Objective: Hand and upper limb involvement is common in rheumatoid arthritis (RA) patients. However, its impact on daily life manual activities has not been fully evaluated. A measure of manual ability was developed, through the Rasch measurement model, by adapting and validating the ABILHAND questionnaire that measures patient's perceived difficulty in performing everyday manual activities.
Methods: One hundred and twelve RA patients were evaluated. The following tests were performed: the ABILHAND questionnaire, the HAQ, the Jamar grip and key pinch strength tests, the Box and Block and the Purdue pegboard dexterity tests. Thirty-five patients were re- assessed to determine the test-retest reliability of ABILHAND and six patients were studied before and after therapy with TNF blockers in order to address sensitivity to change.
Results: The Rasch-refinement of ABILHAND led to a selection of 27 items rated on a 3-level scale. The resulting ability scale was targeted to the ability of the patients. The item-difficulty hierarchy was stable across demographic and clinical subgroups and over time. Grip and key pinch strength and manual and digital dexterity on both hands were significantly, though moderately, correlated with the ABILHAND measures. Manual ability was also significantly related to the number of impaired hands, disease duration, tender and swollen joint counts on upper limbs, disease activity and the HAQ. Sensitivity to change was demonstrated in patients treated with TNF blockers, commensurate with their clinical improvement.
Conclusion. The ABILHAND questionnaire is a clinically valid person-centred measure of manual ability that could be useful in longitudinal RA studies.
- functional status
- outcome measures
- rheumatoid arthritis