The International Classification of Functioning, Disability, and Health could be used to measure functioning.
OBJECTIVE
To explore whether it is possible to construct clinical measures of functioning by integrating information obtained across the categories of the International Classification of Functioning, Disability, and Health (ICF) using the ICF Core Set of osteoarthritis (OA) as a case in point.


METHODS
Psychometric study using data from 437 patients with OA from Germany, Italy, Hungary, Serbia, and Singapore. The analyses were performed with the ICF categories of the comprehensive ICF Core Set for OA addressing functioning and using the Rasch model for ordered response options.


RESULTS
A clinical measure with 74 country-specific and seven common ICF categories was created with the pooled data of all countries but Hungary. The overall fit statistic according to the chi(2) was chi(df=405)(2)=451.73, P=0.054, and the Z-fit statistic was Z(mean)=-0.041 (Z(standard deviation [SD])=1.01) for items and Z(mean)=-0.15 (Z(SD)=1.19) for persons. The Person Separation Index r(beta) was 0.92.


CONCLUSIONS
For the first time, a cross-cultural clinical measure of functioning was constructed which integrates ICF categories. The results of this investigation are promising and can contribute to the acceptance and usefulness of the ICF in clinical practice.
Cieza
Alarcos
A
ICF Research Branch, WHO Collaborating Center for the Family of International Classifications, German Institute of Medical Documentation and Information, IHRS, Ludwig-Maximilian University, Munich, Germany.
Hilfiker
Roger
R
Chatterji
Somnath
S
Kostanjsek
Nenad
N
Ustün
Bedirhan T
BT
Stucki
Gerold
G
D000203:Activities of Daily Living; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D003431:Cross-Cultural Comparison; D003430:Cross-Sectional Studies; D004185:Disability Evaluation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000503:physiopathology* / Q000534:rehabilitation; D017063:Outcome Assessment, Health Care / Q000379:methods; D011594:Psychometrics; D016059:Range of Motion, Articular; D012720:Severity of Illness Index