Information technology concerning SDAI and CDAI.

Disease activity assessment of rheumatoid arthritis has never been trivial. Composite indices like the Disease Activity Score using 28 joint counts 28 (DAS28) and the Clinical Disease Activity Index (CDAI) and the Simplified Disease Activity Index (SDAI) attempted to integrate several core set variables into one readout, which eventually laid the grounds for implementation strategies that targeted disease activity levels, like remission. While CDAI and SDAI were clearly simpler at times when a calculator was needed, this has likely become less relevant in the era of digital records, where core set variables are entered into a computed device after measurement. However, DAS28 has faced new challenges, which are derived from its lack of specificity when it comes to assessing remission. Digital technology has advanced the management of patients with RA in clinical practice, since the disease activity levels can now be followed for each patient over adjustable time periods interesting for the clinician, such as since start of the last treatment. Also for research purposes, the digital records have allowed a more rapid course of projects from the scientific hypothesis to publication, simply by allowing to go to the digital database and select the items and observation needed. This has made clinical research much more efficient. In the digital era, the CDAI and SDAI can still be used on a piece of paper without the necessity of any electronic device, and it is exactly this flexibility and versatility of these two scores that account for their continued success.