Specifies whether the individual is currently participating or has previously participated in an interventional clinical trial. In this context, ‘participated’ means the individual has passed the screening period and has been either randomised (in randomised trial) or dosed (in non-randomised trial). If an individual fails the screening period, or is not randomised/dosed for some other reason (for example consent withdrawal, family relocation), this is not classed as participation.

“Interventional” means that the individual has, as part of the trial, received a treatment they would otherwise have not received. If the individual has received a disease-modifying therapy after its marketing authorisation, this use should be reported in the dataset items related to DMTs and must not additionally be reported as an interventional clinical trial, even if further data on the individual's treatment usage is or has been collected as part of a study.

Specifies whether the individual is currently part of another registry and/or natural history study, in addition to this registry.

A patient registry can be defined as “an organized system that uses observational study methods to collect uniform data (clinical and other) to evaluate specified outcomes for a population defined by a particular disease, condition, or exposure, and that serves one or more predetermined scientific, clinical, or policy purposes.” (Gliklich et al. 2014)

Natural history studies can be defined as “epidemiological studies that focus on describing the frequency, features, and evolution of a disease by collecting real-world data from groups of patients suffering from this disease.” (Bevan et al. 2019)

Comma-separated list of the full name of each registry or natural history study in which the individual is currently participating.

For observational studies listed on ClinicalTrials.gov, the NCT number (ClinicalTrials.gov identifier) may be provided instead of the name.