Rheumatoid Arthritis: Amara I

Chung CP, Thompson JL, Koch GG, Amara I, Strand V, Pincus T. · Division of Rheumatology and Immunology, Department of Medicine, Vanderbilt University Medical Center, Vanderbilt University, Nashville, Tennessee 37232-4500, USA. · Ann Rheum Dis. · Pubmed #16504992 No free full text.

Abstract: OBJECTIVE: To carry out a meta-analysis designed to compare the discriminant capacities of American College of Rheumatology 50% (ACR50) with 20% (ACR20) responses in clinical trials on rheumatoid arthritis reported after 1997 and to analyse whether ACR50 can be as informative as ACR20 in distinguishing active from control treatments in more recent trials. METHODS: Clinical trials on rheumatoid arthritis reported since 1997 were identified, which included aggressive combinations of disease-modifying antirheumatic drugs and glucocorticoids, as well as powerful new agents-leflunomide, etanercept, infliximab, anakinra, adalimumab, abatacept, tacrolimus and rituximab. A meta-analysis of ACR20 compared with ACR50 responses for 21 clinical trials was carried out on differences in proportions of responders for active and control treatments and corresponding odds ratios (ORs). RESULTS: In all but one clinical trial on rheumatoid arthritis published since 1997 with data available on ACR20 and ACR50, more than 50% of patients who were ACR20 responders among those randomised to active treatment were also ACR50 responders. This phenomenon was seen for control groups in 38% of trials, many of which included treatment with methotrexate. A meta-analysis of the clinical trials indicated a slight advantage to ACR50 for quantifying treatment comparisons, not significant for differences in proportions but significant for ORs. CONCLUSION: ACR20 and ACR50 seem to be similar in distinguishing active from control treatments in clinical trials on rheumatoid arthritis reported since 1997. As ACR50 represents a considerably stronger clinical response, ACR50 may be a preferred end point for contemporary clinical trials on rheumatoid arthritis.

Pincus T, Strand V, Koch G, Amara I, Crawford B, Wolfe F, Cohen S, Felson D. · Division of Rheumatology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA. · Arthritis Rheum. · Pubmed #12632413 links to  free full text

Abstract: OBJECTIVE: To evaluate the capacity of a pooled index of only the 3 patient self-report questionnaire measures among the 7 American College of Rheumatology (ACR) core data set (Core Data Set) measures to distinguish efficacy of active treatment of rheumatoid arthritis (RA) with leflunomide or methotrexate versus placebo in a randomized, controlled clinical trial, and to compare the results with those obtained using the ACR 20% response criteria (ACR20), Disease Activity Score (DAS), and other pooled indices. METHODS: The 7 ACR Core Data Set measures of 1) joint swelling, 2) joint tenderness, 3) physician global assessment, 4) erythrocyte sedimentation rate (ESR), 5) functional disability, 6) pain, and 7) patient global assessment were combined into the following 5 pooled indices: "All Core Data Set" (all 7 measures), "Assessor Only" (measures 1-3), "Assessor + ESR" (measures 1-4), "Patient Only" (measures 5-7), and "Patient + ESR" (measures 4-7). The capacity of each of these 5 indices to detect differences between active treatment and placebo treatment was compared with that of the ACR20 and the DAS using 4 different analytic methods, each of which presented advantages and limitations. Agreement of the indices with one another and with the ACR20 and the DAS was analyzed according to pairwise kappa statistics and Z scores in multivariate logistic regression models. RESULTS: Each of the 5 indices, including "Patient Only," had a similar capacity to detect greater efficacy of leflunomide and methotrexate versus placebo in this clinical trial, according to each of 4 methods, at similar levels of statistical and clinical significance. CONCLUSION: A pooled index of patient self-report questionnaire Core Data Set measures appears to be as informative as ACR20 responses, DAS scores, and pooled indices of all and assessor-derived Core Data Set measures for distinguishing between active treatment and placebo treatment in this RA clinical trial.

Pincus T, Amara I, Segurado OG, Bergman M, Koch GG. · New York University Hospital for Joint Diseases, New York, New York 10003, USA. · J Rheumatol. · Pubmed #18050378 No free full text.

Abstract: 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.

Pincus T, Chung C, Segurado OG, Amara I, Koch GG. · Vanderbilt University Medical Center, 203 Oxford House, Nashville, TN 37232, USA. · J Rheumatol. · Pubmed #17080518 No free full text.

Abstract: 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.

Pincus T, Amara I, Koch GG. · Division of Rheumatology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-4500, USA. · Arthritis Rheum. · Pubmed #15818698 links to  free full text

Abstract: OBJECTIVE: To describe indices that are continuous counterparts of categorical responses to the American College of Rheumatology 20% improvement criteria (ACR20), ACR50, and ACR70, which extend rheumatoid arthritis (RA) clinical trial results and recognize clinical worsening (as well as improvement) with active and placebo treatments. METHODS: Data from a clinical trial of leflunomide, methotrexate, and placebo treatment over 1 year were reanalyzed. Percent change was computed for each of the 7 components of the ACR core set of outcome measures. Four continuous indices were computed: 1) ACR-N (lowest of 3 values: number of swollen joints, number of tender joints, and median of the other 5 measures); 2) composite (median of all 7 measures [3 patient and 3 assessor measures plus erythrocyte sedimentation rate]); 3) patient-only (median of physical function, pain, and global status); and 4) assessor-only (median of number of swollen joints, number of tender joints, and global status). Means, medians, categorical 20%, 50%, and 70% responses, and continuous probability plots were computed according to each index for the 3 treatment groups and were compared with one another and with standard ACR20, ACR50, and ACR70 responses. RESULTS: Mean levels of improvement calculated using the different methods, in patients taking leflunomide, placebo, and methotrexate, respectively, were as follows: ACR-N 20%, -12%, and 13%; composite 43%, 9%, and 33%; patient-only 36%, 0%, and 26%; assessor-only 50%, 20%, and 44%; and ACR20 52%, 26%, and 46%. Differences between leflunomide and placebo were 30-36%, and differences between methotrexate and placebo were 24-26%. CONCLUSION: Continuous indices may be an informative addition to categorical ACR 20%, 50%, or 70% responses to compare efficacies of various treatments in RA, and to describe lower responses to placebo by recognizing worsening as well as improvement.