RAPID3 or Routine Assessment of Patient Index Data 3  is a disease activity index that is computed from a short and simple questionnaire. It assesses the effect of arthritis on daily life. RAPID3 is designed to be quick and easy to fill by a patient, without requiring the help of a practitioner. Although it is quite simple, this index accurately captures the disease activity and is sensitive to change. It is correlated to DAS28 or CDAI with the additional advantage that it does not require a formal joint count. It was originally designed for patients with rheumatoid arthritis but is also used to address other pathologies such as psoriatic arthritis, osteoarthritis, spondyloarthropathies, lupus, and gout.
Three different dimensions are taken into account:
- physical abilities, through 13 questions,
- pain, through a personal evaluation between 0 and 10,
- health, through a personal evaluation on a 0-10 scale.
The RAPID3 score is computed as follows :
First, the results of the 13 questions are reduced to a score between 0 and 10.
Then, we add the pain and health scores.
RAPID3 scores can be interpreted in terms of 4 categories :
- from 1 to 3 : near remission,
- from 4 to 6 : low severity,
- from 7 to 12 : moderate severity,
- from 13 to 30 : high severity.