Masking (Electronic Health Record)


In Electronic Health Records data masking, or controlled access, is the process of concealing patient health data from certain healthcare providers. Patients have the right to request the masking of their personal information, making it inaccessible to any physician, or a particular physician, unless a specific reason is provided. Data masking is also performed by healthcare agencies to restrict the amount of information that can be accessed by external bodies such as researchers, health insurance agencies and unauthorised individuals. It is a method used to protect patients’ sensitive information so that privacy and confidentiality are less of a concern. Techniques used to alter information within a patient’s EHR include data encryption, obfuscation, hashing, exclusion and perturbation.

Confidentiality

The increased access that transpires from introducing EHR's is seen as a large concern to some patients. Masking information is a technique that contributes to establishing the confidentiality of EHR's, as a large amount of sensitive information is contained within these records. History of health outcomes such as drug/alcohol abuse, sexually transmitted infections or abortion during pregnancy are known to lead to social discrimination and cause social harm to the patient, hence the importance of protecting the content within EHR's. Masking limits the access that internal and external individuals can have to a particular record, increasing the protection of its contents. When patients apply for masking of their EHR, health services must meet their needs and alter the system accordingly so that unauthorised individuals can't gain access.

Patient Masking Requests

Unmasking

In patient care authorised user's have the ability to override masking and access restrictions under emergency circumstances. If a patient is in a critical health state and treatment is urgently required, physicians are provided with the right to access all required information within the EHR. This mechanism is known as "breaking the glass". Any unmasking of a patient's EHR is audited and a sufficient reason for access is generally required.

EHR Data Masking Techniques

Masking refers to sets of alterations and changes made to protect information within the confines of Electronic health records. Not only is masking performed at a patients request, it is a common method used to assist in the conduction of clinical and epidemiological research. It reduces confidentiality and privacy concerns associated with supplying information to external bodies. In general, direct identifiers are removed from the dataset, replaced with random values, changed using the hashing function, or restored with a unique key. Mechanisms as such are expanded on under the following headings:

Encryption

Data Obfuscation

Data Perturbation

Data Exclusion

Data Hashing