Objective: To estimate relative efficiencies of the 7 rheumatoid arthritis (RA) Core Data Set measures to distinguish adalimumab from control treatments in 4 clinical trials.
Methods: Four adalimumab clinical trials were analyzed for arithmetic and percentage changes for each Core Data Set measure from baseline to endpoint: 3 assessor/physician measures -- swollen joints, tender joints, and global estimate; 1 laboratory test -- C-reactive protein; and 3 patient measures -- physical function, pain, and global estimate. Relative efficiencies of each measure to distinguish adalimumab from control group responses were assessed, with tender joint count as the referent measure.
Results: Relative efficiencies were in a similar range for physician/assessor, patient, and laboratory measures, with some variation between trials. Among physician/assessor measures, relative efficiencies for global estimates were greater than for swollen and tender joint counts in 8/8 comparisons. Among patient measures, relative efficiencies for global estimates were greater than for physical function and pain scores in at least 6/8 comparisons. Among all measures, relative efficiencies for patient global estimates were greater than for swollen joint counts in 5/8 comparisons, and for tender joint counts in 8/8 comparisons.
Conclusion: Patient and physician/assessor measures distinguished adalimumab from control treatment groups in similar ranges. Among all measures, physician/assessor global estimate was most efficient, and tender joint count least efficient, in all 4 trials. This information suggests that while joint counts are the most specific measure to assess RA, their sensitivity to detect treatment effects in patients with RA is generally no greater, and usually less, than other measures.