An Index of Patient Reported Outcomes (PRO-Index) Discriminates Effectively Between Active and Control Treatment in 4 Clinical Trials of Adalimumab in Rheumatoid Arthritis
THEODORE PINCUS, CECILIA CHUNG, OSCAR G. SEGURADO, INGRID AMARA, and GARY G. KOCH
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. (First Release Oct 15 2006; J Rheumatol 2006;33:2146-52)
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From the Vanderbilt University Medical Center, Nashville, TN; Abbott Laboratories, Abbott Park, IL; Quintiles, Inc., Durham, NC; and the University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
T. Pincus, MD, Professor of Medicine; C. Chung, MD, PhD, Vanderbilt University Medical Center; O.G. Segurado, MD, PhD, Abbott Laboratories; I. Amara, DrPH, Quintiles, Inc.; G.G. Koch, PhD, University of North Carolina at Chapel Hill.
Address reprint requests to Dr. T. Pincus, Division of Rheumatology and Immunology, Vanderbilt University School of Medicine, 203 Oxford House, Box 5, Nashville, TN 37232-4500. E-mail:email@example.com
Accepted for publication June 6, 2006.