Using real-world data to dynamically predict flares during tapering of biological DMARDs in rheumatoid arthritis: development, validation, and potential impact of prediction-aided decisions.

BACKGROUND: Biological disease-modifying antirheumatic drugs (bDMARDs) are effective in the treatment of rheumatoid arthritis. However, as bDMARDs may also lead to adverse events and are expensive, tapering them is of great clinical interest. Tapering according to disease activity-guided dose optimization (DGDO) does not seem to affect long term remission rates, but flares are frequent during this process. Our objective was to develop a model for the prediction of flares during bDMARD tapering using data from routine care and to evaluate its potential clinical impact. METHODS: We used a joint latent class model to repeatedly predict the probability of a flare occurring within the next 3 months. The model was developed using longitudinal data on disease activity (DAS28) and other routine care data from two clinics. Predictive accuracy was assessed in cross-validation and external validation was performed with data from the DRESS (Dose REduction Strategy of Subcutaneous tumor necrosis factor inhibitors) trial. Additionally, we simulated the reduction in number of flares and bDMARD dose when implementing the model as a decision aid during bDMARD tapering in the DRESS trial. RESULTS: Data from 279 bDMARD courses were used for model development. The final model included two latent DAS28-trajectories, bDMARD type and dose, disease duration, and seropositivity. The area under the curve of the final model was 0.76 (0.69-0.83) in cross-validation and 0.68 (0.62-0.73) in external validation. In simulation of prediction-aided decisions, the mean number of flares over 18 months decreased from 1.21 (0.99-1.43) to 0.75 (0.54-0.96). The reduction in he bDMARD dose was mostly maintained, increasing from 54 to 64% of full dose. CONCLUSIONS: We developed a dynamic flare prediction model, exclusively based on data typically available in routine care. Our results show that using this model to aid decisions during bDMARD tapering may significantly reduce the number of flares while maintaining most of the bDMARD dose reduction. TRIAL REGISTRATION: The clinical impact of the prediction model is currently under investigation in the PATIO randomized controlled trial (Dutch Trial Register number NL9798).

Comparison of disease activity measures in early psoriatic arthritis in usual care.

OBJECTIVES: To compare responsiveness and longitudinal validity of Disease Activity Score 28 (DAS28), Disease Activity index for PSoriatic Arthritis (DAPSA), Composite Psoriatic Disease Activity Index (CPDAI), Psoriatic ArthritiS Disease Activity Score (PASDAS), GRAppa Composite scorE (GRACE) and Minimal Disease Activity (MDA) in usual care PsA patients, within 1 year after diagnosis. METHODS: Data collected in the Dutch southwest early PsA cohort (DEPAR) were used. Responsiveness was assessed using effect size (ES), standardized response mean (SRM), and discrimination between different general health states. Longitudinal validity was tested using mixed models with outcomes health-related quality of life (HRQOL), productivity and disability. RESULTS: Responsiveness was highest for PASDAS, with ES 1.00 and SRM 0.95, lowest for DAPSA, with ES 0.73 and SRM 0.71, and in between for DAS28, CPDAI and GRACE. Differences in general health were best discriminated with PASDAS and GRACE. Patients reporting stable or worsening general health could not be distinguished by DAS28 or CPDAI. Discrimination was better using DAPSA, but worse than when using PASDAS and GRACE. Longitudinal evolvement of HRQOL and productivity had the highest association with low disease activity according to GRACE, followed by PASDAS, MDA, DAPSA, DAS28, with the lowest association for CPDAI. CONCLUSION: PASDAS and GRACE were superior with respect to responsiveness, and together with MDA best related to longitudinal evolvement of HRQOL, productivity and disability. Responsiveness and longitudinal validity of most outcomes were inferior for DAS28, DAPSA and CPDAI. As alternatives to the continuous measure DAPSA, use of PASDAS or GRACE should be considered.

Time to minimal disease activity in relation to quality of life, productivity, and radiographic damage 1 year after diagnosis in psoriatic arthritis.

BACKGROUND: In a cohort of patients with newly diagnosed psoriatic arthritis (PsA) who received usual care, we investigated the impact of time elapsed to minimal disease activity (MDA) on health-related quality of life (HRQoL), work productivity, and radiographic damage throughout the first year after diagnosis. METHODS: Data collected in the Dutch southwest early PsA cohort (DEPAR) study were analyzed. These three-monthly data encompassed disease activity, HRQOL was measured with the Short Form 36 (SF36) Physical Component Scale (SF36-PCS) and Mental Component Scale, and productivity was measured with the Productivity Cost Questionnaire. Radiographic damage was scored at baseline and at 12 months with the PsA-modified Sharp/van der Heijde score. Patients were classified by time to MDA as in early (within 3 months), late (at 6-12 months), and never MDA in the first year. RESULTS: We included 296 patients who had had their 1-year outpatient visit (mean age 51 years, 53% male). Ninety-six (32%) were classified as early MDA, 78 (26%) as late MDA, and 98 (33%) as never MDA. Data of 24 patients (8%) were missing. SF36-PCS and productivity scores improved after gaining MDA, but remained low in never MDA patients. At 1 year, SF36-PCS and productivity scores were similar in early and late MDA patients. Radiographic progression rate was low and similar in all groups. CONCLUSION: Gaining MDA was associated with considerable improvement in HRQoL and functioning, irrespective of time to first MDA. In the one third of patients not in MDA in the first year, the disease had a substantial health impact.

Influence of Disease Manifestations on Health-related Quality of Life in Early Psoriatic Arthritis.

OBJECTIVE: Psoriatic arthritis (PsA) is a multifaceted disease. Affecting joints, skin, entheses, and dactylitis, its effect on health-related quality of life (HRQOL) could be substantial. We aim to assess HRQOL in patients newly diagnosed with PsA and analyze its associations with disease manifestations. METHODS: Data collected at time of diagnosis from patients with PsA included in the Dutch south-west Early Psoriatic Arthritis cohort (DEPAR) study were used. HRQOL was assessed using 8 domains of the Medical Outcomes Study Short Form-36 (SF-36) questionnaire. Patients were classified based on primary manifestation in arthritis subtypes (i.e., mono-, oligo-, or polyarthritis) and other subtypes (i.e., enthesitis, dactylitis, and axial disease). In all patients, presence of arthritis, enthesitis, dactylitis, psoriasis, and chronic inflammatory back pain was determined. Multivariable linear regression was used to determine associations of PsA manifestations with HRQOL. RESULTS: Of 405 patients, primary manifestation was peripheral arthritis in 320 (78 monoarthritis, 151 oligoarthritis, and 91 polyarthritis), enthesitis in 37, axial disease in 9, and dactylitis in 39. Mean scores of SF-36 domains were lower than the Dutch reference population and similar across arthritis subtypes. A higher number of enthesitis locations and tender joints, and presence of chronic back pain, were independently associated with worse SF-36 scores. Psoriasis and dactylitis were not associated with worse scores. CONCLUSION: HRQOL was diminished in PsA at time of diagnosis compared to the Dutch reference population, and tender joints, enthesitis at clinical examination, and back pain as indicators of pain affected HRQOL.

Burden of Psoriatic Arthritis According to Different Definitions of Disease Activity: Comparing Minimal Disease Activity and the Disease Activity Index for Psoriatic Arthritis.

OBJECTIVE: Treat-to-target strategies have improved outcomes in rheumatic diseases. In psoriatic arthritis (PsA), the proposed targets are the multidimensional target minimal disease activity (MDA) and the articular target Disease Activity index for PsA (DAPSA). The aim of this study was to compare the disease burden of PsA in patients with low disease activity according to the 2 definitions, MDA and DAPSA low disease activity (DAPSA-LDA), 1 year after diagnosis. METHODS: We obtained data on MDA, DAPSA-LDA and disease burden 1 year after diagnosis for patients included in the Dutch southwest early PsA cohort. Disease burden was assessed in 2 domains: "Body functions," including the Short Form 36 bodily pain (SF-36 BP) measure, and "Activity," including the Health Assessment Questionnaire (HAQ). RESULTS: Among the 292 patients included, 48% achieved MDA and 74% achieved DAPSA-LDA. Average scores for Body functions and Activity were better in patients who achieved MDA and those who achieved DAPSA-LDA. The scores were significantly better in the 46% of patients who achieved both MDA and DAPSA-LDA than in the 29% of patients who achieved only DAPSA-LDA. The average SF-36 BP score was higher in patients achieving both targets (73.8; 95% confidence interval [95% CI] 71.1-76.5) than in patients achieving only DAPSA-LDA (57.6; 95% CI 54.5-60.8). Similarly, mean HAQ scores measuring Activity were 0.21 (95% CI 0.15-0.26) and 0.63 (95% CI 0.53-0.72), respectively. CONCLUSION: Among patients with newly diagnosed PsA, 48% achieved MDA and 74% achieved DAPSA-LDA after 1 year of receiving usual care. The average disease burden was better in patients who achieved MDA and those who achieved DAPSA-LDA. Also, patients who achieved only DAPSA-LDA reported worse outcomes than those who also achieved MDA.