The Foundation Component and the Tabular Lists
The Foundation Component is a multidimensional collection of all ICD entities.
Entities can be diseases, disorders, injuries, external causes, signs and symptoms. Some entities may be very broad, while other are more detailed (e.g. 'injuries to the head' and 'Superficial injury of nose').
The Foundation Component contains also the necessary information to use the entities to build a tabular list - a mono hierarchy in the style of a traditional statistical classification, information on where and how an entity is represented in a tabular list, whether it becomes a grouping, a category with a stem code, or whether it is mentioned as an inclusion in a particular category.
Different tabular lists can be built from the Foundation Component: a set of the so-called congruent tabular lists can be built on the same hierarchical tree. Later, data collected with any tabular list of such congruent lists can always be aggregated to the smallest common denominator, provided that the same rules for reporting, coding, and selection were applied.
In a tabular list, entities of the foundation become categories. The categories are mutually exclusive and jointly exhaustive, and linked to a mono hierarchical tree, i.e. they have only one parent. The information referring to an entity that has become a category and has multiple parents is still available from the foundation.
The core tabular lists for international use are:
- Mortality and Morbidity Statistics (MMS)
- Primary care low resources settings (PCL)
- Primary care intermediate resources setting (PCM)
- Verbal Autopsy (VA)
- Simple Mortality List (SMoL)