subjektid

Subjektid is a term used in Estonian and in data management to refer to the individuals who are the subjects of a study, or to the codes assigned to those individuals for identification. In research contexts, subjektid are participants or study subjects, and the term is often encountered alongside English equivalents such as subject IDs or participant IDs. The concept denotes a means to reference people in data without using names.

Subject identifiers serve to link data about the same individual across time and different data sources. They enable longitudinal analyses, data linkage between surveys, clinical records, and biobanking, and support secure data sharing by keeping identifying information separate from the research data. Well-managed IDs allow researchers to maintain a stable reference to a person’s data while reducing immediate exposure of personal details.

Privacy, governance, and ethics are central to the use of subjektid. Identifiers are typically stored separately from names and other direct identifiers. Re-identification risk arises if an ID is combined with rich quasi-identifying data. Practices such as pseudonymization, data minimization, access controls, and audit trails help mitigate risk. Compliance with applicable privacy laws, such as the GDPR in the European Union, ethics approvals, and informed consent define permissible uses and sharing arrangements.

Formats and documentation vary by study. IDs may be numeric or alphanumeric and can be designed to reflect cohorts or sites. Data dictionaries and crosswalks document the meaning of codes and how they map to other identifiers. Consistent conventions facilitate data integration across studies, while careful governance minimizes privacy risks and supports responsible data reuse.