Table 12.

Potential instances that could lead to inferring patient information

Patient	Type of PI	Year of document	Number of sequential records read to obtain this information	Reason for appearance on CRIS	Confidence in re-identification
2	Patient prison reference number	2012	12	No rule to de-identify prison reference numbers or prison contact information	Low: cannot be verified, and misspellings [22]
	Prison contact phone number			Typographical error in patient’s last name
	Patient last name