Hospitalization rates and utilization among patients with rheumatoid arthritis: a population-based study from 1987 to 2012 in Olmsted County, Minnesota

Continuity of Care Within a Single Patient Support Program for Patients with Rheumatoid Arthritis Prescribed Second or Later Line Advanced Therapy

INTRODUCTION

Guidelines suggest patients with rheumatoid arthritis (RA) inadequately controlled by tumor-necrosis-factor-inhibitors (TNFis) may benefit from switching to Janus-kinase-inhibitors (JAKis); however, care coordination and access can be complicated. Disruptions in transitioning to JAKi treatment could lead to disease flares requiring hospitalization; however, transitioning between products within the same patient support program (PSP) services aimed at ensuring continuity of care may minimize disruptions.

METHODS

A retrospective, longitudinal cohort study of adult patients with RA newly prescribed JAKi following TNFi treatment in the Symphony Health claims database. Patients with baseline TNFi use and ≥ 6 months of data before (baseline) and after (follow-up) the initial JAKi claim (approved or denied) were included. Cohorts were defined by transitions between products within the same PSP [adalimumab (ADA) and upadacitinib (UPA)] or not. Disruptions were defined as gap in care ≥ 15 days due to failure/delay in receiving coverage approval or picking up an approved prescription. Disruptions followed by JAKi dispense were considered temporary and those without permanent. Odds ratios (ORs) of disruption and hospitalization were estimated from logistic regressions controlling for patient characteristics and treatment history.

RESULTS

A total of 2371 patients were included: 317 transitioning from ADA-UPA, 321 TNFi-UPA, 860 ADA-another JAKi, and 873 another TNFi-another JAKi. Temporary and permanent disruptions increased odds of hospitalization by 47% and 123% (both p < 0.05). Temporary disruption rates were lowest for ADA-UPA patients (19%) compared to other TNFi-UPA (25%; OR = 1.46), ADA-other JAKi (29%; OR = 1.59), and other TNFi-other JAKi (31%; OR = 1.74), all p < 0.05. For transitions to UPA, temporary disruptions were lower for patients using the PSP (17%) versus not (24%; OR = 1.45, p < 0.05). No differences were found for permanent disruptions.

CONCLUSION

Disruptions for patients with RA transitioning from TNFi to JAKi treatment are associated with increased hospitalization rates. Transitioning between drugs within the same PSP could lower the risk of disruption.

Health-care utilization among dementia patients with or without comorbid depression in Taiwan: A nationwide population-based longitudinal study

BACKGROUND

Few studies have examined the association of comorbid depression with health-care utilization among dementia patients. This study compared health-care utilization between dementia patients with and without comorbid depression.

METHODS

Using Taiwan's National Health Insurance Research Database, we identified 10,710 patients with newly diagnosed dementia between 2005 and 2014: 1785 had comorbid depression (group 1) and 8925 did not (group 2). Patients were tracked for 1 year to evaluate outpatient, emergency, and inpatient service utilization and length of hospital stay (LOS). Multivariable regression was applied to examine the association between comorbid depression and health-care utilization and analyze factors associated with inpatient visits and LOS.

RESULTS

Group 1 had significantly fewer outpatient visits (β = -0.115; p < 0.001), more inpatient visits (β = 0.157; p = 0.005), and a longer LOS (β = 0.191; p < 0.001) than did group 2. The groups did not differ significantly in emergency visits (β = 0.030; p = 0.537). In group 1, age, gender, and specific comorbidities were predictors of inpatient visits; those factors and salary-based insurance premiums were predictors of LOS.

CONCLUSION

Group 1 utilized less outpatient care but more inpatient care, suggesting health-care service for these patients may be needed to improvement.

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.

Use of a Novel Electronic Auto-Notification Process to Manage Transitions of Care in Patients With Rheumatic Disease Receiving Disease-Modifying Antirheumatic Drug Therapy

OBJECTIVE

To integrate an auto-notification system into clinical workflow, so timely communication of sentinel events (elective surgery, hospital admission, or emergency room [ER] visit) in immunosuppressed patients with rheumatic disease happened by design.

METHODS

We developed an algorithm that triggered auto-notification within the electronic medical record to rheumatology when a patient experienced a sentinel event. A telephone encounter was created that included event type, baseline therapy, and event date. This was forwarded to the rheumatologist, who recorded guideline-driven recommendations and returned it to nursing. Instructions were included to communicate recommendations to the patient, inpatient rheumatology team, or other clinician. This was studied over 4 months at a multispecialty medical practice in Central Pennsylvania. Primary outcomes were percentage of total notifications, notifications by sentinel event type where a change in care plan was recommended, as well as percentage of time where rheumatologists were notified of sentinel events compared to prior to the intervention. The secondary outcome was staff work effort.

RESULTS

Two hundred forty notifications were received (57% for elective surgeries, 39% for ER visits, and 4% for admissions). The need for change in care plan was only 17% for ER visits but was 25% for hospital admissions and 44% for elective surgeries. The percentage of time that rheumatologists were notified of events increased from 57.6% to 100%. The average number of messages received per week was 2.2, requiring a weekly average of 13 minutes of work per physician.

CONCLUSION

We developed an easy, well-received process that hardwires rheumatologist notification sentinel events to facilitate timely care.

Risk of Staphylococcus aureus bacteraemia in patients with rheumatoid arthritis and the effect of orthopaedic implants on the risk: a nationwide observational cohort study

OBJECTIVE

It remains disputed how much the risk of Staphylococcus aureus bacteraemia (SAB) is increased in patients with rheumatoid arthritis (RA), and the extent to which orthopaedic implants explain the risk. We assessed SAB incidence rates (IRs) and incidence rate ratios (IRRs), comparing RA patients with a general population cohort (GPC) and individuals with versus without orthopaedic implants.

METHOD

Danish residents aged ≥ 18 years without prior RA or SAB (=GPC) were followed up for RA and microbiologically verified SAB events (1996-2017). IRRs were calculated by age- and sex-stratified Poisson regression adjusted for age, comorbidities, calendar year, and socioeconomic status.

RESULTS

The GPC comprised 5 398 690 individuals. We identified 33 567 incident RA patients (=RA cohort) (median follow-up 7.3 years, IQR 3.6-12.3). We observed 25 023 SAB events (n = 224 in the RA cohort). IRs per 100 000 person-years were 81.0 (RA cohort) and 29.9 (GPC). IRs increased with age. Adjusted IRRs in 18-59-year-old RA patients were 2.6 (95% confidence interval 1.8-3.7) for women and 1.8 (1.1-3.1) for men, compared with same sex and age group GPC. IRRs declined with age. Compared with the GPC without implants, IRRs for RA patients with implants ranged from 1.9 (1.3-2.8) (women ≥ 70 years) to 5.3 (2.2-12.8) (18-59-year-old men).

CONCLUSION

In this nationwide registry-based cohort study RA was a risk factor for SAB, and orthopaedic implants further increased the risk. Clinicians should be aware of potential SAB in patients with RA and orthopaedic implants.

Hospitalizations Associated With Rheumatic Disease in Alaska, 2015-2018

Objective

Few studies have evaluated hospitalizations associated with rheumatic disease in Indigenous North American populations. The objective of this study was to determine the characteristics of people hospitalized with rheumatic disease in Alaska, including a comparison of hospitalizations for Alaska Native/American Indian (AN/AI) people in Alaska compared with those of other races.

Methods

We used statewide hospital discharge data from the Alaska Health Facilities Data Reporting Program from 2015 to 2018 for this study. Cases were ascertained based on discharge diagnosis (any listed) of a defined set of rheumatic diseases. We determined characteristics associated with rheumatic disease hospitalizations, including age, gender, and race. Using multivariate modeling, we determined risk factors for hospitalization overall, as well as for specific rheumatic diseases. We compared characteristics of hospital encounters for people with or without rheumatic diseases and by race.

Results

We identified 15975 people ever hospitalized with rheumatic disease in the study period and 87138 controls hospitalized but without any rheumatic disease diagnosis. Cases were older than controls and more likely to be female. The three most common types of rheumatic disease associated with hospitalization were osteoarthritis, gout, and rheumatoid arthritis. Compared with other races, AN/AI people were more likely to be hospitalized with rheumatic disease, and this association was true for all specific diseases other than gout.

Conclusion

Hospitalizations associated with rheumatic disease are common in Alaska, with an increased likelihood of hospitalization for AN/AI people. This adds to the literature on health disparities in Indigenous North American populations.

Interleukin 27 Signaling in Rheumatoid Arthritis Patients: Good or Evil?

The occurrence and development of rheumatoid arthritis (RA) is regulated by numerous cytokines. Interleukin 27 (IL-27) is a soluble cytokine that exerts biological effects by regulating the Janus tyrosine kinase (JAK)/signal transducer and activator of the transcription (STAT) signaling pathway via the IL-27 receptor. IL-27 is known for its pleiotropic roles in modulating inflammatory responses. Previous studies found that IL-27 levels are elevated in RA blood, synovial fluid, and rheumatoid nodules. Cellular and animal experiments indicated that IL-27 exerts multiple regulatory functions in RA patients via different mechanisms. IL-27 inhibits ectopic-like structure (ELS) formation and CD4⁺ T helper type 2 (Th2) cell, CD4⁺ T helper type 17 (Th17) cell, and osteoclast differentiation in RA, contributing to alleviating RA. However, IL-27 promotes Th1 cell differentiation, which may exacerbate RA synovitis. Moreover, IL-27 also acts on RA synovial fibroblasts (RA-FLSs) and regulatory T cells (Tregs), but some of its functions are unclear. There is currently insufficient evidence to determine whether IL-27 promotes or relieves RA. Targeting IL-27 signaling in RA treatment should be deliberate based on current knowledge.

Rheumatoid Arthritis in Silica-Exposed Workers

Few studies have examined rheumatoid arthritis (RA) risk and severity in Korean workers exposed to silica. We compared the hospitalization risk of RA between silica-exposed workers and the general Korean population. The study cohort consisted of male workers exposed to silica who had undergone at least one silica-associated special medical examination between 1 January 2000 and 31 December 2004 (N = 149,948). The data were from the Korea Occupation Safety and Health Agency. RA morbidity based on hospital admission records was estimated from 2000 to 2005 using the Korea National Health Insurance Service claims data. The standardized admission ratio (SAR) was calculated by dividing the observed number of admissions in silica-exposed workers by the expected number of admissions in the general reference population. For the sum of “Seropositive rheumatoid arthritis” (M05) and “Other rheumatoid arthritis” (M06), the SAR was higher in the silica-exposed group (1.34, 95% CI 1.08–1.64). For M05, workers with <10 years of silica exposure had a significantly higher SAR (2.54, 95% CI 1.10–5.01) than the general population. More silica-exposed workers without a diagnosis of pneumoconiosis were hospitalized for RA than the general population. Our analysis reaffirms the link between silica exposure and RA and suggests that the severity of RA is increased by silica. Further studies of silica-exposed workers with longer follow-up are needed.

Risk of venous thromboembolism associated with methotrexate versus hydroxychloroquine for rheumatoid arthritis: A propensity score-matched cohort study

AIMS

Patients with rheumatoid arthritis (RA) have an increased risk of venous thromboembolism (VTE), likely related to underlying inflammation. We examined VTE risk associated with two commonly used immunomodulators in RA patients, methotrexate and hydroxychloroquine.

METHODS AND RESULTS

Using U.S. Medicare claims data (2008-2017), we identified RA patients (≥65 years) who initiated methotrexate or hydroxychloroquine without prior use of any immunomodulators. The primary outcome was VTE, a composite of pulmonary embolism (PE) or deep vein thrombosis (DVT). Secondary outcomes included PE, DVT, and all-cause mortality. After 1:1 propensity score matching for confounding control, we identified 26,534 pairs of methotrexate and hydroxychloroquine initiators (mean (SD) age 74 (7) years; 79% female). During a total of 56,686 person-years of follow-up, 208 methotrexate and 83 hydroxychloroquine initiators developed VTE. The incidence rate of VTE was higher among methotrexate initiators (6.94/1,000 person-years) than hydroxychloroquine initiators (3.11/1,000 person-years) with a hazard ratio (HR) of 2.26 (95% CI 1.75, 2.91). Methotrexate initiators had a greater risk of PE (HR 3.30, 95% CI 2.28, 4.77) and DVT (HR 1.53, 95% CI 1.07, 2.19) than hydroxychloroquine initiators. All-cause mortality was similar between the two groups (HR 0.91, 95% CI 0.83, 1.00).

CONCLUSION

In this large real-world cohort of older RA patients, treatment with methotrexate was associated with a 2-fold increased risk of VTE relative to hydroxychloroquine, although all-cause mortality was similar. Future experimental studies with non-user control groups are needed to determine the causal relationships between the study drugs and VTE and whether methotrexate elevates or hydroxychloroquine reduces the risk of VTE.

Prevalence of hospital readmissions and related factors in patients with autoimmune diseases

Objective

Autoimmune diseases generate an impact on the morbidity and mortality of patients and are a burden for the health system through hospital admissions and readmissions. The prevalence of readmission of patients with these diseases has not yet been described as a group, but rather as sub-phenotype. The objective of this study is to determine the prevalence of hospital readmissions in a Colombian population with autoimmunity and the factors related to readmission.

Methods

All patients with autoimmune diseases who were evaluated by the rheumatology service and hospitalized between August 2018 and December 2019 at the Fundación Hospital Infantil Universitario De San José de Bogotá were described. A bivariate analysis was done, and three multivariate logistic regression models were built with the dependent variable being readmission.

Results

Of the total 199 admissions, 131 patients were evaluated and 32% were readmitted. The most frequent sub-phenotype in both groups (readmission and no readmission) was SLE (51% and 59%). The most frequent cause of hospitalization and readmission was disease activity (68.7% and 64.3%). History of hypertension was associated with readmission (adjusted OR: 2.98-95% CI: 1.15-7.72). In a second model adjusted for confounding variables, no factor was associated. In a third model analyzing the history of kidney disease and previous use of immunosuppressants (adjusted for confounding variables), the previous use of immunosuppressants was related to readmission (OR: 2.78-95% CI 1.12-6.89).

Conclusion

Up to a third of patients with autoimmunity were readmitted and arterial hypertension was an associated factor. This suggested a greater systemic compromise and accumulated damage in patients who have these two conditions that may favor readmission. A history of immunosuppressant use may play a role in readmission, possibly by increasing the risk of developing infections.

Trends in Hospitalization Rates, Major Causes of Hospitalization, and In-Hospital Mortality in Rheumatoid Arthritis in the United States From 2000 to 2014

Objective

To evaluate national trends in hospitalizations and in‐hospital mortality in rheumatoid arthritis (RA).

Methods

National Inpatient Sample from 2000‐2014 and United States Census data were used to study temporal trends in adult RA hospitalizations, reasons for hospitalizations, and in‐hospital mortality.

Results

The data represented 183 983 hospitalizations with a primary diagnosis of RA. The annual rates of hospitalization for the primary diagnosis of RA decreased from 76.54 admissions per 1 million in 2000 to 29.96 per 1 million in 2014 (P trend < 0.0001). The hospital mortality rate declined from 0.70% to 0.41% (P trend < 0.0001) in this group. With a primary or nonprimary diagnosis of RA, the mortality rate ranged between 1.95 and 2.87 (P trend 0.08). For a nonprimary diagnosis of RA, we noted that the proportion of hospitalizations with a diagnosis of myocardial infarction (6.4% in 2000 to 4.6% in 2014; P < 0.001) significantly decreased, but the absolute number of hospitalizations significantly increased. In contrast, the proportion and the absolute number of hospitalizations with any diagnosis of sepsis, congestive heart failure, lung disease, and urinary tract infection increased significantly. We also noted a significant increase in the actual rate and proportions for hospitalizations for hip and knee arthroplasty. Among in‐hospital deaths when RA was a nonprimary diagnosis, the most common primary diagnosis was pneumonia (12.5 %) in 2000, whereas sepsis accounted for the most deaths in 2014 (31.4%).

Conclusion

We observed that hospitalization rates and in‐hospital mortality rates in patients with RA have changed significantly over the past 15 years.

Clinical Outcomes of Patients with Rheumatoid Arthritis Treated in a Disease Management Program: Real-World Results

Background

Care models can affect the clinical outcome of patients with rheumatic and musculoskeletal diseases.

Objective

We aimed to compare how an innovative model of a rheumatoid arthritis disease-management program can improve the clinical outcomes of patients compared to a conventional assessment approach.

Methods

We performed a retrospective analysis of real-world data from clinical records of a cohort of 5078 patients diagnosed with rheumatoid arthritis who were followed up at the Center of Excellence in Rheumatoid Arthritis vs the clinical outcomes reported in the Colombian National Registry of Rheumatoid Arthritis.

Results

We found significant differences in the diagnosis and follow-up between the specialized Center program and the usual care reported by the Colombian National Registry (p<0.005), including the evaluation of rheumatoid factor, Anti-citrullinated antibodies Disease Activity Score, Health Assessment Questionnaire, number of visits to the rheumatologist, and clinical outcomes measured by the level of disease activity. In addition, when comparing the Center's clinical outcomes - from baseline to the last follow-up, we found an improvement in the level of disease activity, with patients classified in remission increasing from 20.8% to 58.5% (p<0.005), and a reduction in those with high disease activity from 18% to 4.7% (p<0.005).

Conclusion

Real-world evidence showed that patients with rheumatoid arthritis who underwent follow-up under an innovative disease-management model improved their clinical outcomes compared with those patients in a conventional assessment program. These results could suggest a way of improving health policies for patients with rheumatoid arthritis.

Impact of Psychiatric Comorbidity on Health Care Use in Rheumatoid Arthritis: A Population-Based Study

Objective

Psychiatric comorbidity is frequent in rheumatoid arthritis (RA) and complicates treatment. The present study was undertaken to describe the impact of psychiatric comorbidity on health care use (utilization) in RA.

Methods

We accessed administrative health data (1984–2016) and identified a prevalent cohort with diagnosed RA. Cases of RA (n = 12,984) were matched for age, sex, and region of residence with 5 controls (CNT) per case (n = 64,510). Within each cohort, we identified psychiatric morbidities (depression, anxiety, bipolar disorder, and schizophrenia [PSYC]), with active PSYC defined as ≥2 visits per year. For the years 2006–2016, annual rates of ambulatory care visits (mean ± SD per person) categorized by provider (family physician [FP], rheumatologist, psychiatrist, other specialist), hospitalization (% of cohort), days of hospitalization (mean ± SD), and dispensed drug types (mean ± SD per person) were compared among 4 groups (CNT, CNT plus PSYC, RA, and RA plus PSYC) using generalized linear models adjusted for age, sex, rural versus urban residence, income quintile, and total comorbidities. Estimated rates are reported with 95% confidence intervals (95% CIs). We tested within‐person and RA‐PSYC interaction effects.

Results

Subjects with RA were mainly female (72%) and urban residents (59%), with a mean ± SD age of 54 ± 16 years. Compared to RA without PSYC, RA with PSYC had more than additive (synergistic) visits (standardized mean difference [SMD] 10.92 [95% CI 10.25, 11.58]), hospitalizations (SMD 13% [95% CI 0.11, 0.14]), and hospital days (SMD 3.63 [95% CI 3.06, 4.19]) and were dispensed 6.85 more medication types (95% CI 6.43, 7.27). Cases of RA plus PSYC had increased visits to FPs (an additional SMD 8.92 [95% CI 8.35, 9.46] visits). PSYC increased utilization in within‐person models.

Conclusion

Managing psychiatric comorbidity effectively may reduce utilization in RA.

Association between rainfall and readmissions of rheumatoid arthritis patients: a time-stratified case-crossover analysis

It has been reported that local weather is associated with the symptoms of joint pain in patients with rheumatoid arthritis (RA), and many people believe their pain becomes worse when facing rainy days. However, limited studies explored the effects of weather on RA patients' healthcare-seeking behavior. Our study aimed to investigate the relationship between rainfall and readmission behavior of patients with RA in Hefei, China, based on hospitalization data from the First Affiliated Hospital of Anhui University of Chinese Medicine from May 2012 to June 2016 and weather data from National Meteorological Information Center during the same study period. Using a time-stratified case-crossover study design and conditional logistic regression, we found a negative association between current day rainfall and readmission (unadjusted: OR = 0.82, p < 0.05; adjusted: OR = 0.83, p < 0.1), which is contrary to our common belief. In lagged models, we observed that rainfall was significantly and positively associated with readmissions at lag 6 days (unadjusted: OR = 1.12, p < 0.1; adjusted: OR = 1.17, p < 0.05) and lag 7 days (unadjusted: OR = 1.13, p < 0.05; adjusted: OR = 1.21, p < 0.01). Additionally, stratified analyses showed the unanticipated finding was only statistically significant for younger patients (< 65 years) and females. Our study adds new evidence that the association between the healthcare-seeking behavior of patients with RA and local rainfall may be different, compared with the positive relationship between symptoms of joint pain and rainfall.

Changing hospitalization trends for systemic lupus erythematosus and rheumatoid arthritis in England

OBJECTIVES

Systemic lupus erythematosus (SLE) is a chronic, multisystemic, immune-mediated disorder associated with a substantial hospitalization risk. As a comparatively rare disease, there is a sparsity of research examining the burden of hospital admission in the contemporary era. We aim to describe national trends in hospitalization rates in England between 1998 and 2015 for SLE, using rheumatoid arthritis (RA) and general population rates as comparison cohorts for benchmarking.

METHODS

Hospital admission rates, emergency and day-case admission rates, length of stay and bed days used were calculated using finished consultant episodes from Hospital Episode Statistics data. Cochran-Armitage tests and linear regression quantified the significance and magnitude of change over time.

RESULTS

SLE admissions increased from 8.97 to 9.04 per 100,000 (p < 0.001) between 1998 and 2015. By comparison, RA admissions rose from 71.0 to 171.6 per 100,000 (p < 0.001) and all-cause admissions rose from 24,500 to 34,500 per 100,000 (p < 0.001). Emergency admissions decreased both for SLE (2.6 to 1.2 per 100,000) and RA (12.8 to 4.4 per 100,000) despite all-cause emergency admissions increasing from 9400 to 10,300 per 100,000. SLE and RA day cases increased, whilst median length of stay decreased. Despite increasing admissions, total bed days for SLE and RA fell by 60% and 90%, respectively.

CONCLUSIONS

Whilst all-cause emergency admissions rose in the general population, those for SLE fell. Length of stay and bed days reduced and day cases increased, probably reflecting changing therapeutic strategies. This potentially large reduction in resource utilization warrants consideration when assessing the impact of new therapies.

Influence of disease duration and socioeconomic factors on the prevalence of infection and hospitalization in rheumatoid arthritis: KRAC study

AIM

The use of healthcare resources by rheumatoid arthritis (RA) patients can be related to the presence of disease, comorbid conditions, use of steroids, and the combined use of immunosuppressants. This study evaluated the risk factors associated with infection and hospitalization in RA.

METHODS

This multicenter, cross-sectional study enrolled 3247 RA subjects fulfilling the 2010 American College of Rheumatology/European League Against Rheumatism criteria to examine the prevalence of hospitalization and episodes of documentable non-tubercular infections as a part of the "Karnataka rheumatoid arthritis comorbidity" study (KRAC). The study included 2081 subjects and 1166 were excluded due to incomplete data. Demographic, clinical and treatment variables were collected, and the events related to infections and hospitalization were extracted from the medical records. Comparative analysis and multivariate logistic regression were performed.

RESULTS

Around 22% of the subjects had hospitalizations and 2.9% had infections. Infections were pertaining to dental (1.3%), urinary tract (1.6%) and candidiasis (0.2%). Skin- and soft tissue-related infections were found in 1.8% and 0.3% of patients, respectively. Increased need of hospitalization in RA patients was associated with advanced age (≥60 years), lower education, family income, and longer duration of RA. Presence of comorbidity, usage of three or more disease-modifying anti-rheumatic drugs (DMARDs) and family income influenced the likelihood of infection. Dental infections were less likely in working subjects and more likely in patients with increased disease duration, higher family income, comorbidities and those between the age group 40-59 years. Urinary tract infection was associated with DMARD usage.

CONCLUSION

Patient-specific risk factors should be considered to improve treatment strategies and to reduce the risk of infection and hospitalization in RA patients.

Physical comorbidities increase the risk of psychiatric comorbidity in immune-mediated inflammatory disease

OBJECTIVE

We tested the association between physical comorbidity and incident depression, anxiety disorder and bipolar disorder in three immune-mediated inflammatory diseases (IMID): inflammatory bowel disease (IBD), multiple sclerosis (MS) and rheumatoid arthritis (RA) versus age-, sex- and geographically-matched controls.

METHODS

Using population-based administrative data we identified 6119 persons with IBD, 3514 persons with MS, 10,206 persons with RA and 97,727 matched controls. We identified incident cases of depression, anxiety disorder and bipolar disorder in these populations. We evaluated the association of physical comorbidities with incident psychiatric comorbidity using Cox regression, adjusting for sociodemographic factors and index year.

RESULTS

The risk of incident depression, anxiety disorders and bipolar disorder was higher in each IMID cohort versus their matched cohorts. The risk of incident psychiatric comorbidity increased with an increasing number of physical comorbidities for each psychiatric comorbidity evaluated, across all IMID. Adjustment for physical comorbidity did not attenuate the increased risk of psychiatric comorbidity in the IMID cohorts versus their matched cohorts.

CONCLUSION

The increased incidence of psychiatric comorbidity in IMID versus matched general population cohorts is not accounted for by their increased prevalence of physical comorbidities. However, within IMID cohorts, physical comorbidity increases the risk of psychiatric comorbidity.

Hospitalisation rates among patients with primary Sjögren's syndrome: a population-based study, 1995-2016

OBJECTIVE

To determine rates and primary discharge diagnoses of hospitalisation in a cohort of patients with incident primary Sjögren's syndrome (pSS) compared with the general population.

METHODS

This was a retrospective population-based cohort study focused on Olmsted County, Minnesota. The pSS cohort consisted of patients with incident pSS in the 1976-2015 period and was compared with a cohort of individuals without pSS matched 3:1 for age, sex and calendar year, randomly selected from the same population. Hospitalisations in 1995-2016 were examined. Discharge diagnoses were categorised using the Clinical Classifications Software for International Classification of Diseases, 9th revision, Clinical Modification.

RESULTS

A total of 385 hospitalisations occurred in the 160 patients with pSS during 1592 person-years of follow-up. Among 466 comparators, there were 899 hospitalisations during 4660 person-years of follow-up, resulting in a significantly higher rate of hospitalisations in patients with pSS (rate ratio (RR): 1.25, 95% CI: 1.11 to 1.41). Rates of hospitalisation were increased among patients with pSS for endocrine, nutritional and metabolic diseases and immunity disorders (RR 1.82, 95% CI 1.08 to 2.98), diseases of the musculoskeletal system and connective tissue (RR 1.49, 95% CI 1.05 to 2.05) and for injuries and poisoning (RR 1.46, 95% CI 1.01 to 2.06). While not significantly increased overall, hospitalisations for diseases of the circulatory system were significantly increased in patients with pSS aged ≥75 years (RR 1.54, 95% CI 1.11 to 2.11).

CONCLUSIONS

Patients with pSS experienced higher rates of hospitalisation than the general population. Hospitalisations for endocrine/metabolic disorders, diseases of the circulatory system, diseases of the musculoskeletal system and connective tissue disorders, and injuries were more common among patients with pSS than comparators.

Development and validation of a multivariate predictive model for rheumatoid arthritis mortality using a machine learning approach

We developed and independently validated a rheumatoid arthritis (RA) mortality prediction model using the machine learning method Random Survival Forests (RSF). Two independent cohorts from Madrid (Spain) were used: the Hospital Clínico San Carlos RA Cohort (HCSC-RAC; training; 1,461 patients), and the Hospital Universitario de La Princesa Early Arthritis Register Longitudinal study (PEARL; validation; 280 patients). Demographic and clinical-related variables collected during the first two years after disease diagnosis were used. 148 and 21 patients from HCSC-RAC and PEARL died during a median follow-up time of 4.3 and 5.0 years, respectively. Age at diagnosis, median erythrocyte sedimentation rate, and number of hospital admissions showed the higher predictive capacity. Prediction errors in the training and validation cohorts were 0.187 and 0.233, respectively. A survival tree identified five mortality risk groups using the predicted ensemble mortality. After 1 and 7 years of follow-up, time-dependent specificity and sensitivity in the validation cohort were 0.79–0.80 and 0.43–0.48, respectively, using the cut-off value dividing the two lower risk categories. Calibration curves showed overestimation of the mortality risk in the validation cohort. In conclusion, we were able to develop a clinical prediction model for RA mortality using RSF, providing evidence for further work on external validation.

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.

Relationship between daily pain and affect in women with rheumatoid arthritis: lower optimism as a vulnerability factor

The aim of the study was to examine the moderating effect of optimism on the relationship between daily pain-daily affect. Fifty-four female patients with rheumatoid arthritis completed self-report measures of optimism (once), daily pain and daily positive and negative affect for 7 consecutive days during hospitalization. Results of multilevel random coefficients modeling demonstrated a significant cross-level interaction for daily negative affect only. Simple slopes analysis revealed that low optimism was related to a stronger positive relationship between daily pain and daily negative affect, whereas this effect was insignificant for higher optimism. High optimism was also related to higher daily positive affect, regardless of pain level. These findings suggest that low optimism may be a vulnerability factor in the daily pain-daily affect relationship rather than high optimism acting as a protective factor.