Proposing a method of regional assessment and a novel outcome measure in rheumatoid arthritis

Abstract

We proposed a method of regional assessment in patients with rheumatoid arthritis. The utility of this method was demonstrated by assessing drug efficacy in patients who received infliximab (n = 31) or tocilizumab (n = 6). Joints were divided into four regions: upper/large, upper/small, lower/large, and lower/small. The total joint index was calculated as follows: the sum of tender and swollen joint counts divided by the number of evaluable joints in each region. At the baseline, the total joint index of the upper/small region was the lowest and that of the lower/large region was the highest compared with other regions. The change in the total joint index from the baseline to the 30-week point (Δ) did not differ among the four regions. There were significant close relations of Δ between the upper/small and the upper/large region and between the lower/small and the lower/large region. This method allows us to focus on a specific region and to compare and contrast among them.