 17th century studies of astronomy, while a paper published in 1904 by the statistician karl pearson in the british medical journal which collated data from several studies of typhoid inoculation is seen as the first time a metaanalytic approach was used to aggregate the outcomes of multiple clinical studies. An updated collection from the stata journal, second edition, which brought together all the stata journal. Stata has a long history of metaanalysis methods contributed by stata researchers, for instance, palmer and sterne 2016. An updated collection from the stata journal, second edition by tom m. One way is to run the same regression model separately for each group and test the differences between these two. I know that there is an automated way to define subgroups based on factor. In this study, we conducted a large scale metaanalysis and further subgroup analysis of most gdm associated genetic variants whose pathogenesis is similar to those of t2d in order to confirm its genetic association and dissect the effects of ethnicity, sample size, ogtt criteria, maternal age, parity, bmi and genotyping methods on the association. Using the subpopulation options is extremely important when analyzing survey data. For dichotomous data, the metan command needs four input variables metan rh fh rp fp typing this, the software gives you the summary rr of haloperidol versus placebo using the.
If you read the linkedto thread above, you will see that david fisher had just written a series of commands for precisely that use amongst other things, namely to perform 2stage inversevariance individual participant data meta analysis. How can i analyze a subpopulation of my survey data in stata. Software some of the programs developed for meta analysis are able to perform subgroup analysis as well as meta regression see chapter 44. The test compares two mean values to judge if they are different or not. The cause of heterogeneity of the effects among studies in the conventional metaanalyses, has been typically analyzed by metaregression and sometimes by extracting several studies in a post hoc manner, constructing subgroups from these studies. Researchers would need to use statistical software and packages to conduct their analysis. Essentials, which functions as a set of spreadsheet workbooks. It has been almost 30 years since the publication of the first metaanalysis of diagnostic test accuracy dta. Software some of the programs developed for metaanalysis are able to perform subgroup analysis as well as metaregression see chapter 44. With subgroup analysis or meta regression, you can explore heterogeneity of studies.
I run a metaanalysis that included 15 observational studies, the overall heterogeneity for this sample was 71%, now i try to run a subgroup analysis to explain the source of this high. Moreover, it can be used for subgroup analysis, moderator analysis, and publication bias analysis. In subgroup metaanalysis or simply subgroup analysis, the studies are. Tackle heterogeneity using subgroup analyses and metaregression. Stata now offers the new suite of commands, meta, to perform metaanalysis. Stata module for performing twostage ipd metaanalysis, statistical software components s457785, boston college department of economics, revised 04 feb 2019. Select subgroup metaanalysis from the analysis menu.
Look at the help file for the command that you will be using. The flow chart of search history is presented in fig. Use randomeffects, fixedeffects, or commoneffect metaanalysis to combine individual results and compute overall effect size. His stata package is ipdmetan and is available by typing ssc install ipdmetan. This point is rather straightforward, as the same criteria as the ones for a simple metaanalysis without subgroups see chapter 4 and chapter 4. Chapter 7 subgroup analyses doing metaanalysis in r. Saurav, could you please share the do code for subgroup analysis of meta on stata. Note that if this is a possibility, it needs to be planned and prespecified at protocol stage. Exponent scientists have conducted a wide variety of scientific assessments that rely upon metaanalysis methodology. If the data set is subset, meaning that observations not to be included in the subpopulation are deleted from the data set, the standard errors of the estimates cannot be calculated. A handson practical tutorial on performing metaanalysis. Among the final 1,018 eligible publications for our metaanalysis fig. Of these publications, 21 were included in the current metaanalysis 3050.
Check if selective outcome reporting publication bias or p. For a short overview of metaanalysis in medcalc, see metaanalysis. For example, studies in which allocation sequence concealment was adequate may yield different results from those in. An updated collection from the stata journal, second edition, which brought. Subgroup analysis is the process of comparing a treatment effect for two or more variants of an interventionto ask, for example, if an interventions impact is affected by the setting school versus community, by the delivery agent outside facilitator versus regular classroom teacher, by the quality of delivery, or if the longterm effect differs from the short.
Comparison of spinal anesthesia and general anesthesia in. Metaanalysis is increasingly used as a key source of evidence synthesis to inform clinical practice. The tool can be downloaded from the accompanying website. The module is made available under terms of the gpl v3.
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