Intercentre variance in patient reported outcomes is lower than objective rheumatoid arthritis activity measures: a cross-sectional study

Inflammatory correlates of the Patient Global Assessment of Disease Activity vary in relation to disease duration and autoantibody status in patients with rheumatoid arthritis

OBJECTIVE

To investigate the associations between the Patient Global Assessment (PGA) and measures of disease activity in patients with rheumatoid arthritis (RA) in relation to disease duration and autoantibody status.

METHODS

1412 patients from three independent cohorts were studied: a prospective cohort of 810 patients with early RA followed up for 24 months; a cross-sectional cohort of 210 patients with established RA in low disease activity; a cross-sectional cohort of 401 patients with established RA in moderate-to-high disease activity. Correlations of the PGA were analysed by Pearson's coefficients and multivariable linear regression at baseline and at months 6, 12 and 24 in the overall populations and after stratification for autoantibody subgroup and remission status (Boolean remission, PGA near remission and non-remission).

RESULTS

In patients with early RA in non-remission, swollen joints correlated independently with the PGA; the correlation became progressively weaker but persisted at all time points in autoantibody-positive patients (adjusted r=0.30-0.12) but lost significance after month 12 in autoantibody-negative patients. Swollen joints independently correlated with the PGA also in near remission until month 12 (adjusted r=0.18-0.16) in autoantibody-positive patients. No independent correlations of inflammatory variables were instead found in patients with established RA irrespective of disease activity and autoantibody status.

CONCLUSIONS

In the early phases of RA, particularly in autoantibody-positive patients, inflammatory variables directly correlate with the PGA across different disease activity states. The optimal cut-off values of the PGA capable of identifying absence of disease should be better explored in relation to disease duration and autoantibody status.

Testing different thresholds for patient global assessment in defining remission for rheumatoid arthritis: are the current ACR/EULAR Boolean criteria optimal?

OBJECTIVES

This study aimed to evaluate different patient global assessment (PGA) cut-offs required in the American College of Rheumatology/European League Against Rheumatism (ACR/EULAR) Boolean remission definition for their utility in rheumatoid arthritis (RA).

METHODS

We used data from six randomised controlled trials in early and established RA. We increased the threshold for the 0-10 score for PGA gradually from 1 to 3 in steps of 0.5 (Boolean1.5 to Boolean3.0) and omitted PGA completely (BooleanX) at 6 and 12 months. Agreement with the index-based (Simplified Disease Activity Index (SDAI)) remission definition was analysed using kappa, recursive partitioning (classification and regression tree (CART)) and receiver operating characteristics. The impact of achieving each definition on functional and radiographic outcomes after 1 year was explored.

RESULTS

Data from 1680 patients with early RA and 920 patients with established RA were included. The proportion of patients achieving Boolean remission increased with higher thresholds for PGA from 12.4% to 19.7% in early and 5.9% to 12.3% in established RA at 6 months. Best agreement with SDAI remission occurred at PGA cut-offs of 1.5 and 2.0, while agreement decreased with higher PGA (CART: optimal agreement at PGA≤1.6 cm; sensitivity of PGA≤1.5 95%). Changing PGA thresholds at 6 months did not affect radiographic progression at 12 months (mean ꙙsmTSS for Boolean, 1.5, 2.0, 2.5, 3.0, BooleanX: 0.35±5.4, 0.38±5.14, 0.41±5.1, 0.37±4.9, 0.34±4.9, 0.27±4.7). However, the proportion attaining HAQ≤0.5 was 90.2%, 87.9%, 85.2%, 81.1%, 80.7% and 73.1% for the respective Boolean definitions.

CONCLUSION

Increasing the PGA cut-off to 1.5 cm would provide high consistency between Boolean with the index-based remission; the integer cut-off of 2.0 cm performed similarly.

Predictive factors for work-day loss in Behçet's syndrome: A multi-center study

OBJECTIVE

The aim of this multi-center study was to assess predictive factors for work-day loss as an indirect cost element in Behçet's syndrome (BS).

METHODS

In this cross-sectional, multi-center study, 834 BS patients (F/M: 441/393, age mean: 38.4 ± 10.9 years) were included. Data were collected by a questionnaire regarding treatment protocols, disease duration, smoking pattern, frequency of medical visits during the previous year and self-reported work-day loss during the previous year.

RESULTS

Work-day loss was observed in 16.2% of patients (M/F: 103/32). The percentages of being a smoker (81.8%), using immunosuppressive (IS) medications (82%), and having disease duration <5 years (74%) were higher in male patients with work-day loss (P < .05). The majority of males (90.9%) had more than four clinic visits during the previous year. Moreover, the mean work-day loss (30.8 ± 57.7 days) was higher in patients with vascular involvement (56.1 ± 85.9) than those without (26.4 ± 50.6 days) (P = .046). In addition, increased frequency of ocular involvement (25.9%) was also observed in patients with work-day loss compared to others (8.6%) (P = .059).

CONCLUSION

Work-day loss was associated with both vascular and ocular involvement. Close associations were observed among male gender, early period of the disease, frequent medical visits, being a smoker and treatment with IS medications in patients with work-day loss.

Common Evaluations of Disease Activity in Rheumatoid Arthritis Reach Discordant Classifications across Different Populations

Objectives

The classification of disease activity states in rheumatoid arthritis (RA) can be achieved through disease activity indices, such as the Disease Activity Score in 28 joints erythrocyte sedimentation rate (DAS28-ESR), the Simplified Disease Activity Index (SDAI), and the Clinical Disease Activity Index (CDAI). Subjective measurements, such as patient reported outcomes have been incorporated into several of these indices alongside more objective assessments, such as increases in the ESR and C-reactive protein. Moreover, while they use similar criteria, different indices weight these criteria to different extents. Therefore, the classifications based on each evaluation may not always be the same. We aim to compare the performance of the three indices and their individual components in two different populations.

Methods

Data from Dutch and Portuguese adherent centers were extracted from the METEOR database, a multinational collaboration on RA. We included a total of 24,605 visits from Dutch centers (from 5,870 patients) and 20,120 visits from Portuguese centers (from 3,185 patients). We compared the disease activity states as evaluated by the DAS28-ESR, CDAI, and SDAI across the two populations. In addition, we analyzed the individual components of each evaluation, including their respective contributions to the outcome, in each population.

Results

We found significant differences in the disease activity states classified with the DAS28-ESR between the two populations. SDAI and CDAI had more congruous results. While the proportion of visits to Dutch and Portuguese centers that were classified as “in remission” was very similar between the CDAI and SDAI, the DAS28-ESR gave discordant results. Dutch patients had lower ESRs, which is more heavily weighted in the DAS28-ESR. In addition, even though the mean physicians’ global assessment values did not vary significantly for Dutch vs Portuguese physicians, we found that doctors at Portuguese centers overall scored the physician’s global assessment lower than Dutch physicians for patient visits classified by disease activity state.

Conclusion

While the CDAI and SDAI assigned disease activity states that were largely similar, the DAS28-ESR was often discordant across the two populations. Moreover, we found that physicians, more than patients, evaluated disease activity differently among the Portuguese and Dutch populations.