Examining radiographic outcomes over time.

Statistical analysis plays a critical role in data interpretation in all fields and particularly so for clinical data where important treatment decisions are made. We provide here an in-depth and illustrative analysis to examine patterns and radiographic scores in an early disease rheumatoid arthritis cohort over a 3-year follow-up period. The total Sharp radiographic scores were interpolated from the rates at 6 months, 1, 2, and 3 years and were transformed to count data after rounding. The generalized estimating equations approach and two-part models were applied to analyze the longitudinal radiographic scores using the clinical, demographic, and therapeutic characteristics of the patients after adjusting for the pattern outcomes. Total Sharp scores were modeled, assuming that they were Poisson distributed or had a negative binomial distribution with either an AR(1) working correlation matrix or an exchangeable working correlation matrix. To account for the excessive zero counts, we used two-part models that include the zero-inflated Poisson and the zero-inflated negative binomial to fit the data. This is an innovation because two-part models have not been used in rheumatology even though they are highly appropriate for analyzing data from rheumatic studies. In addition, we analyzed data using generalized estimating equations and compared results from different models using formal statistical goodness-of-fit criteria and arrive at the best model for predicting purposes.

CT of rib lesions.

OBJECTIVE: This article discusses how ribs are involved in a variety of traumatic, metabolic, inflammatory, neoplastic, and congenital disorders. CONCLUSION: We review the normal anatomy pertinent to rib imaging and illustrate the key features of a variety of rib lesions, emphasizing the diagnostic value of CT.

Comparison of composite measures of disease activity in an early seropositive rheumatoid arthritis cohort.

OBJECTIVE: To evaluate concordance and agreement of the original DAS44/ESR-4 item composite disease activity status measure with nine simpler derivatives when classifying patient responses by European League of Associations for Rheumatology (EULAR) criteria, using an early rheumatoid factor positive (RF+) rheumatoid arthritis (RA) patient cohort. METHODS: Disease-modifying anti-rheumatic drug-naïve RF+ patients (n = 223; mean duration of symptoms, 6 months) were categorised as ACR none/20/50/70 responders. One-way analysis of variance and two-sample t tests were used to investigate the relationship between the ACR response groups and each composite measure. EULAR reached/change cut-point scores were calculated for each composite measure. EULAR (good/moderate/none) responses for each composite measure and the degree of agreement with the DAS44/ESR-4 item were calculated for 203 patients. RESULTS: Patients were mostly female (78%) with moderate to high disease activity. A centile-based nomogram compared equivalent composite measure scores. Changes from baseline in the composite measures in patients with ACRnone were significantly less than those of ACR20/50/70 responders, and those for ACR50 were significantly different from those for ACR70. EULAR reached/change cut-point scores for our cohort were similar to published cut-points. When compared with the DAS44/ESR-4 item, EULAR (good/moderate/none) percentage agreements were 92 with the DAS44/ESR-3 item, 74 with the Clinical Disease Activity Index, and 80 with the DAS28/ESR-4 item, the DAS28/CRP-4 item and the Simplified Disease Activity Index. CONCLUSION: The relationships of nine different RA composite measures against the DAS44/ESR-4 item when applied to a cohort of seropositive patients with early RA are described. Each of these simplified status and response measures could be useful in assessing patients with RA, but the specific measure selected should be pre-specified and described for each study.

Classifying radiographic progression status in early rheumatoid arthritis patients using propensity scores to adjust for baseline differences.

Various methods are used to measure radiographic joint damage in patients with rheumatoid arthritis (RA), but determining proportions of responsive patients is difficult. A key problem in observational studies when assessing damage outcomes is incorporating time to treatment initialization and adjusting for observed baseline differences. We examined five different definitions to select an appropriate index to classify radiographic damage in RA patients as progressive or nonprogressive. In addition, we compared different times from symptom onset to treatment and their effects on patient radiographic categorization. Propensity scores to adjust for baseline differences, including time since symptom onset, were used to match those treated early with those treated later using the stratification, radius, nearest neighbor and kernel methods. The mean effect of treatment on the treated was computed for each matching method. Observational data were analyzed for 185 early RA patients from the Western Consortium study followed six to sixty months (mean thirty-one months). For the selected index, 75 patients were categorized as nonprogressors; they had significantly lower disease activity, more clinical improvement and were treated earlier than the progressors. Of those treated within three months of symptom onset, 57% were classified as radiographically progressive versus 35% of those treated later (P = 0.0058). However, after propensity score adjustment for baseline differences, we noticed nonsignificant (P > 0.05) nonprogression in patients given earlier treatment. We conclude that propensity score analysis reduced but did not remove all bias.

Patterns of radiographic outcomes in early, seropositive rheumatoid arthritis: a baseline analysis.

We examine radiographic profile patterns using clustering algorithms to assess progression rates at set time intervals in a rheumatoid arthritis (RA) observational study. Hands/feet radiographic scores were analyzed for 190 early, seropositive RA patients with ≥ 3 radiographic observations from a prospective cohort. Assessments at 6 months, 1 year, and yearly thereafter were requested for demographic, therapeutic, functional, laboratory, radiographic, and clinical data. Progression rates for the total sharp scores [erosion (E)+joint space narrowing (JSN)] were interpolated for intervals of 0 to 6 months, 6 month-1 year, 1-2 years, and 2-3 years past first radiographic observation. Patients were grouped on their sets of rates by K-median clustering algorithms, and categorical group membership was regressed onto baseline characteristics using multinomial models. The number of clusters was determined using one-way MANOVA, and baseline differences across clusters by Kruskal-Wallis tests. The median RA duration was 6.1 months, mean age 52 years, median disease activity score (DAS) 4.6, mean radiographic observations 4.6 (range 3-8) for this mostly female (77%), Caucasian (78%) sample. 3 patterns were determined: increasing (n = 41; 22%), increasing then decreasing (n = 41; 22%), and flat (n = 108; 57%). High baseline C-reactive protein was associated with a worsening radiographic progression (p < 0.005), as were HAQ-DI (p = 0.07), JSN (p < 0.01), and E (p = 0.03). Our conclusions are that radiographic progression patterns graphically supplement traditional linear rates, and are flexible to use in both clinical and observational studies. The identified clusters and rates may correspond better with clinical status and treatment over the disease course than linear progression rates alone.

Equivalent responses to disease-modifying antirheumatic drugs initiated at any time during the first 15 months after symptom onset in patients with seropositive rheumatoid arthritis.

OBJECTIVE: To evaluate responses by time to initiation of nonbiologic disease-modifying antirheumatic drugs (DMARD) in a DMARD-naive cohort of patients with early seropositive rheumatoid arthritis (RA). METHODS: Subjects were categorized by the time from symptom onset to the first DMARD use (median 5.7 months, range 0.6-15.9). Subjects who started their first DMARD within 5 months of symptom onset were compared to subjects who started after 5 months. Disease Activity Scores (DAS-44) and total Sharp Score (TSS) progression rates were analyzed using Wilcoxon rank-sum and chi-square tests; multiple linear regression analysis adjusted for potential covariates. The slope of the least-squares regression line was calculated to estimate the annualized TSS progression rates. RESULTS: Of 233 RA patients, 76% were female and mean age was 50 (SD 13) years. At DMARD start, DAS-44 was similar in all subsets within the 0.6 to 15 months' duration between symptom onset and DMARD initiation. Erosion scores tended to be higher in those who started DMARD later, but Health Assessment Questionnaire-Disability Index (HAQ-DI) scores were higher in those who started DMARD earlier. During the 2 years after DMARD initiation, improvements in HAQ-DI and DAS-44 were similar in the various duration subsets, with about 25% ever achieving DAS remission (DAS < 1.6). Radiographic progression tended to be numerically but not statistically more rapid in the earlier subsets. CONCLUSION: Following initiation of nonbiologic DMARD therapy at various times within 15 months of symptom onset, improvements of DAS-44, HAQ-DI, remission rate, and radiographic progression rate were similar, although higher baseline erosion scores were present in those with later initiation of DMARD.

Evaluation of the preliminary definitions of minimal disease activity and remission in an early seropositive rheumatoid arthritis cohort.

OBJECTIVE: To evaluate published proposed definitions of minimal disease activity (MDA) and remission in patients with early rheumatoid arthritis (RA). METHODS: The cohort comprised disease-modifying antirheumatic drug (DMARD)-naive patients with early seropositive active RA (n = 200) treated with traditional DMARDs in the prebiologic era. MDA definitions included Disease Activity Score in 28 joints (DAS28)

Association of tumor necrosis factor alpha polymorphism, but not the shared epitope, with increased radiographic progression in a seropositive rheumatoid arthritis inception cohort.

OBJECTIVE: To determine whether the tumor necrosis factor alpha (TNFA) -308 guanine-to-adenosine polymorphism and/or the shared epitope (SE) is associated with radiographic damage in patients with early rheumatoid arthritis (RA). METHODS: The cohort consisted of 189 patients with early seropositive RA (median 5.6 months since symptom onset) who had active disease, no previous disease-modifying antirheumatic drug treatment, and >or=2 sets of scored radiographs of the hands/wrists and forefeet. TNFA -308 polymorphism was analyzed by polymerase chain reaction pyrosequencing. The SE was defined as presence of any 1 of the following HLA-DRB1 alleles: *0101, *0102, *0401, *0404, *0405, *0408, *0410, *1001, *1402, or *1406. Radiographic progression was assessed by the total Sharp score. RESULTS: Using a weighted least-squares regression analysis, patients with the -308 TNFA AA plus AG genotypes (n=49) had significantly higher rates of progression in erosion scores (median 0.84 versus 0.48 units/year), joint space narrowing (JSN) scores (0.42 versus 0.04), and total Sharp scores (1.70 versus 0.61) compared with patients with the TNFA GG genotype (n=140). Presence of the SE (n=137) was associated with significantly lower progression rates (per year) for total Sharp scores (median 0.9 versus 1.25 units/year) and JSN scores (0.04 versus 0.41), but not for erosion scores (0.50 versus 0.61) compared with patients without the SE (n=52). In a least-squares multiple linear regression model, the presence of the AA plus AG genotypes was associated with a significantly higher progression rate after adjusting for the presence of the SE, interaction between the SE and the AA plus AG genotypes, baseline log C-reactive protein level, Health Assessment Questionnaire Disability Index, total Sharp score, swollen joint count, and presence of osteophytes (osteoarthritis). There was a strong linkage disequilibrium between DRB1*0301 and TNFA polymorphism (D'=0.84, r2=0.45, P<0.001). CONCLUSION: This study showed an association between the TNFA -308 polymorphism and progression of radiographic damage in patients with early seropositive RA. This association appeared to be independent of the SE, but might be dependent on other genetic variants in linkage disequilibrium with the -308 TNFA A allele and DRB1*0301. Further studies should be conducted to validate these results in both longitudinal observational cohorts and randomized clinical trials.

Increased radiographic damage scores at the onset of seropositive rheumatoid arthritis in older patients are associated with osteoarthritis of the hands, but not with more rapid progression of damage.

OBJECTIVE: To investigate the impact of patient age at symptom onset on radiographic joint damage at study entry, and on subsequent progression of damage in a cohort of patients with early seropositive rheumatoid arthritis (RA). METHODS: We studied 186 patients with RA of <15 months' duration. All patients had active disease and had not received disease-modifying antirheumatic drugs. At study entry and during followup, total Sharp scores (TSS), RA-associated joint space narrowing (RA-JSN), and erosions were determined on hand and foot radiographs. Baseline radiographs were also scored for osteoarthritis (OA)-related JSN (OA-JSN) and osteophytes. Older patients (>55 years) and younger patients (

Classifying structural joint damage in rheumatoid arthritis as progressive or nonprogressive using a composite definition of joint radiographic change: a preliminary proposal.

OBJECTIVE: To categorize radiographic joint damage as progressive or nonprogressive in individuals with rheumatoid arthritis (RA) participating in clinical studies. METHODS: Using the total Sharp radiographic damage score, erosion score, and joint space narrowing (JSN) score for 751 serial films of the hand/wrist and forefoot obtained from 190 patients with early RA during 6-60 months of followup (mean 31 months), various threshold values for progression of joint damage were evaluated singly and in various combinations. For each patient, the progression rate was estimated from the linear regression line for all available radiographic time points. After preliminary screening, 23 candidate definitions were tested to select a definition that discriminated well between radiographic progression and radiographic nonprogression. RESULTS: The definition selected describes radiographic nonprogression in individual patients as an increase of < or =0.1 in the standardized response mean of the trimmed population (the central 95% of patients) for > or =5 of 6 change measures (erosion scores and JSN scores for the fingers, wrists, and feet). Using this definition, 59% of the 190 patients with early RA were defined as having nonprogressive radiographic damage. Moreover, 95% of 95 patients with progression of the total Sharp score at or below the median and 24% of 95 patients with progression of the total Sharp score above the median were defined as having nonprogressive joint damage (chi(2) = 98, P < 0.0001), as were 97% of patients in the lowest quintile of total Sharp score progression rates and none of the patients in the highest progression quintile. Patients defined as nonprogressors had significantly lower baseline levels of C-reactive protein and lower erythrocyte sedimentation rates compared with patients defined as progressors, and those patients in the nonprogressive joint damage group more frequently had American College of Rheumatology 20% and 50% improvement criteria responses, "good" improvements (decrease of > or =1.2) in the Disease Activity Score, and > or =50% decreases in the swollen joint counts during the first 2 years of followup. CONCLUSION: RA joint damage in an observational cohort can be classified as progressive or nonprogressive with the use of a composite definition. Validation and/or refinement of this definition is needed by utilizing the data from controlled clinical trials that compare placebo with active treatment.

Correlation of single time-point damage scores with observed progression of radiographic damage during the first 6 years of rheumatoid arthritis.

OBJECTIVE: Aggressive treatment of early rheumatoid arthritis (RA) is recommended to prevent irreversible joint damage. We evaluated the usefulness of single time-point joint radiographs for deciding whether early RA is erosive or nonerosive. METHODS: In an observational study, 179 patients with recent onset of RA symptoms (median 5.1 mo), positive rheumatoid factor, and active polyarthritis had 2 to 8 radiographic observations of hands, wrists, and forefeet during 6 to 60 months of followup. Linear regression lines for all available radiographs were used to determine progression rates of total Sharp score (TSS), erosion score (ES), and joint space narrowing score (JSNS) of each patient. RESULTS: Using the average of 2 readers' scores, intraclass correlation coefficient was 0.97 and smallest detectable difference was 3.07 for ES, 0.93 and 7.52 for JSNS, and 0.90 and 12.71 for TSS. Mean progression rates per year were 1.20 (ES), 0.67 (JSNS), and 1.85 (TSS). Single time-point radiographs taken within 6 months of symptom onset did not correlate with progression rates (r = 0.01 to 0.07); between 7 and 18 months correlations were weak (r = 0.23 to 0.35), but were better for ES between 19 and 72 months (r = 0.60 to 0.81). Among 53 patients (31%) with no progression of TSS, only 10 of them had zero scores at baseline. Among all 630 radiographs with TSS > or = 1, 25% were associated with progression rates < or = 0. CONCLUSION: Erosion scores of single radiographic examinations done > 18 months after onset of RA symptoms correlated with progression rates, but earlier radiographs did not sufficiently predict erosive or nonerosive status to guide disease modifying antirheumatic drug treatment decisions.