Validation of the International Classification of Functioning, Disability and Health (ICF) Core Set for rheumatoid arthritis from the patient perspective using focus groups

Functioning is recognized as an important study outcome in
rheumatoid arthritis ( RA). The Comprehensive ICF Core Set for RA
is an application of the International Classification of
Functioning, Disability and Health ( ICF) of the World Health
Organisation with the purpose of representing the typical spectrum
of functioning of patients with RA. To strengthen the patient
perspective, persons with RA were explicitly involved in the
validation of the Comprehensive ICF Core Set for RA using
qualitative methodology. The objective of the study was twofold: to
come forward with a proposal for the most appropriate methodology
to validate Comprehensive ICF Core Sets from the patient
perspective; and to add evidence to the validation of the
Comprehensive ICF Core Set for RA from the perspective of patients.
The specific aims were to explore the aspects of functioning and
health important to patients with RA using two different focus
group approaches ( open approach and ICF-based approach) and to
examine to what extent these aspects are represented by the current
version of the Comprehensive ICF Core Set for RA. The sampling of
patients followed the maximum variation strategy. Sample size was
determined by saturation. The focus groups were digitally recorded
and transcribed verbatim. The meaning condensation procedure was
used for the data analysis. After qualitative data analysis, the
resulting concepts were linked to ICF categories according to
established linking rules. Forty-nine patients participated in ten
focus groups ( five in each approach). Of the 76 ICF categories
contained in the Comprehensive ICF Core Set for RA, 65 were
reported by the patients based on the open approach and 71 based on
the ICF-based approach. Sixty-six additional categories ( open
approach, 41; ICF-based approach, 57) that are not covered in the
Comprehensive ICF Core Set for RA were raised. The existing version
of the Comprehensive ICF Core Set for RA could be confirmed almost
entirely by the two different focus group approaches applied. Focus
groups are a highly useful qualitative method to validate the
Comprehensive ICF Core Set for RA from the patient perspective. The
ICF-based approach seems to be the most appropriate technique.