Examining radiographic outcomes over time

Determinants of radiographic progression in early psoriatic arthritis: insights from a real-world cohort

OBJECTIVE

Persistent articular inflammation in psoriatic arthritis (PsA) is associated with radiographic damage. Despite advances in diagnosis and therapy, radiographic structural damage remains prevalent in PsA. To elucidate this topic, we studied which baseline clinical characteristics determine radiographic progression.

METHODS

For this analysis, data were used from DEPAR (Dutch South West Psoriatic Arthritis) Study, a real-world cohort of patients with newly diagnosed PsA. Radiographic changes were assessed using the modified Total Sharp/van der Heijde Score (mTSS) for PsA. Univariable-multivariable mixed-effects negative binomial regression analysis was applied to define baseline predictors for radiographic progression over time.

RESULTS

The study included 476 patients with early PsA with 1660 hand and feet radiographs from four different time points (baseline, first, second and third year). The progressive group (n=71) had a higher mTSS compared with the non-progressive group (n=405) at diagnosis (17 (3-36) vs 0 (0-1)). A comparison of the two groups revealed that the progressive group had significantly older (59 (12) vs 49 (13)) and a higher rate of the presence of swollen joints (93% vs 78%) at diagnosis. Multivariable analysis identified age (incidence rate ratio (IRR)=1.10, p=0.000), sex (female) (IRR=0.48, p=0.043) and baseline mTSS (IRR=1.11, p=0.000) as significant determinants of radiographic change over time. For the progressive subset, additionally, the multivariable analysis highlighted baseline Disease Activity in PSoriatic Arthritis (IRR=1.05, p=0.006) and swollen joint count (IRR=1.07, p=0.034) as predictors.

CONCLUSIONS

According to this real-world cohort, patients with early PsA exhibit minimal radiographic progression under current treatment protocols. This study indicates that while old age and initial radiographic damage predict progression, female sex confers a protective effect on it. Furthermore, disease activity score and swollen joints emerged as predictors for radiographic changes during the follow-up in progressive patients.

Early radiological progression remains associated with long-term joint damage in real-world rheumatoid arthritis patients treated to the target of remission

Objective: To evaluate radiological damage and to explore characteristics associated with radiological progression in rheumatoid arthritis (RA) treated to the target of remission in a real-world setting.Method: Baseline to 6 year follow-up data were used from an observational early RA cohort. Radiographs of hands and feet at baseline, 6 months, and 1, 3, and 6 years were scored using the modified Sharp/van der Heijde score (SHS). The threshold for rapid radiological progression (RRP) after 6 months was based on the calculated smallest detectable change of 3.95. Negative binomial generalized linear mixed model and logistic regression analyses were performed to examine which variables were associated with RRP and 6 year radiological progression.Results: Most radiological damage occurred in the first year of treatment [median 2.0 interquartile range (IQR) 1.0-4.0 SHS points] compared to the subsequent 5 years of follow-up (median 3.0 IQR 1.0-5.0 SHS points). While low disease activity was achieved within 6 months on average, 18.8% of the patients developed RRP. Anti-cyclic citrullinated peptide (anti-CCP) positivity [incidence rate ratio (IRR) 1.42, p = 0.03], baseline erosive disease (IRR 1.60, p = 0.02), and RRP (IRR 3.28, p < 0.001) were associated with 6 year radiological progression. Erosive disease was the strongest predictor of RRP (odds ratio 8.8, p < 0.001).Conclusion: Long-term radiological outcome is limited in most real-world RA patients treated to the target of remission, but RRP still occurs. Anti-CCP positivity, baseline erosive disease, and RRP remain associated with long-term radiological outcome.

Assessing prognosis and prediction of treatment response in early rheumatoid arthritis: systematic reviews

BACKGROUND

Rheumatoid arthritis (RA) is a chronic, debilitating disease associated with reduced quality of life and substantial costs. It is unclear which tests and assessment tools allow the best assessment of prognosis in people with early RA and whether or not variables predict the response of patients to different drug treatments.

OBJECTIVE

To systematically review evidence on the use of selected tests and assessment tools in patients with early RA (1) in the evaluation of a prognosis (review 1) and (2) as predictive markers of treatment response (review 2).

DATA SOURCES

Electronic databases (e.g. MEDLINE, EMBASE, The Cochrane Library, Web of Science Conference Proceedings; searched to September 2016), registers, key websites, hand-searching of reference lists of included studies and key systematic reviews and contact with experts.

STUDY SELECTION

Review 1 - primary studies on the development, external validation and impact of clinical prediction models for selected outcomes in adult early RA patients. Review 2 - primary studies on the interaction between selected baseline covariates and treatment (conventional and biological disease-modifying antirheumatic drugs) on salient outcomes in adult early RA patients.

RESULTS

Review 1 - 22 model development studies and one combined model development/external validation study reporting 39 clinical prediction models were included. Five external validation studies evaluating eight clinical prediction models for radiographic joint damage were also included. c-statistics from internal validation ranged from 0.63 to 0.87 for radiographic progression (different definitions, six studies) and 0.78 to 0.82 for the Health Assessment Questionnaire (HAQ). Predictive performance in external validations varied considerably. Three models [(1) Active controlled Study of Patients receiving Infliximab for the treatment of Rheumatoid arthritis of Early onset (ASPIRE) C-reactive protein (ASPIRE CRP), (2) ASPIRE erythrocyte sedimentation rate (ASPIRE ESR) and (3) Behandelings Strategie (BeSt)] were externally validated using the same outcome definition in more than one population. Results of the random-effects meta-analysis suggested substantial uncertainty in the expected predictive performance of models in a new sample of patients. Review 2 - 12 studies were identified. Covariates examined included anti-citrullinated protein/peptide anti-body (ACPA) status, smoking status, erosions, rheumatoid factor status, C-reactive protein level, erythrocyte sedimentation rate, swollen joint count (SJC), body mass index and vascularity of synovium on power Doppler ultrasound (PDUS). Outcomes examined included erosions/radiographic progression, disease activity, physical function and Disease Activity Score-28 remission. There was statistical evidence to suggest that ACPA status, SJC and PDUS status at baseline may be treatment effect modifiers, but not necessarily that they are prognostic of response for all treatments. Most of the results were subject to considerable uncertainty and were not statistically significant.

LIMITATIONS

The meta-analysis in review 1 was limited by the availability of only a small number of external validation studies. Studies rarely investigated the interaction between predictors and treatment.

SUGGESTED RESEARCH PRIORITIES

Collaborative research (including the use of individual participant data) is needed to further develop and externally validate the clinical prediction models. The clinical prediction models should be validated with respect to individual treatments. Future assessments of treatment by covariate interactions should follow good statistical practice.

CONCLUSIONS

Review 1 - uncertainty remains over the optimal prediction model(s) for use in clinical practice. Review 2 - in general, there was insufficient evidence that the effect of treatment depended on baseline characteristics.

STUDY REGISTRATION

This study is registered as PROSPERO CRD42016042402.

FUNDING

The National Institute for Health Research Health Technology Assessment programme.

Systematic review of rheumatoid arthritis clinical studies: Suboptimal statistical analysis of radiological data

INTRODUCTION

The distribution of progression scores in rheumatoid arthritis is highly skewed, requiring advanced statistical analysis techniques, with different techniques resulting in different outcomes.

METHODS

Three databases were searched to identify rheumatoid arthritis clinical trials and observational studies that described radiographic analysis techniques, comparing at least two groups.

RESULTS

Of 5980 identified papers, 225 were eligible for data extraction. Parametric techniques (t-tests, ANOVA or linear regression) were used in 39 studies, of which 18% took the skewed distribution into account. In 53 studies, continuous data was categorized and analyzed with binomial or ordinal methods (chi-square tests or logistic regression). Two studies treated the outcome as a 'count' outcome variable (applying a Poisson).

CONCLUSION

There is large heterogeneity in the analysis strategy of radiographic progression in recent rheumatoid arthritis clinical trials and observational studies, with the majority of studies applying simple, suboptimal or inappropriate methods.