Correlation between objective and subjective measures of hand function in patients with rheumatoid arthritis

The association between the Sollerman test of hand grip and the Sequential Occupational Dexterity Assessment (SODA) and their relationship to impairment and subjective disability measures were examined. Twenty-five patients with rheumatoid arthritis affecting their hands participated in a clinical and subjective evaluation. Clinical evaluation included the use of the two hand function instruments and measurement of finger range of motion. Subjective evaluation was done by means of a patient questionnaire comprising 20 questions from the Health Assessment Questionnaire and by visual analog scales for rating pain severity and hand function. Results confirmed a strong association between the Sollerman test of hand grip and the SODA. Both instruments were found to correlate significantly with subjectively assessed hand function. Associations between the results of the two hand function tests and subjective pain and disability assessments in global daily tasks were weak. The SODA instrument more consistently correlated to the limitations in finger motion than did the Sollerman test of hand grip. This study demonstrates that the SODA and the Sollerman test of hand grip produce similar information under controlled conditions in this patient group despite their differences in conceptual development and measurement properties. A generalized measure such as the Health Assessment Questionnaire or the pain visual analog scale alone is insufficient to represent what patients can do with their hands in daily life.