The responsiveness of generic health status measures as assessed in patients with rheumatoid arthritis receiving infliximab.
OBJECTIVE
We used a variety of health status measures in 2 groups of patients with rheumatoid arthritis (RA) to assess both the smallest distinguishable difference and the relative responsiveness to change of these measures, when used in clinical practice.


METHODS
Two groups of patients were studied. Group 1: 24 patients with stable RA tested on 2 occasions; Group 2: 60 patients receiving methotrexate tested before and 14 weeks after treatment with infliximab. Assessments were made with self-completed questionnaires: the modified Health Assessment Questionnaire, Medical Outcomes Study Short Form-36 [SF-36 (SF-6D)], EuroQol, and, in some, the standard gamble. Group 2 also had joint counts, and measures of erythrocyte sedimentation rate, C-reactive protein, and hemoglobin.


RESULTS
The limits-of-agreement (Bland-Altman) approach had greater confidence intervals (CI) than did CI based on +/- 2 standard errors of the measurement. Improvement with infliximab could be determined with all measures, however, but the standard gamble seemed least responsive to change.


CONCLUSIONS
The various measures had different degrees of responsiveness, but with all it was possible to show improvement in Group 2 compared to Group 1. There was a closer association of the patient centered measures of improvement with changes in pain score than with joint counts.
Russell
Anthony S
AS
Rheumatic Disease Unit, University of Alberta, Edmonton, Alberta Canada.
Conner-Spady
Barbara
B
Mintz
Alisa
A
Maksymowych
Walter P
WP
D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D018501:Antirheumatic Agents / Q000627:therapeutic use*; D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000523:psychology*; D006305:Health Status Indicators; D006801:Humans; D000069285:Infliximab; D008727:Methotrexate / Q000627:therapeutic use; D011788:Quality of Life; D015203:Reproducibility of Results; D011795:Surveys and Questionnaires / Q000592:standards
D000911:Antibodies, Monoclonal; D018501:Antirheumatic Agents; D000069285:Infliximab; D008727:Methotrexate