How many joints in the hands and wrists should be included in a score of radiologic abnormalities used to assess rheumatoid arthritis.
код для вставкиСкачать1326 HOW MANY JOINTS IN THE HANDS AND WRISTS SHOULD BE INCLUDED IN A SCORE OF RADIOLOGIC ABNORMALITIES USED TO ASSESS RHEUMATOID ARTHRITIS? JOHN T. SHARP, DONALD Y. YOUNG, GILBERT B. BLUHM, ANDREW BROOK, ANNE C. BROWER, MARY CORBETT, JOHN L. DECKER, HARRY K. GENANT, J. PHILIP GOFTON, NEAL GOODMAN, ARVI LARSEN, MARTIN D. LIDSKY, PEKKA PUSSILA, AARON S. WEINSTEIN, and BARBARA N. WEISSMAN 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 Presented at a workshop sponsored by the Joe and Betty Alpert Arthritis Center, Rose Medical Center, Denver, CO, November 28-29, 1983. Supported by a grant from the Eli LiHy Company, Indianapolis, IN. John T. Sharp, MD: Director, Joe and Betty Alpert Arthritis Center, Rose Medical Center, Denver, CO; Donald Y. Young, PhD: Statistician, ARAMIS Data Bank Network, Stanford University, Palo Alto, CA: Gilbert B. Bluhm, MD: Coordinator, Clinical Investigation, Rheumatology Research, Henry Ford Hospital, Detroit, MI; Andrew Brook, MB: Rheumatologist, Yarralumla, Australia: Anne C. Brower, MD: Department of Radiology, George Washington University Medical Center, Washington, DC: Mary Corbett, MB: Consultant Rheumatologist, Middlesex Hospital, London, England: John L. Decker, MD: Director, Clinical Center, NIH, Bethesda, MD; Harry K. Genant, MD: Radiologist, Department of Radiology, University of California Medical Center, San Francisco, CA; J. Philip Gofton, MD: Rheumatologist, University of British Columbia, Vancouver, BC: Neal Goodman. MD: Radiologist, Department of Radiology, St. Anthony Hospital, Denver, CO: Arvi Larsen, MD: Spenshults Reumatikersjukhus, Oskarstrom, Sweden: Martin D. Lidsky, MD: Chief, Rheumatology Section, VA Medical Center, Houston, TX; Pekka Pussila, MD: Radiologist, Department of Radiology, Reumasaation Sairaala, Heinola, Finland; Aaron S. Weinstein, MD: Department of Radiology, University of Cincinnati Medical Center, Cincinnati, OH: Barbara N. Weissman, MD: Radiologist. Department of Radiology, Brigham and Women’s Hospital, Boston. MA. Address reprint requests to John T. Sharp, MD, Alpert Arthritis Center, 4567 East Ninth Avenue, Denver, CO 80220. Submitted for publication November 13, 1984; accepted in revised form May 6, 1985. Arthritis and Rheumatism, Vol. 28, No. 12 (Decemher 1985) hand and wrist films from patients with rheumatoid arthritis. Ten of 13readers 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. Destruction of bone and cartilage is a regular consequence of persistent, active synovitis in patients with rheumatoid arthritis (RA). Because finger and wrist joints are frequently involved in this disease, a number of investigators over the past several decades have proposed that an assessment of the severity of erosions and cartilage loss in hand and wrist joints, logically, would represent an index of the outcome of this disease process (1-6). More recently, it has been proposed that individual joints should be scored separately and the scores summed in order to accurately SCORING JOINT ABNORMALITIES IN RA represent the degree of changes in the hands and wrists (7-10). In November 1983, a group of radiologists and rheumatologists collaborated in testing several different methods of measuring the radiologic changes in these joints. There was generally good agreement among experienced observers, even when using different methods (11). However, that study did not resolve 2 important questions: 1) Does any single method of scoring abnormalities of individual joints give results that are more reproducible than other methods do? and 2) Which joints in the hands and wrists should be scored? This report addresses the latter question. In determining which joints and how many joints should be included in the score, we considered: the frequency of involvement of individual joints, the time course of development of lesions in individual joints with greater disease duration, the technical factors which determine ease of reading definitive lesions of a given joint or area, and the number of joints required to sample adequately the abnormalities found in a population of patients having a broad spectrum of disease severity. Frequency analysis was done on radiographic data in the Alpert Arthritis Center American Rheumatism Association Medical Information System (ARAMIS) data bank (12) to assess the contribution of a given joint to the total radiologic score. Differences in thle frequency of joint involvement, as perceived by different observers, were determined using the scores of 13 observers who read the same set of study films in the project mentioned above (1 1). However, the films in this study set were not randomly chosen, but were selected in order t o represent a broad spectrum of involvement, ranging from those films that were considered as demonstrating no diseases to those films demonstrating very severe disease. Therefore, the frequency data presented were based on analysis of the film records in the Alpert Arthritis Center ARAMIS data bank. Cluster analysis was performed on the erosion and joint space narrowing (JSN) scores, using the data from the Alpert Arthritis Center to identify groups of joints that contributed similar proportions to the total scores. From this analysis, several schemes were tested on the ARAMIS data. Finally, we chose I modified scheme which was based on the results of the cluster analysis, the frequency of joint involvement, clinical judgment regarding ease and reliability of reading specific joints, and some limited data on the 1327 long-term progression of radiologic lesions. We tested this scheme, using the data from the collaborative study of November 1983 (11). The results indicate that this modified scheme, which eliminates areas that are technically difficult to read and other areas that are infrequently involved, provides an appropriate sample of the joints in the hands and wrists that will accurately represent the radiologic abnormalities of patients with RA . Figure 1. Original scheme. Twenty-seven areas of the hands and wrists scored for erosions (large black dots) and joint space narrowing (parallel lines) in assessing the severity of rheumatoid arthritis. 1328 SHARP ET AL METHODS Source of data. Radiologic scores on 131 patients with RA whose clinical, laboratory, and radiologic data had been entered in the ARAMIS data bank from the Joe and Betty Alpert Arthritis Center, Denver, CO were analyzed. Selection of data on these 131 patients was based on whether hand and wrist films were of sufficient technical quality to allow a reading of all joints specified in the original scheme for scoring erosions. The films were scored according to the method described by Sharp et a1 (7). Briefly, 27 areas of each hand and wrist were scored for erosions and JSN (Figure 1). Erosions were counted when discrete. Surface erosions, Table 1. Description of schemes for scoring erosions and joint space narrowing (JSN) on radiographs of the hands and wrists of patients with rheumatoid arthritis* ~ ~ n Original scheme? Scheme A Scheme B Scheme C Scheme D Scheme E Scheme F Scheme G Scheme H Scheme I Scheme J Scheme K Scheme L Scheme M Scheme N Description ~~ ~~ ~ ~ Areas read for JSN Areas read for erosions n Description 54 8 DIPs, 10 PIPs, 10 MCPs. 10 54 8 DIPs, 10 PIPS. 10 MCBs, 10 CMCs, 12 intercarpal. 2 radioMCPs, 12 carpal bonest, 2 radius, 2 ulnar bones carpal, 2 radioulnar joints 48 Removed from original scheme: R 48 Removed from original scheme: R 5th DIP, L 4th and 5th bIPs, L 5th DIP, L 4th and 5th DIPS, L 5th PIP, R 2nd MCP, R hamate 5th PIP, R 2nd CMC, R hamate-capitate joints bones 45 Same as A, but also removed: R 45 Same as A, but also removed: R 2nd and 4th DIPs, R radius 2nd and 4th DIPs, R radiocarbones pal joints 36 Same as B, but also removed: R 36 Same as B, but also removed: R 2nd MCP, R 3rd CMC. R mul2nd MCP, R 3rd MCB, R multangulars, R lunate, R triquetangular-navicular, R lunatetrum, R capitate, L lunate, L triquetrum, R triquetrum-hacapitate. L hamate bones mate. R capitate-navicular-lunate, L lunate-triquetrum, L capitate-navicular-hate, L hamate-capitate joints 46 Same as original, but all 8 DIPS 46 Same as original, but all 8 DIPs removed removed 44 Same as original, but all 10 MCBs 44 Same as original, but all 10 CMCs removed removed 36 Same as original, but all 8 DIP5 36 Same as original, but all 8 DIPS and all 10 MCBs removed and all 10 CMCs removed 34 Same as F, but also removed: R 34 Same as F, but also removed: R and L capitate bones and L capitate-navicular-hate joints 32 Same as G, but also removed: R 32 Same as G , but also removed: R and L hamate bones and L hamate-capitate joints 30 Same as H, but also removed: R 30 Same as H , but also removed: R and L triquetrum bones and L triquetrum-hamate joints 28 Same as I , but also removed: R 28 Same as I, but also removed: R and L h a t e bones and L lunate-triquetrum joints 20 All joints excluded except the 10 20 All joints excluded except the 10 PIPs and 10 MCPs PIPs and 10 MCPs 27 All joints in L hand excluded; 27 All joints in the L hand excluded joints and areas of R hand in original scheme were included 27 All joints in the R hand excluded 27 All joints in R hand excluded 35 Included were: 10 PIPs, 10 MCPs, 36 Included were: 10 PIPs, 10 MCPs, Rand L 1st MCBs. R and L R and L 3rd, 4th. 5th CMCs, R multangulars (as I unit), R and and L multangular-navicular, R L navicular, R and L lunate, R and L lunate-triquetrum, R and and L triquetrum (and pisiL capitate-navicular-lunate, R form), R and L radius, R and L and L radiocarpal, R and L raulnar bones dioulnar joints * DIP = distal interphalangeal; PIP = proximal interphalangeal; MCB = metacarpal base; MCP = metacarpophalangeal; CMC = carpometacarpal; R = right; L = left. t See Figure 1 for graphic representation. t The greater and lesser multangulars are usually superimposed and are therefore read as 1 unit; for the same reason, the triquetrum and pisiform are read together. SCORING JOINT ABNORMALITIES IN RA 1329 1.1 2nd PIP 1i iilhl ,tn A n MCP MCB L T CARPALS P ~ C RAD. U L N A Figure 3. The frequency of erosions in individual joints of the hands and wrists, as determined by reader I, utilizing data from 131 patients in the Alpert Arthritis Center American Rheumatism Association Medical Information System data bank. R = right (open bars); L = left (closed bars); DIP = distal interphalangeal; PIP = proximal interphalangeal; MCB = metacarpal bases; MCP = metacarpophalangeal; M = multangulars; N = navicular; L = lunate; ‘TP = triquetrum-pisiform; H = hamate; C = capitate; RAD. = radius. Figure 2. Scheme N . Seventeen areas scored for erosion (large black dots), and 18 areas scored for joint space narrowing (parallel lines) in assessing the severity of rheumatoid arthritis. which are rarely discrete, were scored according to the surface area involved. When the erosive process resulted in extensive loss of bone from more than one-half of either articulating bone in a metacarpophalangeal (MCP) or proximal interphalangeal (PIP) joint or a carpal bone, the erosion was scored as 5. JSN was given a score of 1 if it was focal, 2 if narrowing was 4 0 % of the original joint space, and 3 if >SO% of the original joint space; ankylosis was scored as 4. The data for each joint were entered into the Alpert Arthritis Center ARAMIS data bank (12). Erosion scores, JSN scores, and total scores, which were the sum of the erosion and JSN scores, were calculated. The frequency of involvement of individual joints and correlation coefficients were obtained utilizing TOD software programs (13). Since the radiologic data on the films at the Alpert Arthritis Center represent radiologic scores assigned by a single reader, the frequency distribution of specific joint involvement and correlations between scores obtained with the original scheme and scheme N (which will be defined later) were compared for 13 different observers, using data obtained in the collaborative study (11). In that study, 41 films of RA patients were selected to represent a broad distribution of disease severity, ranging from those films that were judged by multiple observers to be within normal limits to films that showed advanced disease. Films were read by 13 different observers using 5 different methods of scoring radiologic abnormalities. Data from this study were entered in a Tandem computer at the University of Colorado Health Sciences Center, Denver, CO. Statistical analysis. The Pearson correlation coefficient was used to compare radiologic scores obtained by different schemes. These correlation coefficients were calculated using TOD (13), SPSS (14), or SAS (1s) software programs. Cluster analysis was done on the Alpert Arthritis Center data bank, using a BMDP program (16). These cluster 1330 SHARP ET AL Table 2. Correlation coefficients comparing candidate schemes with the original scheme for scoring erosions and joint space narrowing (JSN) seen on radiographs of rheumatoid arthritis patients* I- DIP I n MCB Candidate scheme No. of joints or areas Erosions JSN A B C D 48 45 36 46 44 36 34 32 30 28 20 27 21 35 0.9971 0.9938 0.9627 0.9899 0.9984 0.9860 0.9844 0.9799 0.9723 0.9595 0.8108 0.9692 0.9736 0.9802 0.9969 0.9939 0.9778 0.9891 0.9927 0.9829 0.9781 0.9714 0.9657 0.9559 0.9028 0.9584 0.9621 0.9816 E F G H I J K L M N * Data are from the Alpert Arthritis Center American Rheumatism Association Medical Information System data bank. Correlation coefficients were calculated between t h e original erosion or JSN scores and scores derived from the modified schemes. 1.1 2nd 3rd MCP 4th 6lh M N L T P CARPALS n c RAD RAD. CARPAL ULNAR Figure 4. The frequency of individual joint involvement by joint space narrowing in the hands and wrists, as determined by reader 1, utilizing data from 131 patients in the Alpert Arthritis Center American Rheumatism Association Medical Information System data bank. M = multangular-navicular joint: N = navicular-hate joint; L = lunate-triquetrum joint; TP = triquetrum-pisiform-hamate joint; H = hamate-capitate joint; C = capitate-navicular-hate joint; RAD. CARPAL = radiocarpal joint; RAD. ULNAR = radioulnar joint. See Figure 3 for other abbreviations. following 4 areas in the wrist were scored as 1 if abnormal: I ) The first metacarpal base was examined for erosions, and the third, fourth, and fifth carpometacarpal (CMC) joints were examined for narrowing; 2 ) The multangulars, navicular, lunate, and triquetrum and pisiform were examined for erosions, and t h e multangular-navicular, lunate-triquetrum, capitate-navicular-hate were examined for narrowing; 3) The radius was examined for erosion, and the radiocarpal joint was examined for narrowing; 4)The ulna was examined for erosion, and the radioulnar joint was examined for narrowing. RESULTS analyses were done separately on erosion scores and JSN scores. Schemes. Based on the cluster analysis, frequency of joint involvement, and experience regarding technical factors in reading specific joints, various combinations of joints, hereafter called schemes, were selected for further testing. These schemes are given in Table 1 . One group of schemes was designed by subtracting progressively more joints from groups identified by cluster analysis. Another group of schemes was formed by removing groups or combinations of groups of joints. Scheme K excluded all joints except the 10 MCPs and 10 PIPS; scheme L excluded all joints in the left hand; scheme M excluded all joints in the right hand; scheme N excluded all distal interphalangeal (DIP) joints and selected areas in the wrists. Included in scheme N were 17 areas scored for erosions and 18 areas scored for JSN in each hand (Figure 2). The method used for obtaining the count of abnormal joints defined an abnormal joint as one which showed an erosion or JSN. Each MCP, each PIP, and each of the Utilizing data from 131 patients included in the Alpert Arthritis Center ARAMIS data bank, the frequencies of individual joint involvement by erosions and JSN were determined; these are depicted in Figures 3 and 4. Abnormalities were most frequently observed in t h e MCP, PIP, radiocarpal, and intercarpal joints, and the third, fourth, and fifth CMC joints. To test whether multiple observers judged the same areas to be involved, we tabulated the frequency of involvement by erosions and JSN as assessed by 11 readers who participated in the collaborative study. The frequency of abnormalities in individual joints, based on a single reader, was below the median frequency of involvement derived from the scoring by I f observers, with the difference from the median ranging from &29% (data not shown). Thus, it can be inferred that the frequency data depicted in Figures 3 and 4 represent conservative estimates. 1331 SCORING JOINT ABNORMALITIES IN RA Table 3. Correlation coeficients and ratios between total scores derived from scheme N and scores derived from the original scheme Source of scores n AAC ARAMIS data bank* 131 41-film set, reader no.t I 41 3 41 4 41 5 41 7 41 8 39 9 41 10 12 13 15 41 41 41 41 Correlation coefficient Ratio Range 0.9891 0.9228 0-1.0 0.9951 0.9971 0.9923 0.9951 0.9913 0.9937 0.9845 0.9936 0.9920 0.9807 0.9806 0.8778 0.9724 0.8121 0.8469 0.6679 0.9158 0.8044 0.7667 0.8382 0.6557 0.8372 0-1.0 0-1.0 0.5-1.0 0-1.0 0.188-1.0 0.677-1.0 0.444-1 .0 0.364-1.0 0.333-1.0 0.368-0.8201 0.659-1 .0 * Data were derived from 131 films in the Alpert Arthritis Center American Rheumatism Association Medical Information System (AAC ARAMIS) data bank, read by a single observer. t Data were derived from a collaborative project in which 1 1 observers read a standardized set of 41 hand and wrist study films. Readers 2 and 6 were not included here since the areas they read to obtain the original scores were almost identical to the areas included in the modified scores of the other readers. Reader 1 1 was not inclulded since he did not complete the reading of the set. Reader 14 was not included because he used an electronic device for reading joint space narrowing. After the cluster and frequency analyses to reduce the number of joints to be read were performed, the various schemes selected were tested by corriparing the total scores derived for each scheme with the total scores taken from the original scheme. Correlation coefficients were calculated, and the ratio of the 2 scores (score from the modified scheme divided by the score from the original scheme) was determined using the Alpert Arthritis Center data. The correlation coefficients are shown in Table 2. Taking into consideration the data derived from the cluster analysis and various candidate schemes, the frequency of involvement, and the ease of reading a joint, which is primarily related to the projection of the ,area on standard films, 1 modified scheme (scheme N) was chosen for further testing (Figure 2). In scheme N , 17 areas in each hand and wrist were read for erosions, and 18 areas were read for JSN. A total score was derived by summing all of the erosion and JSN scores for these areas. The suitability of this total score as a representation of the severity of radiologic changes in all of the joints of the hands and wrists was tested by calculating a correlation coefficient, comparing the total scores calculated for scheme N and the total scores obtained with the original scheme. This correlation coefficient, calculated on the Alpert Arthritis Center ARAMIS Table 4. Comparison of joint groups included in and excluded from scheme N* Frequency of involvement, 9? (range o f . medians) Joints excluded Erosions DIPs MCBs Carpals Mean all areas Joint space narrowing DIPs CMCs Intercarpals Mean all areas Joints included Erosions MCPs PIPS Wrists Mean all areas Joint space narrowing MCPs PIPS Wrists Mean all areas Coefficient of variation (SD + mean) 5-13.0 0-1 8.5 11-23.5 14.4 78-145 70-2 17 74-1 I 1 104.8 5-22.0 10-38.5 17-47.0 24.4 80-124 44- 144 44-78 84.6 27.0-66 15.0-39 12.5-53 37.5 22-69 34-77 27-86 51.1 17.0-56 8.5-36 17.0-55 32.1 30-89 56-123 27- 102 59.0 * Data are from scores of 9-1 I observers who read the 41-film study set of nonrandomly selected films. DIP = distal interphalangeal; MCB =. metacarpal base; CMC = carpometacarpal; MCP = metacarpophalangeal. data, was 0.9891 (Table 3). The ratio of the scheme N total score to the original score was 0.9228. This ratio indicates that 4% of the original total score was contributed by the areas eliminated in scheme N. Scheme N was tested further, using the scores of the 41-film study set read by 11 observers. Intraobserver correlation coefficients, comparing the modified scores, based on scheme N , with the scores derived from the original scheme, were above 0.9800 for 11 readers (Table 3). The ratios of the modified scores to the original scores varied between 0.6557 and 0.9724 and averaged 0.8177. These ratios indicate that Table 5. Interobserver correlation coefficients, original scores compared with scheme N scores Range Original total scores 0.736-0.956 Scheme N total scores* 0.752-0.969 ~~ * ~ ~ 0 . 8 5 0 20.900 50 60 31 38 20.950 4 6 ~ In 71 of 78 comparisons, interobserver coefficients were higher when total scores derived from scheme N were used than when the original total scores were used. 1332 SHARP ET AL Table 6. Ratios of total scores derived from scheme N to total scores derived from original scheme, by patient group stratified by disease severity* Range Patients with original of scores >O All patientst originaI total Mean Mean Patient g r o w score n ratio SEM n ratio SEM Entire group Greatest severity Intermediate severity Least severity 0-151 >21 4-2 1 <4 110 44 40 26 0.9080 0.8756 0.9172 0.9487 0.0161 0.01695 0.0304 0.0401 131 44 40 47 0.9228 0.8756 0.9172 0.9716 0.01385 0.01695 0.03041 0.02228 * Data are from the Alpert Arthritis Center American Rheumatism Association Medical Information System data bank. t Technically, 0 divided by 0 is a nonentity. However, for purposes of this calculation, since a 0 modified score found with a 0 original score is an identical finding, the ratio was considered to be 1 for those cases. 1 observer, on reading the selected films in the study set, attributed an average of 35% of abnormalities for the entire set to those areas not included in scheme N, while another observer attributed <3% of abnormalities to those areas; the mean was 18%. The variability in interpreting these areas is further illustrated in Table 4, which compares the frequency and coefficients of variation of erosion scores and JSN scores for the areas retained in scheme N with those areas eliminated. The frequency of involvement was relatively low for the DIP joints, but much higher for most of the areas in the wrists. However, the coefficients of variation were much greater for the eliminated areas than for the areas included in scheme N. Interobserver correlation coefficients were calculated for the scores of all 13 readers on the 41-film study set, and showed that 71 of 78 correlations were higher when the total scores based on scheme N were Table 7. Correlation coefficients of total scores derived from scheme N compared with total scores derived from original scheme, by patient group, stratified by disease severity* Patient group n Correlation coefficient Entire group Greatest severity (total score >21) Intermediate severity (total score 4-21) Least severity (total score <4) Patients with disease duration >I0 years 131 0.9891 44 0.9740 40 0.9450 47 0.9662 30 0.9908 * Data are from the Alpert Arthritis Center American Rheumatism Association Medical Information System data bank. used than when the total scores based on the original scheme were used (Table 5 ) . Since scheme N might perform well for examination of data from films in the study set, which represented a broad spectrum of disease severity, yet might not be an accurate instrument for measuring abnormalities in patients with more advanced disease, the data from the Alpert Arthritis Center ARAMIS data bank were stratified into 3 groups of increasing disease severity. As expected, in patients with the most severe disease, the frequency of erosions and JSN was greater in the joints excluded from the new scheme; this is shown by the mean ratios of modified total scores to original total scores. These ratios, Table 8. Correlation coefficients and ratios between counts of involved joints for areas in scheme N and original total scores* Source of scores n AAC ARAMIS data bank 131 41-film set, reader no. I 41 4 41 5 41 6 40 7 41 8 39 9 41 10 41 12 41 13 41 15 41 Correlation coefficient Ratiot 0.8887 0.5791 0.9392 0.9488 0.9348 0.8735 0.8752 0.8825 0.8912 0.8673 0.9451 0.8866 0.8621 0.4753 0.3192 0.4317 0.3668 0.2697 0.4256 0.3213 0.2943 0.4317 0.2348 0.2957 Range 0-1.0 0-1.0 0.141-1.0 0-1.0 0-0.625 0.125-0.833 0-1.0 0.108-1.0 0.125-0.563 0.154-1.0 0.129-0.452 0.144-0.667 * A joint was counted as involved if either erosion or joint space narrowing was present. AAC ARAMIS = Alpert Arthritis Center American Rheumatism Association Medical Information System (131 films, read by a single observer). t Ratio was calculated between joint count and original total score (count + total score). SCORING JOINT ABNORMALITIES IN RA calculated for the 3 groups, demonstrated that as disease severity increased, a decreasing proportion of the ‘totalscore was represented in the scheme N scores (Table 6 ) . Nevertheless, the correlation coefficients were similar for each disease-severity subset (Table 7). To test whether the scoring method could be further simplified, a count of abnormal joints was performed, assigning a value of 1 for each joint or area that showed either erosion or JSN. The joints and areas counted were those used in scheme N. Areas in the wrists were divided into 4 groups so that the total weight assigned to each wrist, if a minimum of 1 bone orjoint in each group was involved, was 4. Correlation coefficients between these counts of involved joints and the original total scores were calculated on the intr,aobserver data of 1 1 readers. These correlation coeficients varied between 0.8621 and 0.9488. The ratio of counts to total scores ranged between 0.2348 and 0.4753, with a mean of 0.3515 (Table 8). DISCUSSION Reading 54 areas separately for erosions and joint space narrowing, i.e., 27 areas in each hand and wrist, can be tedious and time consuming. Therefore, we have explored the possibility of simplifying the procedure by selecting a smaller number of areas. The prolblem is primarily one of sampling; namely, do the areas chosen accurately reflect the extent of changes in the entire hand and wrist? This is not a simple question. For example, there are more than 8 million combinations that can be formed by selecting any 17 of the 27 total joints, and an even larger number of combinations can be formed by selecting fewer than 17 joints. Therefore, after preliminary analysis by several methods, we arbitrarily selected a scheme. Cluster analysis was performed to identify groups of joints that contributed a similar proportion of the total scores. Frequency analysis of joint involvement was performed to determine which joints contributed the most to the radiologic scores. Based on this information and on Iclinical judgment regarding the technical problems involved in reading specific joints, a series of modified schemes was tested by calculating correlation coefficients between newly derived scores and the original score. Finally, scheme N , which eliminated more than one-third of the original joints scored, was chosen for further study. This modified scheme was then tested on 2 data sets, the Alpert Arthritis Center ARAMIS data bank, representing radiologic scores on films from 1333 131 patients read by a single observer, and another set of data representing radiologic scores of 13 different observers on a study set of 41 selected films. Correlation coefficients were used to test how well scheme N represented the overall score. Although no standards have been established as to what is a satisfactory level of reproducibility, intraobserver correlation coefficients between scores derived from scheme N and the original scheme were above 0.9800, indicating a high degree of similarity of the scores derived from the 2 schemes. Furthermore, correlation coefficients between observers were improved when the modified scheme was used, suggesting that those areas which were excluded from scheme N were read with less consistency among the 13 observers than those areas which remained. This result is not unexpected since the original scheme included DIPS with the understanding that the observer would distinguish between erosive osteoarthritis and the lesions of RA. By eliminating these joints, the inconsistencies that might arise among observers’ interpretations were also eliminated. The same argument applies to several areas in the wrists that are difficult to read because projection in standard posteroanterior and oblique films is not consistent; for example, the navicular-lunate joint and the hamate-capitate joints are rarely “opened up” in standard films. That, in fact, there was greater inconsistency in reading the areas of the original scheme that were not included in scheme N is demonstrated by the greater coefficients of variation for many of those areas (Table 4). Comparison of scores derived by the 2 schemes for patients who had been stratified into subsets according to the severity of radiologic evidence of involvement, showed that a higher proportion of scores were derived from those areas eliminated by scheme N in patients with the most severe disease. This observation suggests 2 possible interpretations. First, the DIP, selected metacarpal bases, CMC, and intercarpal joints may not be involved proportionally, compared with MCP and PIP joints in patients with varying severity of disease. In this case, the consequence of eliminating these areas from the new scheme would be to reduce the sensitivity of the radiologic scores in deteci ing progression of disease among patients whose disease was already severe at the baseline observation. Alternatively, observers may be reluctant to attribute a given erosion or narrowed joint space in the DIP joints and, perhaps, even in the CMC and some 1334 intercarpal joints, to RA if there is no involvement or if there is limited abnormality in the MCP and PIP joints. In this case, the modified scheme should increase the specificity and precision of scoring. It is noteworthy that Larsen et a1 (8) and Genant (9) do not include DIP joints and they limit the wrist areas included in their schemes; Bluhm et a1 have also eliminated the DIP joints in their scheme (10). Some have proposed that eliminating further areas and using an even smaller number of joints would be desirable. For example, Bluhm et a1 have suggested reading only 16joints in each hand and wrist for narrowing, although they proposed reading 23 areas for erosions (10). At present, there are serious reservations about oversimplifying the scheme. If sensitivity in measuring the progression of disease is of paramount importance-for example, in a drug trialany further reduction in the number of joints read might significantly reduce the sensitivity of detecting change. More data on longitudinal studies of untreated patients or patients treated with the usual and customary regimens will be required to assess how extensive this loss in sensitivity might be. Others have proposed that the wrist should be scored as a single unit. Based on the number of articulations in the wrist, this seems inappropriate. There are 15 bones involved in the articulations in the wrist joint. Considering that 10 scores are derived from the 10 bones represented in the articulations of the 5 MCP joints and 10 scores from the 10 bones of the 5 PIP joints in each hand, representing the wrist with 2 scores-a single score for erosions and another score for narrowing-would be grossly disproportionate. The modified scheme proposed here, which was derived by selecting areas that are frequently involved and are usually well projected in standard films, results in 15 scores for the wrist, which is 1.5 times the number of scores for the MCPs and for the PIPS. Thus, scheme N represents a balance that reflects the number of joints in each area. Use of this modified scheme should reduce the time required to score hand and wrist films. Although more than 80% of the original total score was derived from the areas included in scheme N, elimination of those areas which are difficult to read because they are often technically poorly projected, and of other areas which may require interpretation as to the nature of the changes, should speed the reading process significantly. Again, it should be emphasized that selection of joints to read is a highly arbitrary process, primarily because of the extremely large number of possible combinations. Proof that one selection is the “most suitable” scheme for multiple circumstances is not within the realm of practical possibility. It should therefore be recognized that the choice of scheme N , which incorporates 70 observations (34 erosion scores and 36 JSN scores), is a compromise to allow for a more rapid reading, using a method which demonstrates better interobserver agreement than the original scheme, but still incorporates enough areas to be sensitive to minor progression of disease. Proof that eliminating approximately one-third of the areas does not seriously impair the sensitivity of the method for detecting disease progression will require field testing in a therapeutic trial or study of the natural history of RA . A more abbreviated scheme, which in essence reduces the scale and therefore the sensitivity of detecting change, might be adequate for some purposes, such as describing outcome in general terms for a large, population-based sample, but might be an extremely expensive shortcut in a drug trial if the number of patients studied had to be greatly expanded or the length of the study had to be extended. For example, the joint count method described here, although clearly not as sensitive to change as the scoring method, might be appropriate for the general followup of patients not in special studies, but it would be inappropriate for studies that would benefit from the more precise data acquired with the expanded scale provided by the scoring system. Finally, it should be pointed out that this study does not deal with methods of scoring individual joints. That is an issue that has not yet been resolved. Steinbrocker 0, Traeger CH, Batterman RC: Therapeutic criteria in rheumatoid arthritis. JAMA 140:659-665, 1949 Atlas of Standard Radiographs of Arthritis: The Epidemiology of Chronic Rheumatism. Vol. 2. Philadelphia, FA Davis, 1963 Berens DL, Lin RK: Roentgen Diagnosis of Rheumatoid Arthritis. Springfield, IL, Charles C. Thomas, 1969 Engel A, Roberts J, Burch TA: Rheumatoid Arthritis in Adults: United States, 1960-1962, National Health Services Publications, series 1 1 , no. 17. Government Printing Office, 1966 SClORING JOINT ABNORMALITIES IN RA 5. Larsen A: A radiological method for grading the severity of rheumatoid arthritis (thesis). University of Helsinki, Finland, 1974 6. Severs K: The rheumatoid factor in definite rheumatoid arthritis. Acta Rheumatol Scand [Suppl] 9: 1-28, 1965 7. Sharp JT, Lidsky MD, Collins LC, Moreland J: Methods of scoring the progression of radiologic changes in rheumatoid arthritis: correlation of radiologic, clinical and laboratory abnormalities. Arthritis Rheum 14:706720, 1971 8. Larsen A, Dale K , Eck M: Radiographic evaluation of rheumatoid arthritis and related conditions by standard reference films. Acta Radio1 [Diagn] (Stockh) 18:481491, 1977 9. Genant HK: Methods of assessing radiographic change in rheumatoid arthritis. Am J Med 74:35-47,1983 10. Bluhm GB, Smith DW, Mikulashek WM: A radiologic method of assessment of bone and joint destruction in rheumatoid arthritis. Henry Ford Hosp Med J 31: 152-161, 1983 1335 11. Sharp JT, Bluhm GB, Brook A, Brower AC, Corbett M, Decker JL, Genant HK, Gofton JP, Goodman N , Larsen A, Lidsky MD, Pussila P, Weinstein AS, Weissman BN, Young DY: Reproducibility of multiple-observer scoring of radiologic abnormalities in the hands and wrists of patients with rheumatoid arthritis. Arthritis Rheum 28 16-24, 1985 12. The Computer Committee of the American Rheumatism Association: A uniform database for rheumatic diseases. Arthritis Rheum 22:1029-1033, 1979 13. McShane DJ, Harlow A, Kraines RG, Fries JF: TOD: a software system for the ARAMIS data bank. Computer 12 34-40, 1979 14. Nie HH, Hull CH, Jenkins JG, Steinbrenner K , Bent DH: Statistical Package for the Social Sciences. First edition. New York, McGraw-Hill, 1975 IS. Helwig JT, Council KA: SAS Users Guide. Cary, NC, SAS Institute, Inc., 1979 16. Dixon WJ, Brown M: Biomedical Computer Programs. Berkeley, University of California Press, 1979
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