Article type
Year
Abstract
Background: Individual participant data (IPD) meta-analysis (MA) enables nuanced effect modification analyses and may help standardize outcome measures across studies. However, there are multiple challenges to preparing IPD for MA, such as differences in outcome variables, differences in data collection methods, incomplete data dictionaries. These obstacles and others result in the consumption of extensive amounts of time and resources to prepare IPD for MA.
Objectives: The purpose of this tool is to describe a systematic approach to preparing data for IPD-MA analysis.
Methods: We reviewed relevant guidance from the Cochrane Handbook, Get Real-IPD working group, Cochrane Multiple Interventions group and other published literature. We developed a five-step approach to preparing IPD, through iterative consultation with the advisory board for an IPD-MA and systematic review.
Results: The five steps are: Processing, Replication, Imputation and Merging and Estimation (PRIME). The processing step verifies that the variables of interest are available in the original datasets, identifies missing values and relabels all variables of interests across the datasets to have common variable names. The replication step verifies that the processed dataset is consistent with the analyzed dataset in the published papers, using standardized differences. The imputation step involves an algorithm for how to handle datasets with missing values, including multiple imputation and merging of all imputed datasets. The merging step calls for combining all datasets after dealing with missing data. The final estimation step involves calculating any new variables required for analysis, such as categorical variables for gradations of intensity or severity of outcome variables. The outcomes and value of each of these five steps are illustrated using our systematic review and network meta-analysis of deworming for children.
Conclusion: The purpose of this guidance is to standardize the process of preparing data for IPD-MA. This guidance needs to be evaluated by application to other systematic reviews and meta-analyses.
Patient or healthcare consumer involvement: no
Objectives: The purpose of this tool is to describe a systematic approach to preparing data for IPD-MA analysis.
Methods: We reviewed relevant guidance from the Cochrane Handbook, Get Real-IPD working group, Cochrane Multiple Interventions group and other published literature. We developed a five-step approach to preparing IPD, through iterative consultation with the advisory board for an IPD-MA and systematic review.
Results: The five steps are: Processing, Replication, Imputation and Merging and Estimation (PRIME). The processing step verifies that the variables of interest are available in the original datasets, identifies missing values and relabels all variables of interests across the datasets to have common variable names. The replication step verifies that the processed dataset is consistent with the analyzed dataset in the published papers, using standardized differences. The imputation step involves an algorithm for how to handle datasets with missing values, including multiple imputation and merging of all imputed datasets. The merging step calls for combining all datasets after dealing with missing data. The final estimation step involves calculating any new variables required for analysis, such as categorical variables for gradations of intensity or severity of outcome variables. The outcomes and value of each of these five steps are illustrated using our systematic review and network meta-analysis of deworming for children.
Conclusion: The purpose of this guidance is to standardize the process of preparing data for IPD-MA. This guidance needs to be evaluated by application to other systematic reviews and meta-analyses.
Patient or healthcare consumer involvement: no