The Scottish Early Rheumatoid Arthritis (SERA) Study: an inception cohort and biobank

Efficacy and safety of drugs for psoriasis patients with mental disorders: A systematic review

BACKGROUND

The emergence of biological agents and small molecule drugs has revolutionized the treatment landscape for psoriasis, yet there remains a lack of systematic reviews elucidating the efficacy and safety of drugs for patients with psoriasis and mental disorders (MD). The aim was to systemically evaluate the efficacy and safety of FDA-approved psoriasis drugs on MD symptoms and MD drugs on psoriasis symptoms.

METHODS

We conducted comprehensive literature searches of PubMed, Embase, and the Cochrane Library from inception to March 24, 2024, identifying 116 relevant studies for inclusion.

RESULTS

Our review encompasses 62 clinical trials and 54 case reports/series. Analyses of clinical trials revealed a positive impact of psoriasis drugs on MD, with notable exceptions including lithium and benzodiazepine receptor agonists, which exhibited adverse effects on psoriasis. Furthermore, analysis of case reports/series highlighted the efficacy of drugs such as apremilast, etanercept, infliximab, and secukinumab in ameliorating MD symptoms, contrasting with detrimental effects observed with methotrexate (MTX), cyclosporine, adalimumab, and secukinumab. Notably, tumor necrosis factor alpha (TNF-α) inhibitors and interleukin inhibitors demonstrated superior efficacy compared to conventional treatments. In the anxiety group, secukinumab showed the largest effective size as assessed by the HADS-A index; In the depression group, ixekizumab showed the largest effective size assessed by the QIDS-SR16 index.

LIMITATIONS

The extracted data cannot be meta-analyzed, as the measurement scale is not uniform.

CONCLUSIONS

This systematic review provides robust evidence regarding treatment options for individuals with psoriasis and MD, emphasizing the potential benefits of specific drugs in managing both conditions concurrently.

Recognition and control of neutrophil extracellular trap formation by MICL

Regulation of neutrophil activation is critical for disease control. Neutrophil extracellular traps (NETs), which are web-like structures composed of DNA and neutrophil-derived proteins, are formed following pro-inflammatory signals; however, if this process is uncontrolled, NETs contribute to disease pathogenesis, exacerbating inflammation and host tissue damage1,2. Here we show that myeloid inhibitory C-type lectin-like (MICL), an inhibitory C-type lectin receptor, directly recognizes DNA in NETs; this interaction is vital to regulate neutrophil activation. Loss or inhibition of MICL functionality leads to uncontrolled NET formation through the ROS-PAD4 pathway and the development of an auto-inflammatory feedback loop. We show that in the context of rheumatoid arthritis, such dysregulation leads to exacerbated pathology in both mouse models and in human patients, where autoantibodies to MICL inhibit key functions of this receptor. Of note, we also detect similarly inhibitory anti-MICL autoantibodies in patients with other diseases linked to aberrant NET formation, including lupus and severe COVID-19. By contrast, dysregulation of NET release is protective during systemic infection with the fungal pathogen Aspergillus fumigatus. Together, we show that the recognition of NETs by MICL represents a fundamental autoregulatory pathway that controls neutrophil activity and NET formation.

Time-varying risks of infection in patients as they proceed through the phases of 'pre-RA': results from the Scottish Early RA inception cohort

ObjectiveRheumatoid arthritis (RA) develops after progressing through sequential 'pre-RA' phases. The mechanisms driving progression from one phase to the next remain poorly understood. This study examined the longitudinal rates of community and hospital infections in patients during sequential stages of pre-RA and early arthritis.

METHODS

The Scottish Early RA inception cohort recruited patients with newly diagnosed RA. Incidences of infection were determined from community antibiotic prescriptions and serious infections were determined by hospital discharge coding. Dates of diagnosis and symptom onset allowed identification of asymptomatic/symptomatic pre-RA and early arthritis eras to analyse infection rates over time compared with age- and sex-matched controls.

RESULTS

The incidence rate ratio (IRR) seen in the period 0-6 months prior to symptom onset was 1.28 (95% CI 1.15 to 1.42). In 'symptomatic pre-RA', the IRR was 1.33 (95% CI 1.18 to 1.49) which persisted into 'early arthritis'. The rate of hospital admissions was numerically greater in 'pre-RA' and significantly greater in 'early arthritis' (IRR 1.82, 95% CI 1.32 to 2.46).

CONCLUSION

Antibiotic risk is increased in patients with 'pre-RA' at least 6 months before symptoms develop, and this persists throughout the symptomatic pre-RA phase. Infections may be important in the mechanisms that drive progression to RA or be a manifestation of immune dysfunction (or both). These observations could inform safety and efficacy considerations for interventions in pre-RA to prevent progression. Patients with 'pre-RA' with recurrent antibiotic use may also be an identifiable 'high risk' group that could enrich the study population for intervention studies in pre-RA.

Association between risk, duration and cause of hospitalisations in people with rheumatoid arthritis and multimorbidity in the UK Biobank and Scottish Early Rheumatoid Arthritis (SERA) cohorts: Longitudinal observational study

OBJECTIVES

To investigate association between presence of multimorbidity in people with established and early rheumatoid arthritis (RA) and risk, duration and cause of hospitalisations.

DESIGN

Longitudinal observational study.

SETTING

UK Biobank, population-based cohort recruited between 2006 and 2010, and the Scottish Early Rheumatoid Arthritis (SERA), inception cohort recruited between 2011 and 2015. Both linked to mortality and hospitalisation data.

PARTICIPANTS

4757 UK Biobank participants self-reporting established RA; 825 SERA participants with early RA meeting the 2010 ACR/EULAR classification criteria. Participants stratified by number of long-term conditions (LTCs) in addition to RA (RA only, RA + 1 LTC and RA + ≥ 2 LTCs) and matched to five non-RA controls.

MAIN OUTCOME MEASURES

Number and duration of hospitalisations and their causes. Incidence rate ratios (IRR) and 95% confidence intervals (CI) calculated using negative binomial regression models.

RESULTS

Participants with RA + ≥ 2 LTCs experienced higher hospitalisation rates compared to those with RA alone (UK Biobank: IRR 2.10, 95% CI 1.91 to 2.30; SERA: IRR 1.74, 95% CI 1.23 to 2.48). Total duration of hospitalisation in RA + ≥ 2 LTCs was also higher (UK Biobank: IRR 2.48, 95% CI 2.17 to 2.84; SERA: IRR 1.90, 95% CI 1.07 to 3.38) than with RA alone. Rate and total duration of hospitalisations was higher in UK Biobank RA participants than non-RA controls with equivalent number of LTCs. Hospitalisations for respiratory infection were higher in early RA than established RA and were the commonest cause of hospital admission in early RA.

CONCLUSIONS

Participants with established or early RA with multimorbidity experienced a higher rate and duration of hospitalisations than those with RA alone and with non-RA matched controls.

How do multiple long-term conditions impact on the cost-of-illness in early rheumatoid arthritis?

OBJECTIVE

Multiple long-term conditions (MLTCs) are prevalent in rheumatoid arthritis (RA) and associated with worse outcomes and greater economic burden. However, little is known about the impact of MLTCs on the cost-of-illness (COI) in early RA, including direct and indirect costs. The objective of this study was to quantify this impact on COI.

METHODS

The Scottish Early Rheumatoid Arthritis study is a national cohort of adults with new-onset RA. Direct costs were estimated applying relevant unit costs to health resource utilisation; indirect costs were measured by productivity loss due to health conditions. Two-part models were used, adjusting for age, gender, baseline functional disability and health-related quality of life. The Charlson Comorbidity Index score was calculated using ICD-10 diagnoses. Individuals were defined as 'RA alone', 'RA plus LTC' and 'RA plus MLTCs' according to the number of coexisting LTCs.

RESULTS

Data were available for 818 participants. Average annualised direct costs incurred by people with early RA plus MLTCs (£4444; 95% CI £3100 to £6371) were twice as, and almost five times higher than, those with a single LTC (£2184; 95% CI £1596 to £2997) and those without LTC (£919; 95% CI £694 to £1218), respectively. Indirect costs incurred by RA plus MLTCs (£842; 95% CI £377to £1521) were 3.1 times higher than RA alone (£530; 95% CI £273to £854). The relative proportion of direct costs increased with LTC category, ranging from 77.2% to 84.1%. In addition to increased costs with LTCs, costs also increased with age and were higher for men regardless of LTC category.

CONCLUSIONS

MLTCs impact on COI early in the course of RA. The presence of LTCs is associated with significant increases in both direct and indirect costs among people with early RA.

Depression and anxiety in an early rheumatoid arthritis inception cohort. associations with demographic, socioeconomic and disease features

Objective

Depression and anxiety are not uncommon in Rheumatoid arthritis (RA). It is increasingly recognised that they are associated with high disease activity and worse disease outcomes. We aimed to examine the frequency of depression and anxiety in an early RA inception cohort and to explore associations with disease-related measures.

Methods

The Scottish Early Rheumatoid Arthritis inception cohort recruited newly diagnosed RA patients followed-up 6-monthly. Anxiety and depression were assessed using the hospital anxiety and depression scale. Associations with demographic characteristics and disease-related measures were examined at baseline, 6 months and 12 months.

Results

848 RA patients were included. The prevalence of anxiety and depression at baseline was 19.0% and 12.2%, respectively. Depression and anxiety scores correlated with DAS28 at all time-points (all p<0.0001). In multivariable linear regression, anxiety score at baseline was associated with younger age and Health Assessment Questionnaire (HAQ) score. Anxiety scores at 6 months and 12 months were associated with low body mass index (BMI), baseline anxiety score and current patient global score and HAQ. Depression score at baseline was associated with younger age, being single and HAQ, while depression scores at 6 months and 12 months were associated with male gender (only at 6 months), baseline anxiety and depression scores and current patient global score, HAQ and C-reactive protein (CRP) levels.

Conclusion

Depression and anxiety are associated with disease activity, worse functional status and other variables in early RA. There is a close relationship between CRP and depression but not anxiety.

Socioeconomic inequality in patients with rheumatoid arthritis: a systematic review and meta-analysis

BACKGROUND

Rheumatoid arthritis is a chronic inflammatory and systemic autoimmune disease associated with synovial fluid inflammatory lesions and articular changes. The aim of the present study was to determine socioeconomic inequality in RA patients using a meta-analysis approach.

METHODS

A systematic search of national and international databases of SID, MagIran, Google Scholar, Cochrane, Embase, ScienceDirect, Scopus, PubMed, and Web of Science (WoS) was conducted to find articles published from 1988 to March 2020. Random effects model was used for analysis and heterogeneity of studies was investigated using I² index. Data analysis was then carried out using Comprehensive Meta-Analysis (Ver. 2).

RESULTS

A total of 51 articles with a total sample size of 48,195 individuals were included in the meta-analysis in all the components. The results showed that 18.9% (95% CI: 4.9-13.25%) of patients were single patients, 70.6% (95% CI: 63.5-76.8%) were married, 31.6% (95% CI: 24.5-39.7%) had low economic status, 52.1% (95% CI: 5.8-44.53%) had moderate economic status, level of education was below diploma in 33% (95% CI: 27.1-39.5%) of cases, 36.2% (95% CI: 27.3-46.1%) were smokers, and 8.8% (95% CI: 2.8-24.1%) of patients were unemployed.

CONCLUSION

The results of the present study indicate high socioeconomic inequality in RA patients in the main components of the study. Hence, to improve the aforementioned status and find causes and do the monitoring at all levels, appropriate solutions must be adopted by providing feedback to policy-makers.

KEY POINTS

• The results showed that 18.9% (95% CI: 4.9-13.25%) of patients were single patients. • 70.6% (95% CI: 63.5-76.8%) were married and 31.6% (95% CI: 24.5-39.7%) had low economic status. • 52.1% (95% CI: 5.8-44.53%) had moderate economic status; 36.2% (95% CI: 27.3-46.1%) were smokers.

The impact of autoantibodies against citrullinated, carbamylated, and acetylated peptides on radiographic progression in patients with new-onset rheumatoid arthritis: an observational cohort study

BACKGROUND

A range of anti-modified protein antibodies (AMPAs) are associated with rheumatoid arthritis. We aimed to assess the relationship between AMPA profiles and radiographic progression in patients with new-onset rheumatoid arthritis.

METHODS

In this cohort study, we obtained samples and data from the Scottish Early Rheumatoid Arthritis (SERA) inception cohort and biobank, which recruited patients with new-onset rheumatoid arthritis or undifferentiated arthritis who had at least one swollen joint from 20 hospitals across Scotland. AMPAs in plasma samples were measured by ELISAs at baseline. Paired radiographs of the hands and feet were taken at baseline and at 1 year and were scored with the Sharp-van der Heijde (SvH) method. We calculated differences in radiographic progression using estimated marginal mean changes between baseline and 1 year, with the baseline values of radiographic variables, rheumatoid factor, sex, age at recruitment, symptom duration, and Disease Activity Score 28 with C-reactive protein included as covariates.

FINDINGS

Between March 1, 2011, and April, 30, 2015, 1073 patients were recruited to the SERA study. 362 patients with rheumatoid arthritis were included in our study and had their AMPA profiles determined. Patients were grouped into four main autoantibody profiles by reactivities to post-translational modifications: single positivity for anti-citrullinated peptide antibodies (ACPAs; 73 [20%]); double positivity for ACPAs and anti-acetylated peptide antibodies (AAPAs; 45 [12%]); triple positivity for ACPAs, AAPAs, and anti-carbamylated peptide antibodies (151 [42%]); and AMPA negativity (74 [20%]). 19 (5%) patients were in one of the minor autoantibody groups. Of the 233 patients with both antibody data and radiographs of sufficient quality, triple-positive patients had more radiographic progression between baseline and 12 months (estimated mean change in total SvH score 1·8, 95% CI 0·9-2·6, SE 0·4) than did single-positive patients (0·5, 0·1-1·0, 0·2; estimated mean difference in the total change in SvH score 1·2, 95% CI 0·1-2·4, SE 0·5). There was no difference in radiographic progression between single positive patients and AMPA negative patients (estimated mean change in total SvH score 0·7, 95% CI 0·1-1·4, SE 0·3; estimated mean difference in the total change in SvH score -0·2, 95% CI -1·1 to 0·7, SE 0·4).

INTERPRETATION

This study suggests that the optimal prediction of future rates of radiographic progression in patients with rheumatoid arthritis will require an assessment of autoantibodies against multiple post-translationally modified proteins or peptides.

FUNDING

The EU FP7 HEALTH programme, the Scottish Translational Medicine Research Collaboration, and the Chief Scientist Office Scotland.

Finite sample variance estimation for optimal dynamic treatment regimes of survival outcomes

Deriving valid confidence intervals for complex estimators is a challenging task in practice. Estimators of dynamic weighted survival modeling (DWSurv), a method to estimate an optimal dynamic treatment regime of censored outcomes, are asymptotically normal and consistent for their target parameters when at least a subset of the nuisance models is correctly specified. However, their behavior in finite samples and the impact of model misspecification on inferences remain unclear. In addition, the estimators' nonregularity may negatively affect the inferences under some specific data generating mechanisms. Our objective was to compare five methods, two asymptotic variance formulas (adjusting or not for the estimation of nuisance parameters) to three bootstrap approaches, to construct confidence intervals for the DWSurv parameters in finite samples. Via simulations, we considered practical scenarios, for example, when some nuisance models are misspecified or when nonregularity is problematic. We also compared the five methods in an application about the treatment of rheumatoid arthritis. We found that the bootstrap approaches performed consistently well at the cost of longer computational times. The asymptotic variance with adjustments generally yielded conservative confidence intervals. The asymptotic variance without adjustments yielded nominal coverages for large sample sizes. We recommend using the asymptotic variance with adjustments in small samples and the bootstrap if computationally feasible. Caution should be taken when nonregularity may be an issue.

Adaptive treatment strategies for chronic conditions: shared-parameter G-estimation with an application to rheumatoid arthritis

Most estimation algorithms for adaptive treatment strategies assume that treatment rules at each decision point are independent from one another in the sense that they do not possess any common parameters. This is often unrealistic, as the same decisions may be made repeatedly over time. Sharing treatment-decision parameters across decision points offers several advantages, including estimation of fewer parameters and the clinical ease of a single, time-invariant decision to implement. We propose a new computational approach to estimation of shared-parameter G-estimation, which is efficient and shares the double robustness of the "unshared" sequential G-estimation. We use this approach to analyze data from the Scottish Early Rheumatoid Arthritis (SERA) Inception Cohort.

Time to initiation of biologic disease-modifying antirheumatic drugs in the French cohort ESPOIR

OBJECTIVE

To assess the time to initiation of biologic disease-modifying anti-rheumatic drugs (bDMARDs) in ESPOIR, the French cohort of patients with rheumatoid arthritis (RA), and factors associated with the timing of bDMARD initiation.

METHODS

In total, 658 patients with early RA satisfying the 2010 ACR/EULAR criteria were included between 2003 and 2005 and followed annually for 10 years (end of follow up: 2013-2015). The timing of bDMARD introduction and predictors of use were analysed by the Kaplan-Meier method based on Cox proportional-hazard models.

RESULTS

Overall, 178 patients (31.0%, 95% confidence interval [27.0-34.7]) initiated a bDMARD during the 10-year follow-up, with a mean delay of 43.6 months. The penetration rate was higher during the first 2 years of follow-up (6% between the first and second year, approximately 3.3% each year between the second and seventh year, and<2.0% after the eighth year). The first-used bDMARD was etanercept for 72 patients and adalimumab for 71. On multivariate analysis, Disease Activity Score in 28 joints, radiologic progression and positivity for anti-citrullinated protein antibodies were significantly associated with rapid initiation of a bDMARD (P<0.0001), whereas older age at first joint pain was inversely associated (P<0.0001).

CONCLUSIONS

Although access to bDMARDs is widespread in France, less than one third of patients with early RA in the ESPOIR cohort initiated a bDMARD over the 10-year follow-up. Poor prognostic factors for RA were associated with more rapid initiation, as expected.

In Human Autoimmunity, a Substantial Component of the B Cell Repertoire Consists of Polyclonal, Barely Mutated IgG+ve B Cells

B cells are critical for promoting autoimmunity and the success of B cell depletion therapy in rheumatoid arthritis (RA) confirms their importance in driving chronic inflammation. Whilst disease specific autoantibodies are useful diagnostically, our understanding of the pathogenic B cell repertoire remains unclear. Defining it would lead to novel insights and curative treatments. To address this, we have undertaken the largest study to date of over 150 RA patients, utilizing next generation sequencing (NGS) to analyze up to 200,000 BCR sequences per patient. The full-length antigen-binding variable region of the heavy chain (IgGHV) of the IgG B cell receptor (BCR) were sequenced. Surprisingly, RA patients do not express particular clonal expansions of B cells at diagnosis. Rather they express a polyclonal IgG repertoire with a significant increase in BCRs that have barely mutated away from the germline sequence. This pattern remains even after commencing disease modifying therapy. These hypomutated BCRs are expressed by TNF-alpha secreting IgG^+veCD27^-ve B cells, that are expanded in RA peripheral blood and enriched in the rheumatoid synovium. A similar B cell repertoire is expressed by patients with Sjögren's syndrome. A rate limiting step in the initiation of autoimmunity is the activation of B cells and this data reveals that a sizeable component of the human autoimmune B cell repertoire consists of polyclonal, hypomutated IgG^+ve B cells, that may play a critical role in driving chronic inflammation.

Secular changes in functional disability, pain, fatigue and mental well-being in early rheumatoid arthritis. A longitudinal meta-analysis

OBJECTIVES

To conduct a systematic review and longitudinal meta-analysis of early rheumatoid arthritis (RA) cohorts with long-term data on pain, fatigue or mental well-being.

METHODS

Searches using PUBMED, EMBASE and PyscInfo were performed to identify all early RA cohorts with longitudinal measures of pain, fatigue or mental well-being, along with clinical measures. Using longitudinal meta-analyses, the progression of each outcome over the first 60-months was estimated. Cohorts were stratified based on the median recruitment year to investigate secular trends in disease progression.

RESULTS

Of 7,319 papers identified, 75 met the inclusion criteria and 46 cohorts from 41 publications provided sufficient data on 18,046 patients for meta-analysis. The Disease Activity Scores (DAS28) and the Short-Form 36 (SF-36) Physical Component Score (PCS) indicated that post-2002 cohorts had statistically significant improvements over the first 60-months compared to pre-2002 cohorts, with standardised mean differences (SMD) of 0.86 (95% Confidence Intervals 0.34 to 1.37) and 0.76 (95% CI 0.25 to 1.27) respectively at month-60. However, post-2002 cohorts indicated statistically non-significant improvements in pain, fatigue, functional disability and SF-36 Mental Component Score (MCS) compared to pre-2002 cohorts, with SMD of 0.24 (95% CI -0.25 to 0.74), 0.38 (95% CI -0.11 to 0.88), 0.34 (95% CI -0.15-0.84) and -0.08 (95% CI -0.41 to 0.58) at month-60 respectively.

CONCLUSIONS

Recent cohorts indicate improved levels of disease activity and physical quality of life, however this has not translated into similar improvements in levels of pain, fatigue and functional disability by 60-months.

Neutropaenia in early rheumatoid arthritis: frequency, predicting factors, natural history and outcome

Objectives

To determine the frequency, severity and natural history of neutropaenia in early rheumatoid arthritis (RA), explore its associations with clinical features and assess its impact on clinical management.

Methods

The Scottish Early Rheumatoid Arthritis inception cohort prospectively recruited patients with newly diagnosed RA and followed them up every 6 months. Patients with RA who developed at least one episode of neutropaenia (grade 1: <2.0×10^9/L; grade 2: <1.5×10^9/L; grade 3: <1.0×10^9/L; grade 4: <0.5×10^9/L) were compared with those who did not. Comparisons were also made between patients who experienced one or more episodes of neutropaenia and between patients with different neutropaenia grades.

Results

77 neutropaenia episodes were recorded in 58 of 771 (7.5%) patients with RA, who were followed up for a median (range) of 18 (6-48) months. Neutropaenia occurred at a median (range) of 12 (0-120) months after RA diagnosis. The majority had mild neutropaenia (grade 1: n=42; grade 2: n=14; grade 3: n=1; grade 4: n=1). Neutropaenia was transient (single episode) in the majority (44; 75.8%) of cases but led to treatment discontinuation in 14 (24.1%) patients. Patients who developed neutropaenia were more likely to be female (p=0.01) and non-smokers (p=0.007) and had lower baseline neutrophil levels (p<0.0001). Binomial regression analysis confirmed the latter (p<0.0001, B: -0.491) as neutropaenia predictor. The rate of infections did not differ between patients who developed neutropaenia and those who did not (p=0.878).

Conclusion

Neutropaenia was a common finding in this cohort. It was usually mild, transient and not associated with increased infection rates. Neutropaenia occurrence was associated with non-smoking, female gender and lower baseline neutrophil levels.

Chromosome conformation signatures define predictive markers of inadequate response to methotrexate in early rheumatoid arthritis

Background

There is a pressing need in rheumatoid arthritis (RA) to identify patients who will not respond to first-line disease-modifying anti-rheumatic drugs (DMARD). We explored whether differences in genomic architecture represented by a chromosome conformation signature (CCS) in blood taken from early RA patients before methotrexate (MTX) treatment could assist in identifying non-response to DMARD and, whether there is an association between such a signature and RA specific expression quantitative trait loci (eQTL).

Methods

We looked for the presence of a CCS in blood from early RA patients commencing MTX using chromosome conformation capture by EpiSwitch™. Using blood samples from MTX responders, non-responders and healthy controls, a custom designed biomarker discovery array was refined to a 5-marker CCS that could discriminate between responders and non-responders to MTX. We cross-validated the predictive power of the CCS by generating 150 randomized groups of 59 early RA patients (30 responders and 29 non-responders) before MTX treatment. The CCS was validated using a blinded, independent cohort of 19 early RA patients (9 responders and 10 non-responders). Last, the loci of the CCS markers were mapped to RA-specific eQTL.

Results

We identified a 5-marker CCS that could identify, at baseline, responders and non-responders to MTX. The CCS consisted of binary chromosome conformations in the genomic regions of IFNAR1, IL-21R, IL-23, CXCL13 and IL-17A. When tested on a cohort of 59 RA patients, the CCS provided a negative predictive value of 90.0% for MTX response. When tested on a blinded independent validation cohort of 19 early RA patients, the signature demonstrated a true negative response rate of 86 and a 90% sensitivity for detection of non-responders to MTX. Only conformations in responders mapped to RA-specific eQTL.

Conclusions

Here we demonstrate that detection of a CCS in blood in early RA is able to predict inadequate response to MTX with a high degree of accuracy. Our results provide a proof of principle that a priori stratification of response to MTX is possible, offering a mechanism to provide alternative treatments for non-responders to MTX earlier in the course of the disease.

Electronic supplementary material

The online version of this article (10.1186/s12967-018-1387-9) contains supplementary material, which is available to authorized users.

A Longitudinal Study of Ambulatory Physician Encounters, Emergency Room Visits, and Hospitalizations by Patients with Rheumatoid Arthritis: A 13-year Population Health Study

Objective.

To determine total physician encounters, emergency room (ER) visits, and hospitalizations in an incident cohort of rheumatoid arthritis (RA) cases and matched control patients over 13 years.

Methods.

A retrospective cohort study was performed using administrative healthcare data from about 1 million people with access to universal healthcare. Using the International Classification of Diseases, 9th ed (ICD-9) and ICD-10 diagnostic codes, 7 RA case definitions were used. Each case was matched by age and sex to 4 randomly selected controls. Data included physician billings, ER visits, and hospital discharges over 13 years.

Results.

The number of incident RA cases varied from 3497 to 27,694, depending on the case definition. The mean age varied from 54.3 to 65.0 years, and the proportion of women from 67.8% to 71.3%. The number of physician encounters by patients with RA was significantly higher than by controls. It was highest in the index year and declined promptly thereafter for all case definitions and by 12.2%–46.8% after 10 years. Encounters with subspecialty physicians fell by 61% (rheumatologists) and 34% (internal medicine). In contrast, clinical encounters with family physicians and other physicians fell by only 9%. Visits to the ER and hospital admissions were also significantly higher in RA cases, particularly early in the disease, and fell significantly over the followup.

Conclusion.

In patients with RA, healthcare use is highest in the first year following the diagnosis, which is also the time of maximal involvement by rheumatologists. Use declines over time, and encounters with patients’ family physicians predominate over other physician groups.