The Impact of Data Suppression on Re-Identification Risk and Data Access in the National Child Abuse and Neglect Data System.

In summer 2024, the Children's Bureau revised the rules that govern data suppression in datasets from the National Child Abuse and Neglect Data System (NCANDS). To minimize the risk of re-identification, researchers had previously been unable to identify counties with fewer than 1000 annual maltreatment cases. Under the new data suppression rule, county identifiers will only be suppressed for counties with fewer than 700 cases. In this report, we document the consequences of this shift for research data access and re-identification risks, showing that reducing the data suppression threshold increased the number of identifiable counties from 835 to 1096 (a 31.3% increase) and doubled the number of identifiable rural counties. The percentage of reported children who face a particularly elevated re-identification risk due to having unique demographic characteristics increased from 0.7% to 1.0%.