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Forty-one coded radiographic films from 16 patients with rheumatoid arthritis were read by 13 observers, using 4 different methods for scoring abnormalities. Although absolute scores differed widely among individual observers, correlation coefficients were greater than 0.850 for approximately 2 of 3 comparisons. When films were ranked, using the median rank of all readers, 72% of individual ranks were within 10% of the median ranks. Among serial films on individual patients, 92% of comparisons between early and late films were interpreted as demonstrating progression of abnormalities when mean standardized scores showed an increase in scores of 15 units or greater. Films with lesser changes were interpreted inconsistently. This study shows good general agreement among readers in scoring radiologic abnormalities of hands and wrists, when applied to a film set showing a broad spectrum of severity, and defines the sensitivity of radiologic detection of disease progression.

Numerous methods for reading abnormalities of rheumatoid arthritis in hand and wrist radiographs have been proposed over the past several decades. There are many differences among these methods, one of the more striking of which is the variation in the number of joints that are scored. In this study, we tested the number of joints that need to be read in order to represent abnormalities accurately and reproducibly, using the scores of multiple observers. Thirteen rheumatologists and radiologists each read a set of 41 hand and wrist films from patients with rheumatoid arthritis. Ten of 13 readers scored 27 joints in each hand and wrist; the other 3 readers scored fewer areas. Fourteen combinations of joints were selected based on the frequency of involvement and the technical adequacy of routine films in assessing a given area. After testing these 14 different combinations, 1 scheme, which included 17 areas read for erosions and 18 areas read for joint space narrowing, was tested further. The correlation coefficients for 10 intraobserver scores derived from this modified scheme compared with the original scores were between 0.981 and 0.997. Seventy-one of 78 interobserver comparisons were better using the new scheme than using the original scheme. These data indicate that the simplified scheme, using a combination of 17 joints to score erosions and 18 to score joint space narrowing, more accurately reflects the extent of abnormalities perceived by a panel of experts than does the original scheme. This abbreviated number of joints shortens the amount of time required to read a set of films and simplifies the scoring of films, since a number of areas that are difficult to read are eliminated from radiographic assessment.

Radiologic assessment of progressive joint destruction in rheumatoid arthritis is generally considered to be the ultimate standard for evaluation of treatment. We compared alternative radiologic techniques by performing a randomized, controlled trial in which hand films of rheumatoid arthritis patients were read by several skilled observes. The number of joints evaluated (34 versus 18) was found to make relatively little difference, but the number of readers and their experience level was critical. Films should be read in pairs. Joint space narrowing and erosion scores were shown to contribute independent information. Use of recommended techniques can reduce the number of patients required and, thus, can reduce the cost of a clinical trial by more than half and can substantially increase the sensitivity and efficiency of a trial. Therefore, critical selection of the method of assessing study endpoint is of great importance.