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CDMConnector

Are you using the tidyverse with an OMOP Common Data Model?

Interact with your CDM in a pipe-friendly way with CDMConnector.

  • Quickly connect to your CDM and start exploring.
  • Build data analysis pipelines using familiar dplyr verbs.
  • Easily extract subsets of CDM data from a database.

Overview

CDMConnector introduces a single R object that represents an OMOP CDM relational database inspired by the dm, DatabaseConnector, and Andromeda packages. The cdm objects encapsulate references to OMOP CDM tables in a remote RDBMS as well as metadata necessary for interacting with a CDM, allowing for dplyr style data analysis pipelines and interactive data exploration.

Features

CDMConnector is meant to be the entry point for composable tidyverse style data analysis operations on an OMOP CDM. A cdm_reference object behaves like a named list of tables.

  • Quickly create a list of references to a subset of CDM tables
  • Store connection information for later use inside functions
  • Use any DBI driver back-end with the OMOP CDM

See Getting started for more details.

Installation

CDMConnector can be installed from CRAN:

install.packages("CDMConnector")

The development version can be installed from GitHub:

# install.packages("devtools")
devtools::install_github("darwin-eu/CDMConnector")

Usage

Create a cdm reference from any DBI connection to a database containing OMOP CDM tables. Use the cdm_schema argument to point to a particular schema in your database that contains your OMOP CDM tables and the write_schema to specify the schema where results tables can be created, and use cdm_name to provide a name for the database.

library(CDMConnector)

con <- DBI::dbConnect(duckdb::duckdb(dbdir = eunomiaDir()))

cdm <- cdmFromCon(con = con, 
                  cdmSchema = "main", 
                  writeSchema = "main", 
                  cdmName = "my_duckdb_database")

A cdm_reference is a named list of table references:

library(dplyr)
names(cdm)
##  [1] "person"                "observation_period"    "visit_occurrence"     
##  [4] "visit_detail"          "condition_occurrence"  "drug_exposure"        
##  [7] "procedure_occurrence"  "device_exposure"       "measurement"          
## [10] "observation"           "death"                 "note"                 
## [13] "note_nlp"              "specimen"              "fact_relationship"    
## [16] "location"              "care_site"             "provider"             
## [19] "payer_plan_period"     "cost"                  "drug_era"             
## [22] "dose_era"              "condition_era"         "metadata"             
## [25] "cdm_source"            "concept"               "vocabulary"           
## [28] "domain"                "concept_class"         "concept_relationship" 
## [31] "relationship"          "concept_synonym"       "concept_ancestor"     
## [34] "source_to_concept_map" "drug_strength"

Use dplyr verbs with the table references.

cdm$person %>% 
  tally()
## # Source:   SQL [?? x 1]
## # Database: DuckDB 1.4.3 [root@Darwin 23.1.0:R 4.5.1//private/var/folders/2j/8z0yfn1j69q8sxjc7vj9yhz40000gp/T/RtmpnaikmI/file7e465691e16.duckdb]
##       n
##   <dbl>
## 1  2694

Compose operations with the pipe.

cdm$condition_era %>%
  left_join(cdm$concept, by = c("condition_concept_id" = "concept_id")) %>% 
  count(top_conditions = concept_name, sort = TRUE)
## # Source:     SQL [?? x 2]
## # Database:   DuckDB 1.4.3 [root@Darwin 23.1.0:R 4.5.1//private/var/folders/2j/8z0yfn1j69q8sxjc7vj9yhz40000gp/T/RtmpnaikmI/file7e465691e16.duckdb]
## # Ordered by: desc(n)
##    top_conditions                               n
##    <chr>                                    <dbl>
##  1 Viral sinusitis                          17268
##  2 Acute viral pharyngitis                  10217
##  3 Acute bronchitis                          8184
##  4 Otitis media                              3561
##  5 Osteoarthritis                            2694
##  6 Streptococcal sore throat                 2656
##  7 Sprain of ankle                           1915
##  8 Concussion with no loss of consciousness  1013
##  9 Sinusitis                                 1001
## 10 Acute bacterial sinusitis                  939
## # ℹ more rows

And much more besides. See vignettes for further explanations on how to create database connections, make a cdm reference, and start analyzing your data.

Getting help

If you encounter a clear bug, please file an issue with a minimal reproducible example on GitHub.

Citation

## To cite package 'CDMConnector' in publications use:
## 
##   Black A, Gorbachev A, Burn E, Catala Sabate M, Nika I (????).
##   _CDMConnector: Connect to an OMOP Common Data Model_. R package
##   version 2.3.0, <https://darwin-eu.github.io/CDMConnector/>.
## 
## A BibTeX entry for LaTeX users is
## 
##   @Manual{,
##     title = {CDMConnector: Connect to an OMOP Common Data Model},
##     author = {Adam Black and Artem Gorbachev and Edward Burn and Marti {Catala Sabate} and Ioanna Nika},
##     note = {R package version 2.3.0},
##     url = {https://darwin-eu.github.io/CDMConnector/},
##   }

License: Apache 2.0

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Install

install.packages('CDMConnector')

Monthly Downloads

10,052

Version

2.3.0

License

Apache License (>= 2)

Issues

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Maintainer

Adam Black

Last Published

January 10th, 2026

Functions in CDMConnector (2.3.0)

listTables

List tables in a schema
%>%

Pipe operator
summariseQuantile2

Quantile calculation using dbplyr
downloadEunomiaData

Download Eunomia data files
dropTable.db_cdm

Drop table from a database backed cdm object
dateadd

Add days or years to a date in a dplyr query
eunomiaIsAvailable

Has the Eunomia dataset been cached?
version

Get the CDM version
tblGroup

CDM table selection helper
eunomiaDir

Create a copy of an example OMOP CDM dataset
requireEunomia

Require eunomia to be available. The function makes sure that you can later create a eunomia database with eunomiaDir().
datepart

Extract the day, month or year of a date in a dplyr pipeline
exampleDatasets

List the available example CDM datasets
generateCohortSet

Generate a cohort set on a cdm object
snapshot

Extract CDM metadata
computeDataHashByTable

Compute a hash for each CDM table
inSchema

Helper for working with compound schemas
generateConceptCohortSet

Create a new generated cohort set from a list of concept sets
computeQuery

Execute dplyr query and save result in remote database
reexports

Objects exported from other packages
readCohortSet

Read a set of cohort definitions into R
asDate

as.Date dbplyr translation wrapper
benchmarkCDMConnector

Run benchmark of tasks using CDMConnector
cdmSample

Subset a cdm object to a random sample of individuals
cdmFlatten

Flatten a cdm into a single observation table
cdmSubset

Subset a cdm object to a set of persons
cdmDisconnect.db_cdm

Disconnect the connection of the cdm object
cdmCon

Get underlying database connection
cdmFromCon

Create a CDM reference object from a database connection
appendPermanent

Run a dplyr query and add the result set to an existing
CDMConnector-package

CDMConnector: Connect to an OMOP Common Data Model
copyCdmTo

Copy a cdm object from one database to another
cdmWriteSchema

Get cdm write schema
datediff

Compute the difference between two days
cdmSubsetCohort

Subset a cdm to the individuals in one or more cohorts
dbms

Get the database management system (dbms) from a cdm_reference or DBI connection
dbSource

Create a source for a cdm in a database.
summariseQuantile

Quantile calculation using dbplyr