HL7--more than a communications standard.

Health Level Seven (HL7) has evolved from a small, ad-hoc standards developer organisation focused on creating a standard for the interchange of data primarily in the hospital setting to an accredited American National Standard Organisation with wide-spread international participation. The scope of HL7 has expanded to include standards for the interchange of clinical data in all settings, a reference information model, data types, decision support and clinical guidelines, clinical documents and clinical templates, clinical context objects, terminology, security, XML, and the electronic health record. HL7 has become a gathering place for a number of application-oriented groups making use of the organisational freedom of HL7, the gathering of domain experts, and the use of common and sharable solutions to provide health data standards for a variety of purposes. This paper discusses the factors that lead to these diverse activities.