Background - Although many disability questionnaires measure fact very efficiently, they do not allow for consideration of the relevance of that disability to the patient. Data suggest that professionals misinterpret the relevance of disability for the patient and thus, also, the outcome of treatment. Objectives - Firstly, to examine agreement on levels of importance for the items on a validated disability scale (Health Assessment Questionnaire (HAQ) and Modified HAQ (MHAQ)), within groups of patients with rheumatoid arthritis, health professionals, and controls. Secondly, to see if functional items important to patients are included in the HAQ, and whether the HAQ items are important to patients. Methods - 25 patients with RA, 25 rheumatology health professionals, and 25 healthy controls were asked to rate the importance of the HAQ (20 items) and MHAQ (eight domains). Before seeing the HAQ, patients were asked to generate items of function important to them. Results - Only a slight-fair agreement within each group was found for the level of importance of the HAQ and MHAQ, and also within any combination of the groups (κ values <0.38). Most of the functional items valued by patients were contained on the HAQ (70%), and no HAQ items were consistently rated as unimportant. Conclusion - Patients, professionals, and healthy controls do not agree on the importance of disabilities. These data support the need to assess the personal impact of disability, as well as disability itself. Individual importance of disability weighted by level of disability is proposed as a model for calculating the personal impact of disability. A new tool to assess the personal impact of disability is being developed.