Install R package ctrdata

In ctrdata: Retrieve and Analyze Clinical Trials Data from Public Registers

knitr::opts_chunk$set(eval = FALSE)

Install package ctrdata on an R system

The R Project website (https://www.r-project.org/) provides installers for the R system. It can be used with software products and graphical user interfaces such as R Studio or from Visual Studio Code.

General information on the ctrdata package is available here: https://rfhb.github.io/ctrdata/.

In R, execute:

install.packages("ctrdata")

For using the development version of package ctrdata, install from GitHub:

# install package under development
install.packages(c("remotes"))
remotes::install_github("rfhb/ctrdata", dependencies = TRUE, build_vignettes = TRUE)

Either of the above should install package ctrdata into the user's library.

Databases to use

At this time, a SQLite, DuckDB, PostgreSQL, MariaDB (local or remote) or MongoDB (local or remote) database can be used with the package ctrdata. A full SQLite database adapter is provided in the R package RSQLite. Suggested installation instructions for PostgreSQL are here and for a local MongoDB server are here; a remote MongoDB database server is accessible here. See here for a speed comparison of the databases; recommended: DuckDB, SQLite or MongoDB local server.

Purpose | Function call -------------------- | -------------------- Create SQLite database connection | dbc <- nodbi::src_sqlite(dbname = "name_of_my_database", collection = "name_of_my_collection") Create DuckDB database connection* | dbc <- nodbi::src_duckdb(dbname = "name_of_my_database", collection = "name_of_my_collection") Create MongoDB database connection | dbc <- nodbi::src_mongo(db = "name_of_my_database", collection = "name_of_my_collection") Create PostgreSQL database connection | dbc <- nodbi::src_postgres(dbname = "name_of_my_database"); dbc[["collection"]] <- "name_of_my_collection" Create MariaDB database connection | dbc <- nodbi::src_mariadb(db = "name_of_my_database", collection = "name_of_my_collection") Use connection with ctrdata functions | ctrdata::{ctrLoadQueryIntoDb, dbQueryHistory, dbFindIdsUniqueTrials, dbFindFields, dbGetFieldsIntoDf}(con = dbc, ...)

• For DuckDB, the JSON extension is needed which can be permanently downloaded as follows:

# user to specify their directory of choice;
# remember to set option for each new R session
options(duckdb.home = "~/.duckdb")

# load and install in above-mentioned 
# directory; only once to be executed
DBI::dbExecute(duckdb::dbConnect(duckdb::duckdb()), 'INSTALL json;')

Attach package ctrdata

After completing the installation, attach the package from the user's library:

library(ctrdata)

Credit to clinical trial registers

Remember to respect the registers' terms and conditions (see ctrOpenSearchPagesInBrowser(copyright = TRUE)).

Quote or reference ctrdata

In any publication, please cite this package as follows:

cat(rev(format(citation("ctrdata"), style = "text")), sep = " or <br/>")

ctrdata documentation built on Aug. 28, 2026, 5:07 p.m.