Harmonizing WHO's International Classification of Diseases (ICD) and International Classification of Functioning, Disability and Health (ICF): importance and methods to link disease and functioning

Background: To understand the full burden of a health condition, we need the information on the disease and the information on how that disease impacts the functioning of an individual. The ongoing revision of the International Classification of Diseases (ICD) provides an opportunity to integrate functioning information through the International Classification of Functioning, Disability and Health (ICF). Discussion: Part of the ICD revision process includes adding information from the ICF by way of "functioning properties" to capture the impact of the disease on functioning. The ICD content model was developed to provide the structure of information required for each ICD-11 disease entity and one component of this content model is functioning properties. The activities and participation domains from ICF are to be included as the value set for functioning properties in the ICD revision process. Summary: The joint use of ICD and ICF could create an integrated health information system that would benefit the implementation of a standard language-based electronic health record to better capture and understand disease and functioning in healthcare.