Topic codes are classified by several health areas, e.g. health status (HIS) and cardiovascular function (HES), which include more specific health topics. Each question or measurement included in the database is labelled with at least one topic code according to the health topic code list. Topic codes enable to search surveys that have used a question or a measurement covering a specific health area and topic.

A definition of each HIS and HES topic code has been developed. The definitions need to be updated regularly in the future, to keep up with the technological development in the field of HIS and HES surveys. Complete topic code lists with definitions are available in the database.