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T
Transfer impact assessment (TIA)
T
Trial master file (TMF)
U
UK GDPR
U
Unexpected serious adverse reaction (SUSAR)
V
Validation (computerised system validation, CSV)
V
Vendor assessment (third-party risk management)
V
Vital interests (Art. 6(1)(d) GDPR)
V
Vulnerable participants (vulnerable subjects)
W
Wearables and digital health technologies (DHT)
W
Withdrawal (of consent and from a clinical trial)
W
World Health Organization (WHO)
X
XAI (explainable artificial intelligence)
Y
Yellow Card scheme (UK)
Z
Zero-knowledge proof
Z
Zero trust architecture
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Term of the Day

Natural history study

A natural history study is a preplanned observational study intended to track the course of a disease over time, identifying demographic, genetic, environmental and other variables that correlate with its development and outcomes in the absence of intervention, or under standard of care. Designs may be retrospective (chart review of existing records) or prospective (longitudinal follow-up of a cohort or registry).

Natural history data is particularly important in rare and paediatric diseases, where randomised placebo-controlled trials may be infeasible or unethical. The FDA (guidance on rare disease natural history studies, 2019) and the EMA accept well-designed natural history studies to define endpoints and biomarkers, identify patient subgroups, estimate sample sizes and, in some cases, serve as external or historical control arms for single-arm trials supporting orphan products.

Because they are non-interventional, natural history studies fall outside the CTR and are governed by national law (for example France's MR-003 or MR-004 reference methodologies) and by the GDPR. They typically involve secondary use of medical records, long-term follow-up, genetic data and small populations in which anonymisation is rarely achievable, so pseudonymisation, a DPIA and a robust research legal basis under Art. 9(2)(j) are essential. Registries maintained by patient organisations or academic consortia raise additional questions of joint controllership and data access governance.

E

European Health Data Space (EHDS)

The European Health Data Space (EHDS), Regulation (EU) 2025/327, is the first sector-specific European data space, establishing common rules for the use of electronic health data across the EU. It entered into force on 26 March 2025 and applies from 26 March 2027, with the main obligations phased in: primary-use rules and cross-border exchange through MyHealth@EU for priority categories (patient summaries, e-prescriptions) from 2029, further categories from 2031, and the secondary-use framework from 26 March 2029 for most data categories and 2031 for genomic and other complex data.

For primary use, the EHDS gives patients rights to access, download and share their electronic health records in a European exchange format, requires EHR systems to meet interoperability and security requirements, and lets patients restrict access by health professionals. For secondary use, it obliges "data holders" (hospitals, insurers, registries, pharmaceutical companies for certain data such as trial results) to make defined categories of electronic health data available, through national health data access bodies, to "data users" for permitted purposes including scientific research, innovation, public health, policy and regulatory activities, while prohibiting uses such as insurance pricing, marketing and decisions detrimental to individuals. Access is granted by data permit, data is provided in pseudonymised or anonymised form in secure processing environments, and Member States may allow patients to opt out of secondary use.

The EHDS does not replace the GDPR: it supplies the Union-law basis for Art. 6(1)(e) and Art. 9(2)(g), (h), (i) and (j) processing and harmonises access procedures, but controllership, DPIAs, security and transfer rules continue to apply. For pharmaceutical and MedTech companies it will open real-world data access across borders and, at the same time, create data-holder duties for their own datasets; for HealthTech vendors it sets certification requirements for EHR systems and wellness applications. Preparation involves data inventories, interoperability roadmaps and governance for participation in health data warehouses and access bodies. See iliomad's health data platform services.