Objective: To analyze 2 indices composed of the 3 patient reported outcomes (PRO) in the American College of Rheumatology (ACR) Core Data Set--physical function, pain, and global estimate--without joint count or laboratory data, for capacities to distinguish active from control treatments in 4 pivotal clinical trials.
Methods: Data from 4 clinical trials involving adalimumab, in combination with methotrexate or other disease-modifying antirheumatic drugs (DMARD) or as monotherapy, versus control treatment were made available to analyze properties of various indices. A categorical PRO-Index M was defined as "majority" improvement in 2 of the 3 PRO measures at 20%, 50%, and 70% levels; results were evaluated to analyze agreement with ACR20, ACR50, ACR70 responses and an "all Core Data Set measures" index based on 4 of the 7 measures having such levels of improvement. A continuous PRO-Index C was defined as the median or 2nd highest of 3 percentage differences from baseline to endpoint; results were evaluated to analyze agreement with a continuous ACR-N, "all Core Data Set measures" index, and Disease Activity Score 28 (DAS28).
Results: All indices distinguished active versus control treatment at similar levels, including PRO-Index M versus ACR20, ACR50, and ACR70 responses, and PRO-Index C versus DAS28.
Conclusion: PRO indices based only on patient questionnaire data, without joint counts or laboratory tests, may be useful quantitative measures of therapeutic efficacy for use in standard rheumatology clinical care.