Description of a VUHID identifier

A VUHID identifier is 32 characters arranged to look like a large number. Figure 1 shows that each identifier consists of four subcomponents but in clinical use the identifier should always be treated as a single entity.

Structure of a typical VUHID identifier

There are up to 16 initial numeric digits that form what is called the prefix. A single period represents the delimiter between the prefix and the subsequent characters. Following the delimiter are eight check digits and then there are seven privacy class digits.

Open and private identifiers

In the case of an open VUHID identifier (OVID) the seven privacy class digits are all zeros. For a private VUHID identifier (PVID) at least one of the privacy class digits is non-zero. Notice that, in order to make the display of identifiers more compact, it is permitted to eliminate the display of any leading zeros in the identifier as well as any trailing privacy digits (but check digits must always be displayed even if they are zero.) As a result, VUHID identifiers may be displayed with varying lengths from 12 digits upwards but the actual stored identifier always is a full 32 digits.

By convention an OVID is printed on a green background and a PVID is printed on a red background but the real difference is that for an OVID the privacy class digits are all zero while for a PVID there is at least one non-zero privacy class digit.

Identifier Cards

Normally as a patient you will see your VUHID identifier printed on some sort of identification card. Figure 2 provides an example of what such a card might look like.

Notice several things about this card. The green background indicates that this is an open identifier. You may use this identifier for any healthcare information that you want to be freely accessible. The VUHID logo indicates that this identifier has been issued by the Voluntary Universal Healthcare Identification system. You can sign this card with your name in the space provided. The actual VUHID identifier is the number given below the patient name. The bar code (and possibly a magnetic stripe on the back of the card) contains a machine-readable form of the identifier to make it easy to process your identifier automatically. The identifier issued to you is unique and permanent. No one else will have one exactly like it and it is designed so that you can use it for the rest of your life. Because it is an open identifier that can be used for many purposes you should only need one open voluntary identifier. You will be able to obtain such an identifier at no cost.

Some aspects of medical information need to be kept private. For those situations you will want to have private voluntary identifiers (PVIDs). PVIDs are in most ways very similar to OVIDs. They can be used to link various pieces of clinical information but with a PVID other people do not know the identity of the person involved. You will request them in a manner similar to OVIDs and they are also provided to you at no cost when you request one from your physician. There are a few significant differences, however. The card on which a PVID is printed will have a red or colored background. You may also notice that there are one or more extra digits in the part of the identifier occurring after the decimal point. Also notice that your name does not appear on the card. Do not put your name on a PVID card. This would put your identity at risk if you lose the card. Instead, put some sort of symbol or squiggle that you will be able to recognize but that other people will not be able to interpret. A PVID works by allowing healthcare organizations to use the identifier for medical information-processing functions without revealing the identity of the person involved. Because of the narrow focus of each PVID it is likely that you will require many PVIDs over time. The VUHID system is designed to provide as many PVIDs as you need.