Skip to content


Switch branches/tags

Latest commit


Git stats


Failed to load latest commit information.
Latest commit message
Commit time

ctcovidstop: Clinical trials that stopped during the Covid-19 pandemic

Last updated on 2022-07-14

This R package provides a database of all NCT Numbers corresponding to clinical trials that were "stopped" (had their overall status changed to "Terminated," "Suspended," or "Withdrawn") after 2019-12-01. This dataset indicates the date that a trial was stopped, whether it was started again and on what date, and the contents of the "why stopped?" field on the date the trial stopped. This dataset also includes columns with manually coded data for whether the "why stopped?" field explicitly indicates that the reason for stopping included the SARS-CoV-2 pandemic.

To install and use

This package is not available on CRAN, and must be installed via Github:


After installation, the package and data set can be loaded as follows:


This package provides a data frame, c19stoppedtrials, which can be loaded via the R package with data(c19stoppedtrials). The same data frame is also provided as a CSV in this repository as inst/extdata/c19stoppedtrials.csv.

c19stoppedtrials contains 8 columns. See below for example rows:

nctid stop_date stop_status restart_date restart_status why_stopped covid19_explicit restart_expected
NCT04007003 2019-12-02 Terminated NA NA Sponsor decision FALSE NA
NCT03693833 2020-03-16 Suspended 2020-06-15 Recruiting COVID-19 TRUE FALSE
NCT04161976 2020-04-20 Suspended 2020-06-03 Recruiting Enrollment on hold due to COVID-19 pandemic. TRUE TRUE

Each row in this data frame contains an NCT Number from (nctid column) and a date on which the corresponding clinical trial record's overall status was first changed to "Terminated", "Suspended" or "Withdrawn" from any other overall status after 2019-12-01 (stop_date column). The status that the trial was changed to on that date is indicated in the stop_status column.

A trial is only included if the study's overall status changed to "Terminated", "Suspended" or "Withdrawn" from any other overall status after 2019-12-01. If a trial's overall status was already "Terminated", "Suspended" or "Withdrawn" prior to 2019-12-01 and it never became active and then stopped after 2019-12-01, it would not be included, even if the "why stopped?" field was updated to include a reference to Covid-19 (e.g. NCT03365921).

If the trial started again (overall status changed from "Terminated", "Suspended" or "Withdrawn" to any other overall status) after being "stopped" according to the definition above by the date that this data set was last updated, the date that the trial restarted is recorded under restart_date; otherwise this column contains NA. The status that the stopped trial was changed to is indicated in the restart_status column.

The reason that the trial was stopped, as reported on the first stopped historical version of the clinical trial registry entry on, is recorded in the why_stopped field. If no reason is given, this column contains NA.

If why_stopped cites Covid-19 explicitly as a reason why the trial was stopped, the covid19_explicit column is TRUE, otherwise FALSE. In the case that there is no value for why_stopped, covid19_explicit is FALSE. This data point was manually rated by BGC.

Trials that cite waning levels of Covid-19 infections, etc. as their rationale for stopping were not considered to be stopped because of Covid-19, and so covid19_explicit would be FALSE (e.g. NCT04390191).

The stop_date, stop_status and why_stopped will reflect only the first time the trial was stopped after 2019-12-01. In cases where a trial stops after 2019-12-01 without citing Covid-19 in the why_stopped field, starts again, and then stops a second time, citing Covid-19 as a reason why the study stopped (e.g. NCT03728504), the trial's covid19_explicit column is FALSE.

In cases where a trial was stopped with no rationale reported in the version of the trial history where it was stopped, and then in a later version, the why_stopped field was updated to include a rationale, the updated rationale for stopping would not be included in this data set.

If covid19_explicit is FALSE, restart_expected is NA. If covid19_explicit is TRUE, and there is also a stated expectation that the trial will start again in why_stopped, restart_expected is TRUE, otherwise FALSE. Trials that mention the study is "on hold" or "expected to resume" or that the stop was "temporary", etc. were included. This data point was manually rated by BGC.

Citing ctcovidstop

These data are provided under a Creative Commons by-attribution licence.

Here is a BibTeX entry for ctcovidstop:

  Title          = {ctcovidstop},
  Author         = {Carlisle, Benjamin Gregory},
  Organization   = {The Grey Literature},
  Address        = {Berlin, Germany},
  url            = {},
  year           = 2022

If you use this data set and you found it useful, I would take it as a kindness if you cited it.


Benjamin Gregory Carlisle PhD


No description, website, or topics provided.