Related Experiment Video
Updated: Jun 28, 2026

Measuring Psoriasis Severity at Home
Published on: March 1, 2024
Test-retest reliability of disease activity core set measures and indices in rheumatoid arthritis
1Department of Rheumatology, Diakonhjemmet Hospital, Oslo, Norway. till.uhlig@diakonsyk.no
Aim:
To examine the test-retest reliability of the rheumatoid arthritis (RA) core disease activity measures and derived composite indices.
Methods:
A total of 28 stable patients with RA had 2 complete assessments within 1 week, which included the 7 RA core disease activity measures and derived disease activity indices (28-joint Disease Activity Score (DAS28), Simplified Disease Activity Index (SDAI), Clinical Disease Activity Index (CDAI), RA Disease Activity Index (RADAI) and Routine Assessment of Patient Index Data (RAPID3)). The intraclass correlations (ICC), the smallest detectable difference (SDD) and minimal detectable change as percentage of the maximum score (MDC%) were estimated as measures of test-retest reliability.
Results:
Correlations for the disease activity indices were high. SDDs (MDC%) to detect a true improvement or deterioration with 95% confidence were: DAS28 1.32 (14.4%), SDAI 8.26 (9.6%), CDAI 8.05 (10.6%), RAPID3 1.48 (14.8%) and RADAI 1.49 (14.9%). Thus, SDDs were rather high, and the MDC% values were of a similar magnitude of 10% to 15% for all seven core data set measures.
Conclusions:
SDDs of the DAS28, SDAI and CDAI were close to limits to detect important improvement. Clinicians should be aware of measurement error. Nonetheless, RA core data set measures and indices obtained from a health professional, laboratory and patient self-report had similar reliability.
More Related Videos
04:50Preliminary Study on Acupuncture Combined with Grain-sized Moxibustion for Treating Rheumatoid Arthritis with Finger Joint Pain
Published on: May 16, 2025
08:40Isokinetic Robotic Device to Improve Test-Retest and Inter-Rater Reliability for Stretch Reflex Measurements in Stroke Patients with Spasticity
Published on: June 12, 2019
Related Concept Videos
Rheumatic Heart Disease II: Clinical Manifestations and Diagnostic Studies
Reliability and Validity
Rheumatic Heart Disease I: Introduction
Pericarditis II: Clinical Features and Diagnostic Tests
Atherosclerosis II: Clinical Manifestations and Diagnostic Tests
Rheumatic Heart Disease III: Medical Management