Role of erosions typical of rheumatoid arthritis in the 2010 ACR/EULAR rheumatoid arthritis classification criteria: results from a very early arthritis cohort.

OBJECTIVE: To determine how the European League Against Rheumatism (EULAR) definition of erosive disease (erosion criterion) contributes to the number of patients classified as rheumatoid arthritis (RA) according to the 2010 American College of Rheumatology/EULAR RA classification criteria (2010 RA criteria) in an early arthritis cohort. METHODS: Patients from the observational study Norwegian Very Early Arthritis Clinic with joint swelling ≤16 weeks, a clinical diagnosis of RA or undifferentiated arthritis, and radiographs of hands and feet were included. Erosive disease was defined according to the EULAR definition accompanying the 2010 RA criteria. We calculated the additional number of patients being classified as RA based on the erosion criteria at baseline and during follow-up. RESULTS: Of the 289 included patients, 120 (41.5%) fulfilled the 2010 RA criteria, whereas 15 (5.2%) fulfilled only the erosion criterion at baseline. 118 patients had radiographic follow-up at 2 years, of whom 6.8% fulfilled the 2010 RA criteria and only one patient fulfilled solely the erosion criterion during follow-up. CONCLUSION: Few patients with early arthritis were classified as RA based on solely the erosion criteria, and of those who did almost all did so at baseline.

Disease Characteristics and Rheumatoid Arthritis Development in Patients with Early Undifferentiated Arthritis: A 2-year Followup Study.

OBJECTIVE: To examine the 2-year disease course in patients with undifferentiated arthritis (UA) focusing on fulfillment of the 2010 American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) rheumatoid arthritis (RA) classification criteria. METHODS: Data were provided by the Norwegian Very Early Arthritis Clinic study, which included patients presenting with ≥ 1 swollen joint of ≤ 16 weeks' duration. UA was defined as patients not fulfilling the 2010 ACR/EULAR RA criteria and who did not have a clinical diagnosis other than RA at baseline. The main outcome was fulfillment of the 2010 RA criteria. Secondary outcomes were disease-modifying antirheumatic drug (DMARD) use, resolution of synovitis without use of DMARD during followup, and final clinical diagnosis. RESULTS: We included 477 patients with UA of whom 47 fulfilled the 2010 ACR/EULAR RA criteria during followup (UA-RA) and 430 did not (UA-non-RA). Of the UA-RA patients, 70% fulfilled the criteria within the first 6 months. UA-RA patients were older, more often positive for rheumatoid factor and anticitrullinated protein antibodies, female, and ever smokers, and they more often presented with polyarticular arthritis, small joint involvement, and a swollen shoulder joint. During followup, 53% of UA-RA patients vs 13% of UA-non-RA patients used DMARD (p < 0.001). Overall, 71% of patients with UA achieved absence of clinical synovitis at final followup without use of DMARD. The most frequent final clinical diagnosis was UA (61%). CONCLUSION: Only 9.8% of patients with UA fulfilled the 2010 RA criteria during 2-year followup. Small joint involvement and swollen shoulder joint were among the factors associated with RA development. In two-thirds of patients with UA, the arthritis resolved without use of DMARD.

Self-limiting arthritis among patients fulfilling the 2010 ACR/EULAR classification criteria for rheumatoid arthritis in a very early arthritis cohort.

OBJECTIVES: To study occurrence of and factors associated with self-limiting arthritis among patients fulfilling the 2010 ACR/EULAR classification criteria for rheumatoid arthritis (RA) (2010 RA criteria) in patients with ≤16 weeks׳ duration of joint swelling. METHODS: We applied the 2010 RA criteria in 1118 patients included in a 2-year longitudinal cohort. In all, 256 patients fulfilled the 2010 RA criteria at baseline; outcome was defined as either "self-limiting arthritis" (no DMARD use during follow-up, no swollen joints at last assessment, and no final clinical diagnosis of RA) or "persistent disease." The associations between baseline characteristics, including the components of the 2010 RA criteria score, and outcomes were studied. RESULTS: In total, 36 of 256 patients (14.1%) classified as having RA had self-limiting arthritis. These patients differed from patients with persistent disease according to ACPA positivity (11.1% vs. 65.0%, p < 0.001), duration of joint swelling (median = 47.5 vs. 66.0 days, p = 0.002), 2010 RA criteria points (median = 6.0 vs. 7.0, p < 0.001), and ever smoking (52.8% vs. 74.5%, p = 0.01). Having no serology points and no duration points were independent predictors of self-limiting arthritis. The rate of self-limiting arthritis was 2.7% vs. 29.4% among ACPA positive vs. ACPA negative patients (p < 0.001), and 32.5% when duration of joint swelling was <4 weeks vs. 10.6% with longer duration (p < 0.001). CONCLUSIONS: Negative ACPA status, short duration of joint swelling and being a never smoker were factors associated with self-limiting arthritis in early arthritis patients classified as having RA at presentation. Our findings contribute to identify patients who potentially do not need DMARDs and who should not be included in early RA clinical drug trials.

Patients' ratings of global perceived change during 2 years were strongly influenced by the current health status.

OBJECTIVES: To investigate the longitudinal validity of patients' ratings of global perceived change (GPC) and to assess the implications of using the GPC as the anchor to determine the minimal important change (MIC). STUDY DESIGN AND SETTING: Secondary analysis of data from a multicenter study including 380 patients with disc-related sciatica with follow-ups at 3, 6, 12, and 24 months. The GPC scale ranged from much worse to completely gone. Five patient-reported outcome measures were used. An MIC was defined as the mean change score in the actual outcome measure for patients reporting being better. The influence of patients' current state and baseline scores on the GPC was analyzed by multivariate linear regression. Differences in the magnitude of the MIC between the 3- and 24-month recall periods were analyzed by hierarchical linear models. RESULTS: Across all recall periods and outcome measures, the GPC was strongly influenced by the patient's state at the time of asking. In four of five outcome measures, the magnitude of the MIC increased when recall increased from 3 to 24 months. CONCLUSION: Caution is needed when using the GPC to determine the MIC of patient-reported outcome measures in patients with chronic conditions.

Prognostic factors for return to work in patients with sciatica.

BACKGROUND CONTEXT: Little is known about the prognostic factors for work-related outcomes of sciatica caused by disc herniation. PURPOSE: To identify the prognostic factors for return to work (RTW) during a 2-year follow-up among sciatica patients referred to secondary care. STUDY DESIGN/SETTING: Multicenter prospective cohort study including 466 patients. Administrative data from the National Sickness Benefit Register were accessed for 227 patients. PATIENT SAMPLE: Two samples were used. Sample A comprised patients who at the time of inclusion in the cohort reported being on partial sick leave or complete sick leave or were undergoing rehabilitation because of back pain/sciatica. Sample B comprised patients who, according to the sickness benefit register, at the time of inclusion received sickness benefits or rehabilitation allowances because of back pain/sciatica. OUTCOME MEASURES: In Sample A, the outcome was self-reported return to full-time work at the 2-year follow-up. In Sample B, the outcome was time to first sustained RTW, defined as the first period of more than 60 days without receiving benefits from the register. METHODS: Significant baseline predictors of self-reported RTW at 2 years (Analysis A) were identified by multivariate logistic regression. Significant predictors of time to sustained RTW (Analysis B) were identified by multivariate Cox proportional hazard modeling. Both analyses included adjustment for age and sex. To assess the effect of surgery on the probability of RTW, analyses similar to A and B were performed, including the variable surgery (yes/no). RESULTS: One-fourth of the patients were still out of work at the 2-year follow-up. In Sample A (n=237), younger age, better general health, lower baseline sciatica bothersomeness, less fear-avoidance work, and a negative straight-leg-raising test result were significantly associated with a higher probability of RTW at the 2-year follow-up. Surgery was not significantly associated with the outcome. In Sample B (n=125), history of sciatica, duration of the current sciatica episode more than 3 months, greater sciatica bothersomeness, fear-avoidance work, and back pain were significantly associated with a longer time to sustained RTW. Surgery was significantly negatively associated with time to sustained RTW both in univariate (hazard ratio [HR] 0.60; 95% confidence interval [CI] 0.39, 0.93; p=.02) and in multivariate (HR 0.49; 95% CI 0.31, 0.79; p=.003) analyses. CONCLUSIONS: The baseline factors associated with RTW identified in multivariate analysis were age, general health, history of sciatica, duration of the current episode, baseline sciatica bothersomeness, fear-avoidance work, back pain, and the straight-leg-raising test result. Surgical treatment was associated with slower RTW, but surgical patients were more severely affected than patients treated without surgery; so, this finding should be interpreted with caution.

Poor agreement found between self-report and a public registry on duration of sickness absence.

OBJECTIVE: To investigate the agreement between self-report and a public registry regarding the occurrence and duration of sickness absence (SA) in patients with sciatica. STUDY DESIGN AND SETTING: Observational 2-year longitudinal study including 227 patients. Self-report SA data were obtained by postal questionnaires covering recall periods of 3, 6, and 12 months and compared with data from the Norwegian National Sickness Benefit Register. RESULTS: The percent agreement on the occurrence of SA between self-report and registry was above 85% for all three recall periods. The patients overestimated the duration of their SA by 2.4 (95% confidence interval, 1.1-3.7) weeks for the 3-month recall period. The 95% limits of agreement were generally wide, varying from -12.5 to 17.3 weeks for the 3-month recall period to -38.8 to 37.2 weeks for the 12-month period. For the 3-, 6-, and 12-month recall periods, 48.1%, 29.8%, and 27.3% of the patients reported an SA duration that differed by ≤1 week from that recorded in the registry. CONCLUSION: Mainly because of low precision, the agreement on the duration of SA was poor for all three recall periods. The agreement between self-report and registry regarding the occurrence of SA was good.

Should anti-citrullinated protein antibody and rheumatoid factor status be reassessed during the first year of followup in recent-onset arthritis? A longitudinal study.

OBJECTIVE: Presence and levels of antibodies contribute to the classification of rheumatoid arthritis. We investigated the longitudinal course of anti-citrullinated protein antibodies (ACPA) and immunoglobin M (IgM) rheumatoid factor (RF) during the first year after arthritis onset in patients with very short disease duration. METHODS: Patients (aged 18-75 years) with ≥ 1 swollen joint of ≤ 16 weeks' duration had assessments of ACPA (2nd generation anti-cyclic citrullinated peptide antibodies, anti-CCP2) and IgM RF at inclusion and after 3, 6, and 12 months. Frequencies of seroconversions (negative to positive and vice versa) and changes in antibody levels during followup were determined. RESULTS: A total of 281 early arthritis patients (median duration of joint swelling 32 days, 14.2% ACPA positives, 12.8% IgM RF positives) with 978 longitudinally collected serum samples were included. Only 5 patients (1.8%) negative for both antibodies at baseline turned antibody-positive during followup, while 9 antibody-positive patients (3.2%) turned antibody-negative. ACPA was more stable than RF regarding both status and levels. CONCLUSION: Antibody status (ACPA/RF) is a stable phenotype in very early arthritis, as seroconversion was only found in 5% of patients. Repeated measurement of ACPA or RF during the first year after onset of arthritis does not offer major additional information.

Comorbid subjective health complaints in patients with sciatica: a prospective study including comparison with the general population.

OBJECTIVE: Chronic nonspecific low back pain is accompanied by high rates of comorbid mental and physical conditions. The aims of this study were to investigate if patients with specific back pain, that is, sciatica caused by lumbar herniation, report higher rates of subjective health complaints (SHCs) than the general population and if there is an association between change in sciatica symptoms and change in SHCs over a 12-month period. METHODS: A multicenter cohort study of 466 sciatica patients was conducted with follow-up at 3 months and 1 year. Comorbid SHCs were measured by 27 items of the SHC inventory. Odds ratios (ORs) for each SHC were calculated with comparison to a general population sample (n=928) by logistic regression. The SHC number was calculated by summing all complaints present. RESULTS: At baseline, the ORs for reporting SHCs for the sciatica patients were significantly elevated in 15 of the 27 items with a mean (S.D.) SHC number of 7.5 (4.4), compared to 5.2 (4.4) in the general population (P<.01). Among those who during the 1-year follow-up period fully recovered from their sciatica, the SHC number was reduced to normal levels. Among those with persisting or worsening sciatica, the number increased to a level almost double that of the general population. CONCLUSION: Compared to the general population, the prevalence of subjective health complaints in sciatica is increased. During follow-up, the number of health complaints increased in patients with persisting or worsening sciatica.

The likelihood of persistent arthritis increases with the level of anti-citrullinated peptide antibody and immunoglobulin M rheumatoid factor: a longitudinal study of 376 patients with very early undifferentiated arthritis.

INTRODUCTION: We wanted to assess the importance of the levels of anti-citrullinated peptide antibody (anti-CCP) and immunoglobulin M (IgM) rheumatoid factor (RF) in predicting development of persistent arthritis from undifferentiated arthritis (UA), and to investigate whether there is an added predictive value for persistent arthritis in testing for both anti-CCP and IgM RF. METHODS: Patients with UA (exclusion of definite non-rheumatoid arthritis (RA) diagnoses) included in the Norwegian very early arthritis clinic were assessed for development of persistent arthritic disease. The effect of antibody level on the likelihood of persistent arthritis was investigated, and the sensitivity and specificity for persistent arthritis for anti-CCP and IgM RF, separately and combined, was determined. RESULTS: A total of 376 UA patients were included (median arthritis duration 32 days). 59 (15.7%) patients were IgM RF positive, and 62 (16.5%) anti-CCP positive. One hundred, seventy-four (46.3%) had persistent disease after one year. Overlap of anti-CCP and IgM RF positivity was 58%. Sensitivity/specificity for persistent arthritis was 28/95% for IgM RF alone, 30/95% for anti-CCP alone, and 37/92% for positivity of both anti-CCP and IgM RF. The likelihood for persistent disease increased with increasing levels of both anti-CCP and IgM RF. CONCLUSIONS: The likelihood of developing persistent arthritis in UA patients increases with the level of anti-CCP and IgM RF. Testing both anti-CCP and IgM RF has added predictive value in UA patients. This study suggests that antibody level should be taken into account when making risk assessments in patients with UA.

Positive anti-citrullinated protein antibody status and small joint arthritis are consistent predictors of chronic disease in patients with very early arthritis: results from the NOR-VEAC cohort.

INTRODUCTION: The current 1987 American College of Rheumatology (ACR) classification criteria for rheumatoid arthritis (RA) have proven less useful in early arthritis. The objective of this study was to identify and compare predictors of three relevant outcomes of chronic arthritis in a cohort of very early arthritis patients. METHODS: The Norwegian Very Early Arthritis Cohort (NOR-VEAC) includes adult patients with at least one swollen joint of < or = 16 weeks' duration. Patients are followed for 2 years with comprehensive clinical and laboratory examinations. Logistic regression analyses were performed to determine independent predictors of three outcomes: persistent synovitis, prescription of disease-modifying anti-rheumatic drugs (DMARDs), and established clinical RA diagnosis within one year. RESULTS: Of 384 patients eligible for one year follow-up (56.3% females, mean (SD) age 45.8 (14.7) years, median (IQR) duration of arthritis 31 (10-62) days), 14.4% were anti-CCP2 positive, and 11.2% were IgM RF positive. 98 patients (25.5%) had persistent synovitis, 106 (27.6%) had received DMARD treatment during follow-up, while 68 (17.7%) were diagnosed with RA. Consistent independent predictors across all three outcomes were positive anti-citrullinated protein antibody (ACPA) status (odds ratio (OR) 3.2, 5.6 and 19.3), respectively, and small joint arthritis (proximal interphalangeal joint (PIP), metacarpo-phalangeal joint (MCP), and/or metatarso-phalangeal joint (MTP) joint swelling) (OR 1.9, 3.5, and 3.5, respectively). CONCLUSIONS: Positive ACPA status and small joint arthritis were consistent predictors of three relevant outcomes of chronic arthritis in very early arthritis patients. This consistency supports DMARD prescription as a valid surrogate endpoint for chronic arthritis. Importantly, this surrogate is used in ongoing efforts to develop new diagnostic criteria for early RA.