Records / De-identification rules
A person reads records picked at random
Rules read every record; a person reads a random sample of the rewritten ones. With nothing found in n records, the share still holding an identifier is below 1 - 0.05^(1/n) at 95% confidence. A sample needs a short reading; a delivery needs enough records for that bound to fall below 1%. Anything found sends the run back.
Dated 28 Mar 2025Source checked 15 Oct 2026Page out of reach at the last check, 16 Oct 2026Basis: our standard
In the source's own words
“If the upper 95% confidence limit of the estimated risk was larger than the EMA and Health Canada recommended threshold of 0.09, then transformations were performed on the quasi-identifiers until the estimated upper risk limit was at or below 0.09.”
Where it was read
Also read from the same source
- Details that identify together are coarsened and measured
- ICO anonymisation guidance: the same information can be personal data for one party and anonymous for another (Information Commissioner's Office, Anonymisation guidance, 'How do we ensure anonymisation is effective?', 28 March 2025 (under review after the Data (Use and Access) Act))
- ICO anonymisation guidance: the motivated intruder test (Information Commissioner's Office, Anonymisation guidance, 'How do we ensure anonymisation is effective?', 28 March 2025)
- An independent provider tests and certifies before each transfer
- Nothing identifying leaves your computer
- Stand-ins from a secret key you keep, never a plain hash
Figures it counts in
Cited in this guide