Long-Term Impact of Delay in Assessment of Patients With Early Arthritis

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1 ARTHRITIS & RHEUMATISM Vol. 62, No. 12, December 2010, pp DOI /art , American College of Rheumatology Long-Term Impact of Delay in Assessment of Patients With Early Arthritis Michael P. M. van der Linden, 1 Saskia le Cessie, 1 Karim Raza, 2 Diane van der Woude, 1 Rachel Knevel, 1 Tom W. J. Huizinga, 1 and Annette H. M. van der Helm-van Mil 1 Objective. During the last decade, rheumatologists have learned to initiate disease-modifying antirheumatic drugs (DMARDs) early to improve the outcome of rheumatoid arthritis (RA). However, the effect of delay in assessment by a rheumatologist on the outcome of RA has scarcely been explored. The purpose of this study was to examine the association between delay in assessment by a rheumatologist, rates of joint destruction, and probability of achieving DMARD-free remission in patients with RA. Patient characteristics associated with components of delay (by the patient, by the general practitioner [GP], and overall) were assessed. Methods. A total of 1,674 early arthritis patients from the Leiden Early Arthritis Clinic cohort were evaluated for patient delay, GP delay, and total delay in assessment by a rheumatologist. Among 598 RA patients, associations between total delay, achievement of sustained DMARD-free remission, and the rate of joint destruction over 6 years followup were determined. Results. The median patient, GP, and total delays in seeing a rheumatologist among patients with early arthritis were 2.4 weeks, 8.0 weeks, and 13.7 weeks, Supported by The Netherlands Organization for Health Research and Development, the Dutch Arthritis Association, and the European Union Seventh Framework Programme (integrated project Masterswitch and AutoCure). 1 Michael P. M. van der Linden, MD, MSc, Saskia le Cessie, PhD, Diane van der Woude, MD, Rachel Knevel, MD, Tom W. J. Huizinga, MD, PhD, Annette H. M. van der Helm-van Mil, MD, PhD: Leiden University Medical Center, Leiden, The Netherlands; 2 Karim Raza, PhD, FRCP: University of Birmingham, Birmingham, UK. Dr. Raza has received an honorarium for chairing a session and a consulting fee for a one-day advisory board session from Wyeth (less than $10,000). Dr. Huizinga has served as an expert witness in a patent dispute between Bayer and Abbott. Address correspondence and reprint requests to Michael P. M. van der Linden, MD, MSc, Department of Rheumatology, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, The Netherlands. M.P.M.van_der_Linden@lumc.nl. Submitted for publication April 1, 2010; accepted in revised form July 29, respectively. Among all diagnoses, those diagnosed as having RA or spondylarthritis had the longest total delay (18 weeks). Among the RA patients, 69% were assessed in >12 weeks; this was associated with a hazard ratio of 1.87 for not achieving DMARD-free remission and a 1.3 times higher rate of joint destruction over 6 years, as compared with assessment in <12 weeks. Older age, female sex, gradual symptom onset, involvement of the small joints, lower levels of C-reactive protein, and the presence of autoantibodies were associated with longer total delay. Conclusion. Only 31% of the RA patients were assessed in <12 weeks of symptom onset. Assessment in <12 weeks is associated with less joint destruction and a higher chance of achieving DMARD-free remission as compared with a longer delay in assessment. These results imply that attempts to diminish the delay in seeing a rheumatologist will improve disease outcome in patients with RA. Rheumatoid arthritis (RA) is a common chronic disease, affecting 1% of the population. It is associated with significant morbidity, mortality, and cost, both for the health service and for society. The disease is characterized by inflammation of the synovium, most frequently occurring in the small joints of the hands and feet; this inflammatory process frequently leads to loss of cartilage and to bone erosions. The level of joint destruction is correlated with the severity of inflammation (1,2). At present, potent disease-modifying antirheumatic drugs (DMARDs) and biologic agents are available to treat RA synovitis. It has been unequivocally demonstrated that early initiation of aggressive treatment schedules results in less joint damage and disability (3 6). This has led to the concept of the window of opportunity for treatment (7). Indeed, it has been demonstrated that initiation of treatment within

2 3538 VAN DER LINDEN ET AL weeks after disease onset results in lower levels of joint destruction (8) and increases the chance of achieving remission (9), which is increasingly regarded as the targeted outcome in therapeutic trials. Many studies have focused on the importance of diminishing the delay between the diagnosis of RA and the initiation of treatment. However, shortening the time period between the first symptoms and the first visit to a rheumatologist might be equally important. Thus far, the effect of delayed assessment by a rheumatologist on the outcome of the disease has scarcely been investigated. In the present study, we assessed the association between assessment delay and disease outcome in RA, as measured by the rate of joint destruction and the chance of achieving sustained DMARD-free remission. Second, we also aimed to determine the patient characteristics associated with longer delays by the patient in seeking medical care and delays by the general practitioner (GP) in referring the patient to a rheumatologist. Knowledge of these factors is of utmost importance. Rheumatologists nowadays are aware of the need to treat early. This implies that to further improve the outcome of RA, strategies should be established to ensure that delays in assessment are as brief as possible. Understanding the factors associated with delayed assessment is the first step required to achieving this goal. PATIENTS AND METHODS Patients. All patients were members of the Leiden Early Arthritis Clinic (EAC) cohort, a large inception cohort that enrolled all consecutive patients between 1993 and 2006 (10). This clinic is the only referral center in a health care region of 300,000 inhabitants. Patients were referred by their GPs when arthritis was suspected, and GPs were encouraged to refer to the EAC as soon as possible. Inclusion took place when synovitis was confirmed by physical examination and symptom duration was less than 2 years. At baseline, patients were asked about their joint symptoms, and they underwent a physical examination, which included a count of 66 joints for swelling and a count of 68 joints for tenderness (Ritchie Articular Index [11]). Blood samples were taken for routine diagnostic laboratory screening (including C-reactive protein [CRP] and IgM rheumatoid factor [IgM-RF]) and were stored for determination of other autoantibodies (e.g., anti cyclic citrullinated peptide 2 [anti CCP-2]) at a later time. Followup visits were performed on a yearly basis and included radiographs of the hands and feet (10). Written informed consent was obtained from all participants. This study was approved by the local Medical Ethics Committee. Of all 1,881 patients included in the EAC cohort, information on the dates of symptom onset was available for 1,674 of them. There were no significant differences between the baseline characteristics of the patients with and those without information about the symptom onset date, apart from slightly lower titers of acute-phase reactants in the group with missing data (data not shown). Among the 1,674 patients who had available information concerning the date of symptom onset, 598 patients (35.7%) were diagnosed as having RA according to the 1987 criteria of the American College of Rheumatology (formerly, the American Rheumatism Association) (12) within the first year of followup and had radiographs available. These patients were consecutively included between the years 1993 and Treatment strategies for RA changed over time and became more aggressive in subsequent inclusion periods ( , , and ) (10). Patients included before 1996 were treated initially with analgesics and subsequently with chloroquine or sulfasalazine if they had persistently active disease (delayed treatment). Between 1996 and 1998, RA patients were promptly treated with either chloroquine or sulfasalazine, and from 1999 onward, patients were promptly treated with either sulfasalazine or methotrexate. Determination of delay in assessment by a rheumatologist. Delay in the time to assessment by a rheumatologist was studied at 2 levels. Level 1 related to the delay between the onset of symptoms and a patient s being seen by his or her GP. This delay is a composite of the delay on the part of the patient in seeking an appointment with the GP and the time the patient has to wait to see the GP once he or she has contacted the GP for an appointment. In practice, the Dutch health care system is such that the second component of this is almost always very short. For simplicity, we have referred to level 1 delay as patient delay. Level 2 related to the delay between the patient s first assessment by his or her GP and the time when he or she was seen in the Leiden EAC. This delay is also a composite; in this case, it represents the time it takes a GP to decide to make a referral and the time it takes for the patient to see the rheumatologist once the referral has been made. The average wait for a patient to be seen in the Leiden EAC once a referral has been made is short ( 2 weeks). For simplicity, we have referred to level 2 delay as GP delay. The total delay was calculated as the sum of the patient delay and the GP delay. The duration of total delay was known for 1,674 of the early arthritis patients. Data on the first visit to a GP was available for 1,100 early arthritis patients. There were no significant differences between the characteristics of the patients with and those without information about the date of visiting the GP (data not shown). Analysis of associations between patient characteristics and delay were performed for patient delay, GP delay, and total delay. For all other analyses, the total delay was used. Since the literature indicates that the time period known as the window of opportunity is 12 weeks, the period of total delay was divided into 2 categories: 12 weeks and 12 weeks (7 9). Radiographic assessment. Radiographs of the hands and feet of the 598 RA patients were scored according to the Sharp/van der Heijde method (SHS) (13). Due to the study design (an inception cohort), not all patients had an equal duration of followup (median 4 years [interquartile range [IQR] 2 6]). Radiographic followup data were restricted to a maximum of 6 years because of an increasing frequency of missing radiographs later on. All radiographs were scored by an experienced scorer (MPMvdL) who was blinded with

3 IMPACT OF DELAY IN ASSESSMENT OF EARLY ARTHRITIS PATIENTS 3539 Table 1. Baseline characteristics of all early arthritis patients and the subset of early arthritis patients subsequently diagnosed as having RA* Characteristics Early arthritis patients (n 1,674) RA patients (n 598) No. (%) female 989 (59.1) 405 (67.7) Age at cohort inclusion, mean SD years Swollen joint count (of 66 joints), mean SD RAI (of 68 joints), mean SD No. (%) anti CCP-2 positive 391 (28.5) 309 (53.3) No. (%) IgM-RF positive 480 (29.2) 343 (58.0) CRP, mean SD mg/liter * Data on anti cyclic citrullinated peptide 2 (anti CCP-2) antibody status were available for 1,373 of the 1,674 early arthritis patients and for 580 of the 598 rheumatoid arthritis (RA) patients. Data on the IgM rheumatoid factor (IgM-RF) status were available for 1,645 of the 1,674 early arthritis patients and for 591 of the 598 RA patients. RAI Ritchie Articular Index; CRP C-reactive protein. respect to the clinical and treatment data. A total of 499 radiographs were rescored (149 baseline radiographs and 350 radiographs obtained during followup of 60 randomly selected RA patients). The intraclass correlation coefficient was 0.91 for all radiographs, 0.84 for baseline radiographs, and 0.97 for the radiographic progression rate. Assessment of sustained DMARD-free remission in patients with RA. Remission was defined in its most stringent form as the persistent absence of synovitis for at least 1 year after cessation of DMARD therapy and the identification of remission by the patient s rheumatologist (14). As such, this definition approaches cure of the disease. The remission status could be reliably ascertained in 557 of the 598 RA patients. Of these, 72 patients (12.9%) achieved sustained DMARD-free remission after a median followup of 3.33 years (IQR ). Most patients who achieved remission had a synovitisfree followup period that was longer than the minimum requirement of 1 year; the median time of observation after achieving sustained DMARD-free remission was 2.5 years. Statistical analysis. The duration of patient delay and GP delay in a given patient were compared using Wilcoxon s signed rank test. The association between delay and the rate of joint destruction during followup after the visit to a rheumatologist was assessed in the 598 RA patients using repeatedmeasures analysis on log-transformed radiologic data from subsequent yearly measurements. Log transformation was performed because of skewness of the radiologic data. The visit number and the delay group were entered as categorical variables. Adjustments were applied for age, sex, and EAC inclusion period (a proxy for treatment strategy) and their interaction with time, as described previously (15), since these factors are known to influence the rate of joint destruction. Differences in the rate of joint destruction between the delay groups were assessed by testing the interaction between time and delay group. The association between delay and disease progression was also analyzed with the onset of symptoms as a starting point. This was performed using a repeated-measures analysis with a random person and time effect, where the fixed effect of time was modeled with linear spline functions, with knots at each year. Analysis of sustained DMARD-free remission was performed by comparing Kaplan-Meier curves and by Cox regression analysis, taking into account the differences in followup times among patients. For patients who achieved remission, the dependent variable was time-to-event, indicating the time until remission was reached. For patients who did not achieve remission, the time to last followup was used. Again, two different starting points were considered: time from the onset of symptoms and time from the first visit to a rheumatologist. Cox regression for left-truncated data was used for the analysis with time from onset of symptoms to account for the fact that remission status was only observed after the first visit to a rheumatologist. Univariate analyses of baseline patient characteristics that were associated with delay in the early arthritis patients were performed using the Mann-Whitney U test and the Kruskal-Wallis test, since the delay data were not normally distributed. In order to identify baseline characteristics that independently associated with delay, variables that associated with delay on univariate analyses (P 0.05) were entered in a multivariate regression analysis with a backward selection method. For these analyses, delay data were log-transformed. To prevent exclusion of patients with missing data from the multivariate model, multiple imputations were performed (using SPSS software version 17.0). The complete set of data was used to generate 10 imputations that were subsequently applied to the multivariate analysis. SPSS software version 17.0 and R software (online at were used. P values less than 0.05 were considered significant. All reported P values are 2-sided. RESULTS Duration of delay in assessment by a rheumatologist. The baseline characteristics of all early arthritis patients and the subgroup of patients who were diagnosed as having RA are presented in Table 1. In all early arthritis patients, the median total delay was 13.7 weeks (IQR ), the GP delay was 8.0 weeks (IQR ), and the patient delay was 2.4 weeks (IQR ). The GP delay was significantly longer than the patient delay (median 8.0 weeks versus 2.4 weeks; P ). The median total delay in the subgroup of early arthritis patients who developed RA within the first year of followup was 18.4 weeks (IQR ). Also in this subgroup, the GP delay was

4 3540 VAN DER LINDEN ET AL significantly longer than the patient delay (median 11.8 weeks [IQR ] versus 3.3 weeks [IQR ]; P ). The applied treatment strategies for the RA patients differed for 3 inclusion periods; the median total delay for patients in these inclusion periods were 22.1 weeks for the years , 18.3 weeks for the years , and 18.3 weeks for the years (P 0.38). Among the entire subgroup of RA patients, only 186 (31.1%) were assessed within 12 weeks of symptom onset. Delay in assessment by a rheumatologist and outcome of RA. Within the group of 598 patients diagnosed as having RA, we investigated whether the degree of delay in assessment by a rheumatologist had an effect on the disease outcome, as measured by the progression in SHS over a 6-year period of followup and the achievement of sustained DMARD-free remission. The RA patients who saw a rheumatologist within 12 weeks of symptom onset had a lower rate of progression in the SHS (Figure 1A) than those with a delay of 12 weeks. Repeated-measures analysis comparing patient groups with delays of 12 weeks and 12 weeks showed that the difference in progression rate was statistically significant (P 0.001). Because of skewness of the data, the radiologic data were log-transformed before analy- Figure 1. Rate of joint destruction over 6 years of followup after the first assessment by a rheumatologist in rheumatoid arthritis (RA) patients with 12 weeks and 12 weeks of delay in the time to assessment. Because the radiologic data were not normally distributed, the median scores for the Sharp/van der Heijde assessment (SHS) are presented. A, SHS data for the entire group of 598 RA patients. B D, SHS data according to the different treatment strategies, which became more aggressive over time. The treatment strategies used were as follows: during , initial treatment with analgesics and subsequently with chloroquine or sulfasalazine if the patient had persistently active disease (delayed treatment) (B); during , prompt treatment with either chloroquine or sulfasalazine (C); and during , prompt treatment with either sulfasalazine or methotrexate (D). Figure 2. Probability of achieving sustained disease-modifying antirheumatic drug (DMARD) free remission in rheumatoid arthritis (RA) patients according to the different categories of delay in assessment by a rheumatologist. Remission was used as an outcome measure for the amount of total delay. Remission was defined as the persistent absence of synovitis for at least 1 year after the cessation of DMARD therapy and the identification of disease remission by the patient s rheumatologist (14). Total delay was calculated as the sum of the patient delay (time from symptom onset until being seen by the general practitioner [GP]) and the GP delay (time from assessment by the GP until being seen by the rheumatologist) (see Patients and Methods for details).

5 IMPACT OF DELAY IN ASSESSMENT OF EARLY ARTHRITIS PATIENTS 3541 Table 2. Baseline characteristics of early arthritis patients associated by univariate analysis with patient delay, GP delay, and total delay in assessment by a rheumatologist* Total delay (n 1,674) GP delay (n 1,111) Patient delay (n 1,078) Median (IQR) weeks P Median (IQR) weeks P Median (IQR) weeks P Sex Male 11.9 ( ) ( ) ( ) Female 15.3 ( ) 8.9 ( ) 2.9 ( ) Age at cohort inclusion, years ( ) ( ) ( ) ( ) 8.9 ( ) 2.6 ( ) Family history of RA No 13.6 ( ) ( ) ( ) Yes 14.9 ( ) 9.3 ( ) 2.9 ( ) Onset of symptoms Acute 5.6 ( ) ( ) ( ) Subacute 11.8 ( ) 7.7 ( ) 2.1 ( ) Gradual 26.0 ( ) 13.0 ( ) 5.9 ( ) Affected joints Small 16.9 ( ) ( ) ( ) Large 9.7 ( ) 4.4 ( ) 1.4 ( ) Both 13.1 ( ) 8.4 ( ) 2.0 ( ) Affected extremities Upper 15.1 ( ) ( ) ( ) Lower 8.6 ( ) 4.4 ( ) 1.3 ( ) Both 14.6 ( ) 8.4 ( ) 3.0 ( ) Symmetric distribution of affected joints Yes 14.6 ( ) ( ) ( ) No 12.6 ( ) 6.3 ( ) 2.0 ( ) Swollen joint count (of 66 joints) ( ) ( ) ( ) ( ) 11.1 ( ) 2.7 ( ) RAI (of 68 joints) ( ) ( ) ( ) ( ) 10.5 ( ) 3.6 ( ) Anti CCP-2 Positive 20.3 ( ) ( ) ( ) Negative 12.7 ( ) 6.7 ( ) 2.3 ( ) IgM-RF Positive 18.6 ( ) ( ) ( ) Negative 12.3 ( ) 6.3 ( ) 2.3 ( ) C-reactive protein, mg/liter ( ) ( ) ( ) ( ) 7.1 ( ) 2.0 ( ) * P values were determined by Mann-Whitney U test or Kruskal-Wallis test and reflect the difference within each delay group (total, general practitioner [GP], or patient delay); thus, the comparison made is, for example, whether the total delay is different between males and females. IQR interquartile range; RA rheumatoid arthritis; anti CCP-2 anti cyclic citrullinated peptide 2; IgM-RF IgM rheumatoid factor. The continuous variables age, C-reactive protein level, swollen joint count, and Ritchie Articular Index (RAI) were analyzed by creating 2 groups based on the median values. Defined durations of symptom onset were as follows: acute 24 hours, subacute 1 week, and gradual 1 week. sis; back-transforming the regression coefficient showed that over a period of 6 years after the first visit to the rheumatologist, patients with a delay of 12 weeks had a 1.34-fold higher rate of progression in the SHS than did patients with a delay of 12 weeks. In this analysis, adjustments were made for age, sex, and the 3 different EAC inclusion/treatment periods. Plotting the observed median radiologic scores over time for the different treatment periods separately (Figures 1B D) showed that RA patients assessed within 12 weeks of symptom onset had a lower progression rate, irrespective of the treatment period. Thus, although the increase in the aggressiveness of treatment after assessment by a rheumatologist reduced the overall level of the SHS, it did not diminish the effect of the delay in referral on the progression in the SHS.

6 3542 VAN DER LINDEN ET AL Table 3. Baseline characteristics of early arthritis patients associated by multivariate analysis with patient delay, GP delay, and total delay in assessment by a rheumatologist* Variable Hazard ratio (95% CI) P Total delay Age at cohort inclusion, years ( ) Female sex 1.12 ( ) Gradual onset 2.22 ( ) Involvement of small joints vs. large joints 1.31 ( ) Involvement of both small and large joints vs. large joints 1.16 ( ) Anti CCP ( ) IgM-RF 1.20 ( ) C-reactive protein ( ) GP delay Age at cohort inclusion, years ( ) Female sex 1.14 ( ) Gradual onset 1.93 ( ) Symmetric distribution of complaints 0.79 ( ) Anti CCP ( ) IgM-RF 1.22 ( ) C-reactive protein ( ) Patient delay Gradual onset 2.38 ( ) Involvement of joints of the lower extremities vs. upper extremities 0.73 ( ) Involvement of joints of both extremities vs. upper extremities 0.90 ( ) Anti CCP ( ) C-reactive protein ( ) * Linear regression analysis was performed on log-transformed data in each delay group (total, general practitioner [GP], or patient delay), and the regression coefficients were back-transformed for comprehensible results. The inverse log transformed coefficients present the estimated relative progression in delay. 95% CI 95% confidence interval; anti CCP-2 anti cyclic citrullinated peptide 2; IgM-RF IgM rheumatoid factor. For the continuous variables, a ratio of, for example, (age at inclusion) indicates a times longer delay when there is an increase in age of 1 year. For the categorical variables, a ratio of, for example, 1.31 (involvement of small joints versus large joints ) indicates a 1.31 times longer delay. The lower progression rate in the patients with a short delay ( 12 weeks) could have been due to the fact that these patients presented during an earlier phase of the disease course, with concomitantly less severe joint damage. To investigate whether this explained the observed difference, a second analysis of the progression in SHS was performed while taking into account the symptom duration before the first radiograph (i.e., before presentation). Thus, the followup time for all patients now began at the (self-reported) first date of symptoms. In this analysis, patients with a delay of 12 weeks had a significantly lower progression rate during the 6 years after the onset of the first symptoms as compared with patients with a delay of 12 weeks (P 0.001, adjusted for age, sex, and treatment period). Reports in the literature suggest that anti-ccp positive and anti-ccp negative RA represent 2 subsets of RA with differences in the underlying pathophysiologic mechanisms and disease course (16,17). To explore whether the effect of delay was different in anti-ccp positive and anti-ccp negative RA patients, stratified analyses were performed. Although stratification re- Figure 3. Total delay in assessment by a rheumatologist according to individual diagnoses in the 1,674 early arthritis patients at 1 year. Each data point represents a single patient; horizontal lines show the median. React reactive arthritis; Sarc sarcoidosis; Cryst crystal-induced arthritis; CTD connective tissue disease (including systemic lupus erythematosus and scleroderma); UA undifferentiated arthritis; OA inflammatory osteoarthritis; RA rheumatoid arthritis; SpA/PsA spondylarthritis/psoriatic arthritis.

7 IMPACT OF DELAY IN ASSESSMENT OF EARLY ARTHRITIS PATIENTS 3543 sulted in reduced power, a statistically significant association of a delay of 12 weeks with a lower progression in the SHS was observed in RA patients who were negative for anti CCP-2 (P for test for interaction without adjustment for age, sex, and treatment period and P for test for interaction adjusted for age, sex, and treatment period). In RA patients positive for anti CCP-2, a similar, though not significant, tendency was seen, with an observed lower rate of destruction in the group with 12 weeks delay (P for test for interaction 0.07 without adjustment for age, sex, and treatment period and P for test for interaction 0.18 adjusted for age, sex, and treatment period). Similar results were seen for achievement of sustained DMARD-free remission as were noted for the progression in the SHS. Sustained DMARD-free remission was achieved most frequently in RA patients who had a total delay of 12 weeks (Figure 2). In the group with 12 weeks delay, 18.5% of patients (31 of 168) achieved remission, and in the group with 12 weeks delay, 10.5% of patients (41 of 389) achieved remission. The hazard ratio (HR) for not achieving sustained DMARD-free remission was 1.87 (95% confidence interval [95% CI] ; P 0.008) for a total delay of 12 weeks as compared with 12 weeks. The difference did not change after adjusting for age, sex, and treatment period (HR 1.87 [95% CI ], P 0.009). Similar results comparing patients with a total delay of 12 weeks versus 12 weeks were obtained when the analysis was repeated with the date of the first symptoms as the starting point, both without (HR 1.90 [95% CI ]) and with (HR 1.90 [95% CI ]) correction for age, sex, and year of inclusion. Since only 8 patients in the anti CCP-2 antibody positive subset achieved DMARD-free remission, no stratified analysis was performed. Characteristics associated with delay in assessment by a rheumatologist. Patient characteristics associated with an increase in the delay in assessment by a rheumatologist were subsequently investigated in early arthritis patients (n 1,674). Univariate analysis showed that female sex, gradual symptom onset, older age at EAC inclusion, symmetric distribution of symptoms, involvement of the small joints, involvement of the joints of the upper extremities, the presence of IgM-RF and anti CCP-2 antibodies, and lower levels of CRP were all significantly associated with a longer duration of total delay (P 0.001) (Table 2). Multivariate regression analysis identified the following variables as being independently associated with a longer duration of total delay in assessment by a rheumatologist: older age, gradual symptom onset, involvement of small joints, presence of anti CCP-2 and IgM-RF, and lower CRP levels. As regression analysis was performed on log-transformed delay data, the relative estimated progressions were back-transformed to the original scale (Table 3). Patient characteristics associated with patient delay and GP delay showed comparable findings (Tables 2 and 3). The findings that the presence of autoantibodies (anti CCP-2 and IgM-RF), symmetric involvement of small joints, and a gradual onset of symptoms were associated with a longer delay, leads to the presumption that the delay in assessment by a rheumatologist differs for early arthritis patients with different diagnoses. To examine this, the patients with early arthritis were grouped according to the diagnoses that were achieved within the first year of followup, and the total delay durations were compared. This analysis showed that patients with reactive arthritis, sarcoidosis, and crystalinduced arthritis had the shortest delay in assessment (Figure 3). In contrast, patients with RA and those with spondylarthritis or psoriatic arthritis had the longest delay in assessment. DISCUSSION Initiation of treatment early in the disease course dramatically improves clinical outcomes in patients with RA. During the last decade, rheumatologists have developed a growing awareness of the need to treat early in the disease course, and this, together with the availability of newer therapies and improved predictive algorithms for patients with early arthritis (18,19), has improved the outcome of arthritis patients considerably (20). The findings of the present study show that RA patients who have a delay longer than 12 weeks between the first symptoms and an assessment by a rheumatologist have a worse disease outcome, as measured by the rate of joint destruction and by achievement of sustained DMARD-free remission. The effect of delay did not disappear when a more potent treatment strategy was applied after assessment by the rheumatologist. Importantly, among all early arthritis patients, those who were diagnosed as having RA had the longest delay in assessment by a rheumatologist, and the majority of RA patients were assessed after 12 weeks of symptoms, a period that has been referred to as the window of opportunity. These results suggest that to further improve the outcomes in RA patients, an important challenge is to get patients with arthritis to see a rheumatologist as early as possible after symptom onset.

8 3544 VAN DER LINDEN ET AL Diminishing the period of delay in assessment requires awareness on the part of both patients and their GPs. For this reason, the present study also evaluated the factors associated with the duration of the delay in assessment by a rheumatologist. This revealed that one of the important factors for early presentation to both the GP and the hospital was the acuteness of the onset of the symptoms. Patients with a gradual symptom onset had a longer delay than did patients with an acute or subacute onset of symptoms. Other patient characteristics associated with a longer delay were female sex and an older age at onset. A sex-specific delay in referral has been reported previously (21,22). Thus, to prevent a worse outcome of arthritis, our findings suggest that attention needs to be focused on educating patients, particularly older patients and female patients, about the significance of their symptoms and educating GPs on the necessity of rapidly referring patients, particularly older patients and female patients who have had a gradual onset of symptoms, to a rheumatologist. Several of the patient characteristics that were associated with the duration of delay in assessment of patients with early arthritis belong to clusters of variables that are characteristic of specific diagnoses. For example, an acute onset of symptoms and involvement of large joints of the lower extremities frequently occur in reactive arthritis or sarcoidosis; patients in these diagnostic groups had a short delay. In contrast, a gradual symptom onset and symmetric involvement of the small joints is more common in patients with RA. Both these characteristics and this diagnosis were associated with a longer delay in presentation and referral. Taken together, patients with chronic destructive diseases such as RA, but also psoriatic arthritis and spondylarthritis, who should be seen especially early by rheumatologists, had the longest delays in assessment. Therefore, the present results underline the importance of establishing strategies for tackling the reasons underlying the delay in assessment that have been identified at the patient and the GP levels (23,24). Although our findings provide insight into delay in assessment by a rheumatologist and its association with patient characteristics and disease outcome, the present study has several limitations. First, patients were included in the EAC only if they had a symptom duration of 2 years; patients who at first presentation had had symptoms for more than 2 years were not studied. However, patients with such a long delay are observed to be very infrequent in our outpatient clinic. Second, data were obtained from a single country. The largest contribution to the total delay in our study was the delay in referral by the GP. This is consistent with a study from the US (25) and is in contrast to recent findings in British cohorts, where the largest contribution to total delay was a delay on the part of the patient (26,27). Differences in health care systems as well as cultural differences (28) could account, at least partly, for the contrasting observations. Nevertheless, the median total delay for RA patients was well over 12 weeks in the UK, Canada, and The Netherlands (23 weeks [26], 17 weeks [29], and 18.4 weeks, respectively), and the present study highlights the consequences of that delay. The findings that RA patients with a longer delay had more severe joint destruction and less sustained DMARD-free remission are consistent with findings that early initiation of treatment is beneficial to the disease outcome (8,9). It was questioned whether the patients with a shorter delay truly had a better disease course or were just seen earlier in the disease course, resulting in a seemingly lower level of joint destruction. Our analyses were therefore repeated with the date of the first symptoms as the starting point. This showed that patients who had a delay of 12 weeks indeed developed less severe disease as compared with patients with a longer delay. There are 2 potential explanations for the observed difference in severity between the 12 weeks and 12 weeks delay groups. First, it may be that the RA patients who were assessed in a short time constitute a subset of RA that is itself characterized by a better outcome. It is known that the subset of RA characterized by the absence of anti-ccp antibodies has a better disease outcome than the anti-ccp positive subset (16), and in our data, anti CCP-2 positive patients more often had a gradual onset of symptoms (49.3% versus 38.2%) and a longer delay (median of 22.0 weeks versus 14.3 weeks) than did the anti CCP-2 negative RA patients. To account for such differences between RA patients, the effect of delay was studied in both the anti CCP-2 positive and anti CCP-2 negative subsets. This showed a significant association between delay in assessment and joint destruction in anti CCP-2 negative RA patients and a similar tendency in anti CCP-2 positive RA patients. The present data, however, have insufficient power for these subanalyses and, more specifically, do not allow us to draw definite conclusions about the effect of delayed assessment by a rheumatologist on joint destruction in the subset of anti CCP-2 positive patients. Second, patients assessed within 12 weeks of symptom onset were treated earlier in their disease course, which may have contributed to a less severe

9 IMPACT OF DELAY IN ASSESSMENT OF EARLY ARTHRITIS PATIENTS 3545 course of RA. This is consistent with previously reported data (4) and supports the hypothesized existence of a window of opportunity. Nonetheless, regardless of the explanation for our findings (better outcome in anti CCP-2 negative patients with a more acute symptom onset or better outcome due to early initiation of treatment) the main argument to refer for assessment by a rheumatologist as early as possible is that it provides the opportunity to modify RA during an early phase, with potential beneficial effects on the future disease course. In conclusion, a shorter time to assessment by a rheumatologist is associated with longer DMARD-free remission times and less joint destruction in RA. Despite this association, among all early arthritis patients, those diagnosed as having RA had one of the longest delays in assessment and only one-third of them were assessed within the so-called window of opportunity. Since rheumatologists are aware of the importance of treating early, our results suggest that in order to further improve disease outcomes in RA, it will be crucial to diminish the delay in assessment by a rheumatologist. Further studies could test whether accelerated treatment strategies indeed lead to improvement in disease outcomes in RA. ACKNOWLEDGMENT The authors thank Dr. A. J. M de Craen for critical comments on the manuscript. AUTHOR CONTRIBUTIONS All authors were involved in drafting the article or revising it critically for important intellectual content, and all authors approved the final version to be published. Dr. van der Linden had full access to all of the data in the study and takes responsibility for the integrity of the data and the accuracy of the data analysis. Study conception and design. Van der Linden, Raza, Huizinga, van der Helm-van Mil. Acquisition of data. Van der Linden, van der Woude, van der Helm-van Mil. Analysis and interpretation of data. 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