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Abstract

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

Objective

To compare the performance of different definitions of remission in a large multinational cross-sectional cohort of patients with rheumatoid arthritis (RA).

Methods

The Questionnaires in Standard Monitoring of Patients with RA (QUEST-RA) database, which (as of January 2008) included 5,848 patients receiving usual care at 67 sites in 24 countries, was used for this study. Patients were clinically assessed by rheumatologists and completed a 4-page self-report questionnaire. The database was analyzed according to the following definitions of remission: American College of Rheumatology (ACR) definition, Disease Activity Score in 28 joints (DAS28), Clinical Disease Activity Index (CDAI), clinical remission assessed using 42 and 28 joints (Clin42 and Clin28), patient self-report Routine Assessment of Patient Index Data 3 (RAPID3), and physician report of no disease activity (MD remission).

Results

The overall remission rate was lowest using the ACR definition of remission (8.6%), followed by the Clin42 (10.6%), Clin28 (12.6%), CDAI (13.8%), MD remission (14.2%), and RAPID3 (14.3%); the rate of remission was highest when remission was defined using the DAS28 (19.6%). The difference between the highest and lowest remission rates was ≥15% in 10 countries, 5–14% in 7 countries, and <5% in 7 countries (the latter of which had generally low remission rates [<5.5%]). Regardless of the definition of remission, male sex, higher education, shorter disease duration, smaller number of comorbidities, and regular exercise were statistically significantly associated with remission.

Conclusion

The use of different definitions of RA remission leads to different results with regard to remission rates, with considerable variation among countries and between sexes. Reported remission rates in clinical trials and clinical studies have to be interpreted in light of the definition of remission that has been used.

Although treatments for rheumatoid arthritis (RA) were formerly often called “remission-inducing drugs,” long-term remission (for >1 year) was seen in only a small minority of patients in usual clinical care (1). Remission rates in usual clinical care are now higher than in the past (2, 3), and the clinical status of RA patients who are treated actively in rheumatology clinics has improved substantially compared with previous decades (4–14).

Most randomized clinical trials are designed to analyze differences between active and control treatments, rather than to assess attainment of a specific clinical status such as remission. A few trials have focused on “tight control” of inflammation according to a protocol that guides treatment according to clinical responses. These trials have documented that in a large proportion of patients, remission can be achieved with methotrexate in combination with other traditional disease-modifying antirheumatic drugs (DMARDs) and with biologic agents.

In the FIN-RACo (Finnish Rheumatoid Arthritis Combination Therapy) trial (15), 2-year remission rates according to the Disease Activity Score in 28 joints (DAS28) (16) were 68% in the combination treatment arm and 41% in the monotherapy arm, and remission rates according to the American College of Rheumatology (ACR) definition (17) were 42% versus 20%, respectively, in the 2 groups. In the CIMESTRA (Cyclosporine, Methotrexate, Steroid in RA) trial (18), remission rates at 2 years in the combination treatment and monotherapy arms, respectively, were 59% and 54% for DAS28 remission and 41% and 35% for ACR remission. In the TICORA (Tight Control of RA) study (19), RA remission based on a DAS score of <1.6 was achieved in 65% of the patients in the “tight control” group and 16% in the control group. In the BeSt (Behandelstrategieën voor Reumatoide Artritis [Treatment Strategies for RA]) study (20), RA was in remission in 38–46% of patients in the 4 treatment arms at the end of intervention. Thus, it appears that “tight control” is a “remission-inducing” strategy in patients with early RA.

There is no single “gold standard” measure for RA disease activity. Accordingly, disease activity or its absence (remission) is measured using various composite indices such as the ACR core data set (21), the DAS, and others. Rates of remission differ according to these indices, and different levels have been described to depict “true” remission (22, 23).

In the present study, we compared the performance of different definitions of remission in 5,848 patients from 24 countries who are included in the Questionnaires in Standard Monitoring of Patients with RA (QUEST-RA) database (24). We analyzed remission rates by country and investigated possible associations between demographic and lifestyle variables and remission.

PATIENTS AND METHODS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

The QUEST-RA program was established in 2005 to promote quantitative assessment in usual clinical care at multiple sites, and to develop a database of RA patients seen in regular care in many countries. The initial design involved assessment of 100 RA patients at ≥3 sites in different countries. Data collection was begun in January 2005. By January 2008, the program included 5,848 patients from 67 sites in 24 countries (Argentina, Canada, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Kosovo, Latvia, Lithuania, The Netherlands, Poland, Russia, Serbia, Spain, Sweden, Turkey, the United Arab Emirates, the United Kingdom, and the United States) (24). These 5,848 patients comprised the present study population. All patients were assessed according to a standard protocol to evaluate RA (25).

Clinical evaluation.

Physicians completed three 1-page forms on each patient: 1) a review of clinical features, including classification criteria, extraarticular features, comorbidities, and relevant surgeries; 2) information on all previous and present DMARDs taken, their adverse events, and reasons for discontinuation; and 3) results of a 42-joint count (26) which included a swollen joint count (SJC) and tender joint count (TJC), as well as a count of joints with limited motion or deformity. The review included physician global assessment of disease activity (MDglobal) on a 10-cm visual analog scale (VAS) in which the physician was asked “Please mark below your assessment of the patient's current disease activity,” with “no activity” at the left end and “very active” at the right end. The review also included the physician's report of whether the patient had radiographic erosions, and findings of laboratory tests, i.e., erythrocyte sedimentation rate (ESR), C-reactive protein level, and rheumatoid factor status.

Patient questionnaires.

Patients completed a 4-page expanded self-report questionnaire that included the Health Assessment Questionnaire (HAQ) (27) and the multidimensional HAQ (28) to assess functional capacity in activities of daily living. Pain, patient-rated global health status (GH), fatigue, and patient-report current disease activity (PTglobal) (29) were assessed on a 0–10–cm VAS. Information on duration of morning stiffness, lifestyle choices such as smoking and physical exercise, height and weight for calculation of body mass index (BMI), and demographic characteristics including years of education and work status was collected (24).

Definitions of remission.

The database was analyzed for remission according to the following definitions.

1. ACR remission: 5 of 6 criteria met, including (a) no swollen joints on 42-joint count, (b) no tender joints on 42-joint count, (c) normal ESR (<30 mm/hour in women and <20 mm/hour in men), (d) morning stiffness ≤15 minutes, (e) no joint pain (≤1.0 cm on VAS), and (f) no fatigue (≤1.0 cm on VAS) (17).

2. DAS28 remission: DAS28 score of <2.6, calculated using the formula

  • equation image

(16, 30).

3. Clinical Disease Activity Index (CDAI) remission: CDAI score of ≤2.8, from the formula SJC28 + TJC28 + PTglobal + MDglobal (31).

4. Clinical remission (Clin28 and Clin42): 3 of 3 criteria for Clin28 met, including (a) no swollen joints on 28-joint count, (b) no tender joints on 28-joint count, and (c) normal ESR (<30 mm/hour in women and <20 mm/hour in men); or 3 of 3 criteria for Clin42 met, including (a) no swollen joints on 42-joint count, (b) no tender joints on 42-joint count, and (c) normal ESR (<30 mm/hour in women and <20 mm/hour in men).

5. Routine Assessment of Patient Index Data 3 (RAPID3) remission: score of ≤1.0 on the RAPID3, an index that is based on patient self-report outcomes only and includes HAQ physical function, pain, and GH, all normalized to 0–10, counted together, and divided by 3 to yield a scale of 0–10 (32).

6. MD remission: no disease activity according to the rheumatologist (MDglobal ≤0.3) (33) (3 mm was allowed for “writing” error in MD/assistant handwriting).

Statistical analysis.

Remission rates are presented as percentages with 95% confidence intervals (95% CIs). The unadjusted prevalence of remission according to different definitions is presented for each country. The prevalence of ACR and DAS28 remission adjusted for sex, age, and disease duration is also shown by country. Remission rates based on different definitions were also calculated for females and males according to SJC28, in arbitrary categories of 0, 1, 2–3, and ≥4 swollen joints, and differences assessed by chi-square test.

Kappa and Jaccard statistics (with 95% CIs) were used to assess agreement between different remission criteria and to study the agreement between the Clin28 and other remission criteria. These two methods for assessing agreement were used because kappa “total” agreement takes into account all observations (positive and negative) (a = +,+; b = −,+; c = +,−; d = −,−), whereas in the Jaccard method, positive agreement is divided by all positive observations (a/[a + b + c]). Therefore, the Jaccard statistic represents the probability of both positive observations occurring together.

To study the association of remission with demographic and lifestyle-related variables, forward stepwise logistic regression models were applied separately for each definition of remission. The model included sex, age, disease duration, number of comorbidities, BMI (<30 mg/kg2 versus ≥30 mg/kg2), current smoking status (no/yes), and frequency of physical exercise (regular exercise 1 or more times a week versus no regular exercise). The model also included level of education. Because of different school systems in different countries, the highest tertile of years of education in each country was defined as “higher education” (versus “lower education,” which represented the lowest two-thirds of years of education in each country).

RESULTS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

Demographic and clinical characteristics of the study patients.

As of January 2008 the QUEST-RA database included 5,848 patients from 67 sites in 24 countries. The demographic characteristics were those of a typical RA cohort: 79% of the patients were female, >90% were white, the mean age was 57 years, and the mean education level was 11 years (with considerable variation between countries) (24). Data were missing for <5% of variables, and various remission criteria could be calculated for >95% of the patients.

Comparison of definitions of remission.

Different definitions yielded statistically significantly different remission rates, as illustrated in Figure 1. The remission rates calculated using the various definitions were as follows: 8.6% for ACR remission, 10.6% for Clin42, 12.6% for Clin28, 13.8% for CDAI, 14.2% for MD remission, 14.3% for RAPID3, and 19.6% for DAS28 remission (Figure 1 and Table 1). Overall agreement was moderate (κ = 0.55 [95% CI 0.53–0.57]).

thumbnail image

Figure 1. Unadjusted rates of remission in the QUEST-RA (Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis) study, according to different definitions. Bars show the 95% confidence intervals. ACR = American College of Rheumatology definition of remission; Clin42 and Clin28 = clinical remission assessed using 42 and 28 joints; CDAI = Clinical Disease Activity Index definition of remission; MD = physician report of no disease activity; RAPID3 = remission according to the patient self-report Routine Assessment of Patient Index Data 3; DAS28 = remission according to the Disease Activity Score in 28 joints. See Patients and Methods for details on each definition of remission.

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Table 1. Unadjusted rates of remission according to different definitions in the QUEST-RA study, by country*
CountryDefinition of remissionDifference between lowest and highest
ACRClin42Clin28CDAIMD remissionRAPID3DAS28
  • *

    Values are the percent of patients. QUEST-RA = Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis; ACR = American College of Rheumatology; Clin42 and Clin28 = clinical remission assessed using 42 and 28 joints; CDAI = Clinical Disease Activity Index; MD remission = physician report of no disease activity; RAPID3 = patient self-report Routine Assessment of Patient Index Data 3; DAS28 = Disease Activity Score in 28 joints. See Patients and Methods for details on each definition of remission.

Greece21.525.927.435.325.135.036.515.0
The Netherlands16.325.930.430.638.522.740.824.5
Spain14.216.719.920.121.719.329.715.5
Ireland14.013.415.121.321.922.122.49.0
US13.817.818.718.514.825.936.122.3
Denmark12.315.217.422.223.223.830.918.5
Finland12.314.020.523.825.322.036.624.3
France11.713.217.914.213.317.229.217.5
Sweden9.715.918.319.019.115.424.414.7
UAE9.29.710.911.614.525.218.816.0
UK8.38.59.313.220.711.718.412.4
Italy8.210.211.510.410.23.07.78.5
Canada8.010.112.117.024.013.019.816.0
Turkey7.910.712.313.38.010.014.46.5
Germany5.910.511.29.812.310.718.112.2
Argentina3.72.02.94.55.59.38.47.3
Estonia3.61.85.44.83.07.19.27.4
Russia2.81.41.41.41.44.24.53.1
Latvia2.51.33.83.81.33.85.54.2
Poland1.11.31.72.02.75.53.54.4
Hungary0.70.00.01.33.93.32.63.9
Lithuania0.30.00.30.33.32.01.43.3
Serbia0.00.01.00.00.00.00.01.0
Kosovo0.01.01.00.00.02.01.02.0
Total8.610.612.613.814.214.319.611.0

Remission according to different definitions, by country.

In the 24 countries, the prevalence of remission ranged between 0 and 22% by the ACR definition, 0 and 26% by the Clin42 definition, 0 and 30% by the Clin28 definition, 0 and 35% by the CDAI definition, 0 and 39% by the MD remission definition, 0 and 35% by the RAPID3 definition, and 0 and 41% by the DAS28 definition (Table 1). The difference between the highest remission rate and the lowest remission rate was ≥15% in 10 countries, 5–14% in 7 countries, and <5% in 7 countries (with low remission rates [<5.5%] according to all definitions in the latter group of countries) (Table 1). Sex-, age-, and disease duration–adjusted remission rates in each country according to the ACR and DAS28 definitions are illustrated in Figure 2.

thumbnail image

Figure 2. Sex-, age, and disease duration–adjusted rates of remission by country in the QUEST-RA (Questionnaires in Standard Monitoring of Patients with Rheumatoid Arthritis) study, according to the ACR and DAS28 definitions of remission. Bars show the 95% confidence intervals. See Figure 1 for definitions.

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Clin28 remission.

Other definitions of remission were compared with Clin28 remission. Agreement percentage and specificity between other definitions and the Clin28 definition were excellent (Table 2). Sensitivity was high for DAS28, CDAI, and Clin42 remission, but roughly half of those who met Clin28 remission also met ACR, RAPID3, and MD remission (Table 2). Agreement between Clin28 and other definitions according to the Jaccard and kappa statistics was low to moderate, except for excellent agreement with Clin42 (which is the extension of Clin28) (Table 2).

Table 2. Comparison of other definitions of remission with clinical remission defined using the 28-joint count*
Definition of remissionObserver agreement, %Sensitivity, %Specificity, %Jaccard statisticKappa statistic
  • *

    Values in parentheses are 95% confidence intervals. See Table 1 for definitions; see Patients and Methods for details on each definition of remission.

ACR91 (90–92)49 (47–51)97 (96–99)0.42 (0.39–0.46)0.54 (0.50–0.57)
Clin4297 (96–98)84 (82–85)100 (98–100)0.84 (0.81–0.87)0.90 (0.88–0.92)
CDAI92 (91–93)70 (68–72)95 (94–96)0.52 (0.49–0.55)0.63 (0.60–0.67)
MD remission89 (88–90)59 (55–63)93 (91–94)0.40 (0.37–0.43)0.50 (0.47–0.54)
RAPID385 (83–87)46 (43–48)90 (88–92)0.28 (0.25–0.31)0.34 (0.32–0.39)
DAS2891 (90–92)88 (87–89)91 (89–92)0.56 (0.52–0.59)0.66 (0.64–0.68)

Remission and demographic and lifestyle variables.

Regardless of the definition of remission, male sex, higher education, shorter disease duration, lower number of comorbidities, and regular exercise were statistically significantly associated with remission (Table 3). Older age was associated with Clin28, CDAI, and MD remission. BMI and current smoking status were not associated with remission in a multivariate model.

Table 3. Forward stepwise logistic regression models for remission according to different definitions*
VariableDefinition of remission
ACRClin42Clin28CDAIMD remissionRAPID3DAS28
  • *

    Only variables that remained in the final model are shown. Values are the odds ratio (95% confidence interval). See Table 1 for definitions; see Patients and Methods for details on each definition of remission.

Female sex0.56 (0.44–0.70)0.65 (0.53–0.81)0.68 (0.56–0.84)0.55 (0.46–0.67)0.56 (0.47–0.68)0.53 (0.44–0.64)0.47 (0.39–0.55)
Age  1.01 (1.00–1.02)1.01 (1.00–1.01)1.01 (1.00–1.01)  
Disease duration0.98 (0.97–0.99)0.98 (0.97–0.99)0.99 (0.98–1.00)0.98 (0.97–0.99)0.97 (0.96–0.98)0.97 (0.96–0.98)0.98 (0.97–0.99)
High education1.28 (1.04–1.58) 1.28 (1.06–1.53)1.45 (1.21–1.73)1.23 (1.03–1.47)1.50 (1.27–1.79)1.30 (1.11–1.52)
No. of comorbidities0.71 (0.63–0.81)0.76 (0.68–0.85)0.72 (0.65–0.80)0.75 (0.68–0.83)0.84 (0.76–0.92)0.73 (0.67–0.81)0.76 (0.70–0.82)
Regular exercise1.80 (1.46–2.22)1.60 (1.32–1.94)1.67 (1.39–2.00)1.71 (1.44–2.03)1.81 (1.52–2.16)2.21 (1.86–2.62)2.05 (1.75–2.39)

Remission and sex.

Rates of remission, regardless of definition, were higher among men than among women (Table 4). Among patients who had no swollen joints, remission rates in women versus men were 21% versus 30% (ACR), 32% versus 38% (Clin42), 38% versus 44% (Clin28), 37% versus 51%, (CDAI), 33% versus 46% (MD remission), 25% versus 35% (RAPID3), and 42% versus 58% (DAS28). Among patients who had 1 swollen joint, men had significantly higher remission rates according to ACR, DAS28, and RAPID3, but not CDAI remission (Table 4).

Table 4. Unadjusted rates of remission in female and male patients in the QUEST-RA study, by number of swollen joints*
No. of swollen jointsDefinition of remission
ACRClin42Clin28CDAIMD remissionRAPID3DAS28
  • *

    Values are the percent of patients. See Table 1 for definitions; see Patients and Methods for details on each definition of remission.

Any       
 All8.610.612.613.814.214.319.6
 Female7.69.912.112.812.712.317.1
 Male13.214.917.221.921.721.330.6
 P<0.001<0.001<0.001<0.001<0.001<0.001<0.001
0       
 All23.433.239.840.036.127.146.1
 Female21.431.538.436.532.924.542.1
 Male29.538.244.050.745.634.757.5
 P<0.0010.010.036<0.001<0.001<0.001<0.001
1       
 All2.7009.713.116.419.7
 Female1.4008.811.513.216.9
 Male7.50012.918.628.029.6
 P<0.001  0.120.046<0.0010.003
2–3       
 All2.5001.54.311.29.9
 Female2.2001.23.99.27.4
 Male3.4002.45.819.119.5
 P0.36  0.220.290.001<0.001
≥4       
 All0.80001.04.42.3
 Female0.80000.84.21.8
 Male0.80001.85.44.4
 P0.86   0.0890.270.003

DISCUSSION

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

The results of this study show that the use of different definitions of remission results in different reported remission rates. ACR remission is the most stringent. It includes signs and symptoms that are prevalent in an older population; we have reported previously that 85% of a community population age >50 years did not meet the ACR criteria for remission of RA (34). The DAS28 provides the most liberal definition, i.e., the highest remission rates, and is possibly therefore preferred in clinical trials (22), but with this definition, groups classified as having disease that is in remission may include patients with considerable residual disease activity (Table 4). A lower cut point for definition of DAS28 remission, i.e., 2.32 rather than 2.6, has been suggested (35). In the current patient population this cut point yielded a remission rate of 14.3%, similar to the rates obtained with the Clin28, CDAI, RAPID3, and MD remission definitions.

The QUEST-RA study provides an opportunity to compare different definitions of remission within and between many countries with significant variation in disease activity and remission rates. This opportunity has not been available until recently (24), since most reported data on RA are based on clinical trials of specific clinical cohorts, with data stored in separate databases. The QUEST-RA data from 24 countries indicate that remission rates differ notably between countries, a phenomenon that requires further analysis, probably including exploration of factors beyond biomedical ones. Nevertheless, the availability of data from many countries from the QUEST-RA emphasizes the generalizability of the observation that remission rates vary considerably with the use of different definitions of remission, except in countries in which only a very small proportion of patients have disease that is in remission.

Some recent reports indicate that male sex is a major predictor of remission in early RA (36, 37) and that male patients respond better than female patients to treatments with biologic agents (38–40). In the QUEST-RA database, RA was more likely to be in remission, according to all definitions, among men. Among patients who had no swollen joints, higher remission rates were seen in men than in women (Table 4), indicating that among these patients the lower remission rates in women are accounted for by other components of the indices, such as number of tender joints, patient self-report scores, and higher normal ESR in women (41). Higher remission rates in men might reflect, at least in part, sex differences in the measures themselves, rather than true sex differences in RA disease activity.

In addition to male sex, shorter disease duration, higher education level, smaller number of comorbidities, and regular physical exercise were associated with remission in a multivariate model. BMI and current smoking status were not associated with remission in this model.

Based on a traditional rheumatology (biomedical) model, patients whose RA is in remission would not have any signs of inflammation on careful clinical examination (42–44), and we therefore included MD remission, Clin42, and Clin28 in this study. However, examination of remission rates in different countries (Table 1) provides somewhat confusing observations which suggest that the biomedical model for remission may not be useful in usual clinical practice.

Paulus (23) suggested that although remission cannot be fully defined, a rheumatologist identifies it easily on clinical examination. However, the proportion of patients with MD remission, relative to remission according to other definitions, ranged widely among countries (Table 1), suggesting that physicians in some countries are more liberal than in others and that MD remission can not be used as a gold standard for remission.

The Clin42 definition of remission (no tender joints and no swollen joints, including ankles and feet) was included in the present study on the basis of criticism, by us and others, of the exclusion of ankles and feet from measures of disease activity (45). However, excluding the countries with very low overall rates of remission, remission rates according to the Clin28 and the Clin42 were very similar to one another in all countries except in one, where the Clin42 remission rate was 32% lower than the Clin28 remission rate (Table 1). This may be explained by a large local emphasis on the role of feet in RA (46, 47), including careful clinical examination. However, it has been shown in earlier studies (48) and more recently (49) that a full (66- or 68-) joint count is not needed for valid assessment of RA in groups of patients.

We regarded the Clin28 as a definition that might provide the best reflection of remission according to a biomedical model, and we compared other definitions with it. However, this assumption is called into question by the recent observation that among 107 patients with RA who were judged by the treating rheumatologists to be in clinical remission, almost 50% had progression exhibited on hand/wrist magnetic resonance imaging over 12 months (50). An “objective” clinical examination thus appears not accurate enough to assess true remission in RA.

It is an intriguing idea to use only patient-report data to determine remission, since these data are easy to collect in usual care. Overall, the RAPID3 appears to perform quite similarly to other definitions, with virtually identical prevalence of remission as that obtained with the CDAI and MD remission definitions. Among patients with no swollen joints, the RAPID3 classifies RA as being in remission in the second-fewest patients (second to ACR remission), but performs similarly to the DAS28 among patients who have residual swollen joints (Table 4). The inclusion of ∼10% of patients with 2–3 swollen joints as being in remission according to the DAS28 or RAPID3 definition is a disadvantage, and lower cut points for remission might be considered. Because high patient-report scores of function, pain, and global status are more prevalent in elderly populations (34), it might be possible to include a patient self-report joint count in a definition of remission, possibly excluding joints with common symptoms of osteoarthritis such as knees and fingers.

A large international multicenter database such as the QUEST-RA may provide advantages over other databases for studying different definitions of remission and searching for definitions that could be applied in usual clinical settings. One of the strengths of this collaboration is that it includes patients with adult-onset RA, with no additional inclusion and exclusion criteria. Therefore, the patients represent a large range of clinical activity, from mild to severe (24). Furthermore, rheumatologists who provided data were working in real-life settings with no major benefits to collecting data except their own interest in contributing to the rheumatology community. Data were collected in different clinical environments; traditional ways of examining and treating patients reflect reality and may greatly vary in the participating countries, which is also a limitation of the study.

In conclusion, the use of different definitions of remission yields different remission rates. Reports concerning remission should include a rationale for the choice of definition of remission, and results should be interpreted accordingly. Furthermore, all currently used remission definitions appear to favor men. Therefore, the rheumatology community is obliged to continue to search for an optimal definition of remission.

AUTHOR CONTRIBUTIONS

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

Dr. Sokka 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 design. Sokka, Hetland, Mäkinen, Kautianen, Pincus.

Acquisition of data. Sokka, Hetland, Mäkinen, Kautiainen, Hørslev-Petersen, Luukkainen, Combe, Badsha, Drosos, Devlin, Ferraccioli, Morelli, Hoekstra, Majdan, Sadkiewicz, Belmonte, Holmqvist, Choy, Burmester, Tunc, Dimić, Nedović, Stanković, Bergman, Toloza, Pincus.

Analysis and interpretation of data. Sokka, Hetland, Mäkinen, Kautiainen, Pincus.

Manuscript preparation. Sokka, Hetland, Mäkinen, Kautiainen, Luukkainen, Drosos, Toloza, Pincus.

Statistical analysis. Sokka, Kautiainen.

ROLE OF THE STUDY SPONSOR

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

Abbott did not have a role in the study design, data collection, data analysis, writing of the manuscript, review of the manuscript, or decision to submit the manuscript for publication.

REFERENCES

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A
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  • 3
    Listing J, Strangfeld A, Rau R, Kekow J, Gromnica-Ihle E, Klopsch T, et al. Clinical and functional remission: even though biologics are superior to conventional DMARDs overall success rates remain low—results from RABBIT, the German biologics register. Arthritis Res Ther 2006; 8: R6675.
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ADDENDIX A

  1. Top of page
  2. Abstract
  3. PATIENTS AND METHODS
  4. RESULTS
  5. DISCUSSION
  6. AUTHOR CONTRIBUTIONS
  7. ROLE OF THE STUDY SPONSOR
  8. REFERENCES
  9. ADDENDIX A

THE QUEST-RA GROUP

Members of the QUEST-RA Group, in addition to the authors, were as follows: Santiago Aguero, Sergio Orellana Barrera, Soledad Retamozo (Hospital San Juan Bautista, Catamarca, Argentina), Paula Alba, Eduardo Albiero, Alejandra Babini, Cruz Lascano (Hospital of Cordoba, Cordoba, Argentina), Juris Lazovskis (Riverside Professional Center, Sydney, Nova Scotia, Canada), Lykke Ørnbjerg (Copenhagen University Hospital at Hvidovre, Hvidovre, Denmark), Troels Mørk Hansen, Lene Surland Knudsen (Copenhagen University Hospital at Herlev, Herlev, Denmark), Riina Kallikorm, Reet Kuuse, Raili Müller, Marika Tammaru (Tartu University Hospital, Tartu, Estonia), Tony Peets (East Tallinn Central Hospital, Tallinn, Estonia), Ivo Valter (Center for Clinical and Basic Research, Tallinn, Estonia), Sinikka Forsberg, Kai Immonen, Jukka Lähteenmäki (North Karelia Central Hospital, Joensuu, Finland), Maxime Dougados, Laure Gossec (University René Descartes, Hôpital Cochin, Paris, France), Jean Francis Maillefert (Dijon University Hospital, University of Burgundy, Dijon, France), Jean Sibilia (Hôpital Hautepierre, Strasbourg, France), Gertraud Herborn, Rolf Rau (Evangelisches Fachkrankenhaus, Ratingen, Germany), Rieke Alten, Christof Pohl (Schlosspark-Klinik, Berlin, Germany), Sofia Exarchou (University of Ioannina, Ioannina, Greece), H. M. Moutsopoulos, Afrodite Tsirogianni (National University of Athens, Athens, Greece), Maria Mavrommati, Fotini N. Skopouli (Euroclinic Hospital, Athens, Greece), Pál Géher (Semmelweis University of Medical Sciences, Budapest, Hungary), Bernadette Rojkovich, Ilona Újfalussy (Polyclinic of the Hospitaller Brothers of St. John of God in Budapest, Budapest, Hungary), Barry Bresnihan (St. Vincent University Hospital, Dublin, Ireland), Patricia Minnock (Our Lady's Hospice, Dublin, Ireland), Eithne Murphy, Edel Quirke, Claire Sheehy (Connolly Hospital, Dublin, Ireland), Shafeeq Alraqi (Waterford Regional Hospital, Waterford, Ireland), Stefano Bombardieri, Massimiliano Cazzato (Santa Chiara Hospital, Pisa, Italy), Maurizio Cutolo (University of Genoa, Genoa, Italy), Fausto Salaffi, Andrea Stancati (University of Ancona, Ancona, Italy), Sylejman Rexhepi, Mjellma Rexhepi (Pristine, Kosovo), Daina Andersone (Pauls Stradina Clinical University Hospital, Riga, Latvia), Jolanta Dadoniene, Sigita Stropuviene (Vilnius University, Vilnius, Lithuania), Asta Baranauskaite (Kaunas University Hospital, Kaunas, Lithuania), Johannes W. G. Jacobs, Suzan M. M. Verstappen (University Medical Center Utrecht, Utrecht, The Netherlands), Margriet Huisman (Sint Franciscus Gasthuis Hospital, Rotterdam, The Netherlands), Stanislaw Sierakowski (Medical University in Bialystok, Bialystok, Poland), Wojciech Romanowski (Poznan Rheumatology Center in Srem, Srem, Poland), Witold Tlustochowicz (Military Institute of Medicine, Warsaw, Poland), Danuta Kapolka (Silesian Hospital for Rheumatology and Rehabilitation in Ustron Slaski, Ustron Slaski, Poland), Danuta Zarowny-Wierzbinska (Wojewodzki Zespol Reumatologiczny im. dr Jadwigi Titz-Kosko, Sopot, Poland), Dmitry Karateev, Elena Luchikhina (Institute of Rheumatology of the Russian Academy of Medical Sciences, Moscow, Russia), Natalia Chichasova (Moscow Medical Academy, Moscow, Russia), Vladimir Badokin (Russian Medical Academy of Postgraduate Education, Moscow, Russia), Vlado Skakic (Rheumatology Institut, Niska Banja, Serbia), Antonio Naranjo, Carlos Rodríguez-Lozano (Hospital de Gran Canaria Dr. Negrin, Las Palmas, Spain), Jaime Calvo-Alen (Hospital Sierrallana Ganzo, Torrelavega, Spain), Eva Baecklund, Dan Henrohn (Uppsala University Hospital, Uppsala, Sweden), Margareth Liveborn, Rolf Oding (Centrallasarettet, Västerås, Sweden), Feride Gogus (Gazi Medical School, Ankara, Turkey), Selda Celic (Cerrahpasa Medical Faculty, Istanbul, Turkey), Ayman Mofti (American Hospital Dubai, Dubai, United Arab Emirates), Catherine McClinton, Peter Taylor (Charing Cross Hospital, London, UK), Ginny Chorghade, Anthony Woolf (Royal Cornwall Hospital, Truro, UK), Stephen Kelly (Kings College Hospital, London, UK), Christopher Swearingen (Vanderbilt University, Nashville, TN), Yusuf Yazici (New York University Hospital for Joint Diseases, New York, NY).