Study attributes

It is useful to provide a very broad overall classification of clinical studies as to their type. The classification in the MDR system is taken from ClinicalTrials.gov, and is listed below:

id	name	description	source
11	Interventional	A clinical trial.	ClinicalTrials.gov
12	Observational	Any form of non-interventional research.	ClinicalTrials.gov
13	Observational Patient Registry	Collecting data for a designated registry.	ClinicalTrials.gov
14	Expanded access	Off label usage of a new product for individuals.	ClinicalTrials.gov
15	Funded programme	With a single or linked series of grants.	ClinicalTrials.gov
0	Not yet known	Dummy value supplied by default on entity creation.	ClinicalTrials.gov

For studies it is useful to provide a basic categorisation of their current recruiting status, to give an idea of where the study is within the normal life cycle. This data is often available from trial registry entries.

The options in the NDR system are taken from the largest such registry, ClinicalTrials.gov, (from its overall_status field, which appears to be a combination of the overall recruitment data point and the availability of the relevant data). They are listed below:

id	name	description	source
11	Withdrawn	Study halted prematurely, prior to enrolment of first participant.	ClinicalTrials.gov
12	Available	Recruitment status available on request but no details provided.	ClinicalTrials.gov
13	Withheld	Recruitment status not provided.	ClinicalTrials.gov
14	Recruiting	Participants are currently being recruited, whether or not any participants have yet been enrolled.	ClinicalTrials.gov
15	Active, not recruiting	Study is continuing, meaning participants are receiving an intervention or being examined, but new participants are not currently being recruited or enrolled.	ClinicalTrials.gov
16	Not yet recruiting	Participants are not yet being recruited.	ClinicalTrials.gov
17	No longer available	Recruitment status no longer available.	ClinicalTrials.gov
18	Suspended	Study halted prematurely but potentially will resume.	ClinicalTrials.gov
19	Enrolling by invitation	Participants are being (or will be) selected from a predetermined population.	ClinicalTrials.gov
20	Approved for marketing	The study has concluded and the medical agent that was the focus of the study has been approved for marketing (in the US).	ClinicalTrials.gov
21	Completed	The study has concluded normally; participants are no longer receiving an intervention or being examined (that is, last participant’s last visit has occurred).	ClinicalTrials.gov
22	Terminated	Study halted prematurely and will not resume; participants are no longer being examined or receiving intervention.	ClinicalTrials.gov
0	Unknown status	Status information not provided.	ClinicalTrials.gov