
Covariate assembly using FeatureExtraction
buildMRCovariates.RdLeverages the OHDSI FeatureExtraction package to assemble a rich covariate object from OMOP CDM data. This object serves two purposes: (1) providing covariates for the outcome model to control for confounders and population stratification, and (2) exposing the full phenome for the instrument PheWAS diagnostic that checks for pleiotropic associations.
If ancestry principal components (PCs) are available, they are merged into the covariate matrix. Ancestry PCs are critical for controlling population stratification in genetic association studies.
Usage
buildMRCovariates(
connectionDetails,
cdmDatabaseSchema,
cohortDatabaseSchema,
cohortTable,
outcomeCohortId,
covariateSettings = NULL,
ancestryPCsTable = NULL,
ancestryPCsSchema = NULL,
numAncestryPCs = 10
)Arguments
- connectionDetails
A
DatabaseConnector::connectionDetailsobject.- cdmDatabaseSchema
Character. Schema containing OMOP CDM tables.
- cohortDatabaseSchema
Character. Schema containing the cohort table.
- cohortTable
Character. Name of the cohort table.
- outcomeCohortId
Integer. Cohort definition ID for the outcome.
- covariateSettings
A FeatureExtraction covariate settings object. If NULL (default), uses
createDefaultMRCovariateSettings.- ancestryPCsTable
Character or NULL. Name of a table containing person_id and ancestry principal components (PC1 through PC_K). If NULL, ancestry PCs are not included.
- ancestryPCsSchema
Character or NULL. Schema containing the ancestry PCs table.
- numAncestryPCs
Integer. Number of ancestry PCs to include (1 through this value). Default is 10.
Value
A list with class "medusaCovariateData" containing:
- covariateData
The FeatureExtraction covariate object returned by
getDbCovariateData(). Its main tables arecovariateData$covariatesandcovariateData$covariateRef.- ancestryPCs
Data frame of ancestry PCs if provided, NULL otherwise.
- settings
The covariate settings object used.
Details
Assemble Covariate Matrix for Mendelian Randomization
Default covariate settings include: conditions in 365-day lookback (binary), drug exposures in 365-day lookback (binary), most recent measurement values, and demographics (age group, sex, index year). These are assembled using standard FeatureExtraction covariate setting objects.