SELF-REPORT FUNCTIONAL DISABILITY SCORES AND THE USE OF DEVICES - 2 DISTINCT ASPECTS OF PHYSICAL FUNCTION IN RHEUMATOID-ARTHRITIS

Objectives-Self report scores of physical disability and the use of de vices or assistance in performing activities are sometimes integrated in one index of physical function, although they are aimed at measurin g different dimensions of physical disability. The properties of both parameters were evaluated in two groups of patients with rheumatoid ar thritis (RA). Methods-A group of patients with RA of recent onset was compared with a group with established disease on four parameters of d isability: use of devices, use of personal assistance, and scores on a validated Dutch version of the Health Assessment Questionnaire Disabi lity Index, with and without integrating the use of devices or assista nce. Correlation coefficients among disability parameters were calcula ted. In multiple regression analysis the influence of disease duration on the disability parameters was determined after disease activity, p sychological wellbeing, and demographical characteristics had been con trolled. Results-Functional disability scores were mainly related to i nflammatory activity and psychological wellbeing, whereas the use of d evices had a strong relation with disease duration, independent of cur rent disease activity. Integrating these parameters of disability yiel ded a parameter that was still mainly associated with disease activity . Conclusion-Self report scores of functional disability and the use o f devices represent distinct dimensions of physical function in RA. In tegrating both parameters into one measure of physical disability does not provide an index adequately reflecting both dimensions. The use o f both parameters to measure outcome in long term clinical studies is recommended.