Rheumatoid Arthritis Disease Severity Indices in Administrative Databases: A Systematic Review

Do Patterns of Early Disease Severity Predict Grade 12 Academic Achievement in Youths With Childhood-Onset Chronic Rheumatic Diseases?

OBJECTIVE

To test the association of early disease severity with grade 12 standards test performance in individuals with childhood-onset chronic rheumatic diseases (ChildCRDs), including juvenile arthritis and systemic autoimmune rheumatic diseases.

METHODS

We used linked provincial administrative data to identify patients with ChildCRDs born between 1979 and 1998 in Manitoba, Canada. Primary outcomes were Language and Arts Achievement Index (LAI) scores and Math Achievement Index (MAI) scores from grade 12 standards test results as well as enrollment data. The secondary outcome was enrollment in grade 12 by 17 years of age. Latent class trajectory analysis identified disease severity groups using physician visits following diagnosis. Multivariable linear regression tested the association of disease severity groups with LAI and MAI scores, and logistic regression tested the association of disease severity with age-appropriate enrollment, after adjusting for sociodemographic factors and psychiatric morbidities.

RESULTS

The study cohort included 541 patients, 70.1% of whom were female. A 3-class trajectory model provided the best fit; it classified 9.7% of patients as having severe disease, 54.5% as having moderate disease, and 35.8% as having mild disease. After covariate adjustment, severe disease was associated with poorer LAI and MAI scores but not with age-appropriate enrollment.

CONCLUSION

Among patients with ChildCRDs, those with severe disease performed more poorly on grade 12 standards tests, independent of sociodemographic and psychiatric risk factors. Clinicians should work with educators and policy makers to advocate for supports to improve educational outcomes of patients with ChildCRDs.

The impact of rehabilitation frequency on the risk of stroke in patients with rheumatoid arthritis

BACKGROUND

Patients with rheumatoid arthritis are at higher risk of developing stroke due to augmented systemic inflammation. While regular exercise has been shown to reduce inflammation in human subjects, the purpose of our study is to determine whether increased frequency of rehabilitation is protective against stroke or not.

METHODS

A total of 16,224 rheumatoid arthritis patients with a catastrophic illness certificate were identified in our database from 2000 to 2006, and 663 of them developed stroke before the end of 2013. After statistically matching for age, sex, and the time interval between the diagnosis of rheumatoid arthritis and stroke, 642 patients without stroke were identified as the control group. Analyses with Student's t test and Chi-square test were done to compare the clinical characteristics of patients with and without stroke, and logistic regression analysis was then performed to evaluate the odds ratio of stroke.

RESULTS

Higher odds ratio of stroke was revealed in patients with hypertension, diabetes mellitus, and moderate degree of rheumatoid arthritis disease severity. Furthermore, more than 40 rehabilitation sessions per year reduced the risk of developing stroke in patients with moderate disease severity.

CONCLUSIONS

Physical activities brought by more rehabilitation sessions are beneficial and should be encouraged in patients with rheumatoid arthritis, particularly for those with higher disease activity but not taking biologic agents.

Risk of Hospitalized Infection and Initiation of Abatacept Versus Tumor Necrosis Factor Inhibitors Among Patients With Rheumatoid Arthritis: A Propensity Score-Matched Cohort Study

OBJECTIVE

We aimed to evaluate the comparative risk of hospitalized infection among patients with rheumatoid arthritis (RA) who initiated abatacept versus a tumor necrosis factor inhibitor (TNFi).

METHODS

Using claims data from Truven MarketScan database (2006-2015), we identified patients with RA ages ≥18 years with ≥2 RA diagnoses who initiated treatment with abatacept or a TNFi. The primary outcome was a composite end point of any hospitalized infection. Secondary outcomes included bacterial infection, herpes zoster, and infections affecting different organ systems. We performed 1:1 propensity score (PS) matching between the groups in order to control for baseline confounders. We estimated incidence rates (IRs) and hazard ratios (HRs) with 95% confidence intervals (95% CIs) for hospitalized infection.

RESULTS

We identified 11,248 PS-matched pairs of patients who initiated treatment with abatacept and TNFi with a median age of 56 years (83% were women). The IR per 1,000 person-years for any hospitalized infection was 37 among patients who initiated treatment with abatacept and 47 in those who initiated treatment with TNFi. The HR for the risk of any hospitalized infection associated with abatacept versus TNFi was 0.78 (95% CI 0.64-0.95) and remained lower when compared to infliximab (HR 0.63 [95% CI 0.47-0.85]), while no significant difference was seen when compared to adalimumab and etanercept. The risk of secondary outcomes was lower for abatacept for pulmonary infections, and similar to TNFi for the remaining outcomes.

CONCLUSION

In this large cohort of patients with RA who initiated treatment with abatacept or TNFi as a first- or second-line biologic agent, we found a lower risk of hospitalized infection after initiating abatacept versus TNFi, which was driven mostly by infliximab.

Associations Between Methotrexate Use and the Risk of Cardiovascular Events in Patients with Elderly-onset Rheumatoid Arthritis

OBJECTIVE

We evaluated the associations between time-varying methotrexate (MTX) use and risk of cardiovascular events (CVE) in patients with rheumatoid arthritis (RA).

METHODS

We studied an inception cohort of 23,994 patients with RA diagnosed after their 65th birthday. Multivariable Cox regression models were fit to evaluate the associations between time-varying MTX use, controlling for other risk factors, and time to CVE. Alternative models assessed the cumulative duration of MTX use over the (1) first year, (2) previous year (recent use), and (3) entire duration of followup. We also assessed whether the strength of the association varied over time.

RESULTS

Over 115,453 patient-years (PY), 3294 (13.7%) patients experienced a CVE (28.5 events per 1000 PY; 95% CI 27.6-29.5). In the multivariable analyses, the model assessing time-varying continuous use in the most recent year yielded the best fit. Increasing recent MTX use was associated with lower CVE risks (HR 0.79 for continuous use vs no use in past 12 months, 95% CI 0.70-0.88; p < 0.0001). Greater MTX use in the first year after cohort entry was also protective (HR 0.84, 95% CI 0.72-0.96; p = 0.0048), but this effect decreased with increasing followup. In contrast, longer MTX use during the entire followup was not clearly associated with CVE risk (HR 0.98, 95% CI 0.95-1.01; p = 0.1441).

CONCLUSION

We observed about a 20% decrease in CVE associated with recent continuous MTX use. Greater MTX use in the first year of cohort entry also appeared to be important in the association between MTX and CVE risk.

Have the annual trends of total hip arthroplasty in rheumatoid arthritis patients decreased?

Background

Rheumatoid arthritis (RA) is characterized by chronic systemic and synovial inflammation, resulting in damage to both cartilage and bone. Medical treatment, which has increasingly relied upon disease modifying anti-rheumatic drugs (DMARDs), may fail to slow disease progression and limit joint damage, ultimately warranting surgical intervention. Up to 25% of RA patients will require lower extremity total joint arthroplasty. Though total hip arthroplasty (THA) is known to improve quality of life and functional measures, clarification is still required with respect to the impact of increased DMARD use on annual rates of THA. Thus, the purpose of this study was to evaluate: (I) the annual trends of THAs due to RA in the United States population; (II) the annual trends in the proportion of THAs due to RA in the United States.

Methods

This study utilized the Nationwide Inpatient Sample (NIS) to identify all patients who underwent THA between 2002 and 2013 (n=3,135,904). Then, THA patients who had a diagnosis of RA, which was defined by the International Classification of Disease 9^th revision diagnosis code 714.0, were identified. The incidence of THAs with a diagnosis of RA in the United States was calculated using the United States population as the denominator. Regression models were used to analyze the annual trends of RA in patients who underwent THA.

Results

Review of the database identified 90,487 patients who had a diagnosis of RA and underwent THA from 2002 to 2013. The annual prevalence of RA in those who underwent THA slightly decreased over the specified time period, with 28.7 per 1,000 THAs in 2002 and 28.6 per 1,000 THAs in 2013; however, this change was not statistically significant (R²=0.158, P=0.200).

Conclusions

The annual rates of THA among RA patients did not show any significant change between 2002 and 2013. DMARD use has decreased both disease progression and joint destruction, and DMARDs are now often utilized as primary treatment. The increase in population of the country during the study period may have overestimated THA trends. Moreover, patients may be more likely to opt for surgical management, given the advances in operative techniques as well as peri- and post-operative course.

Incidence and Prevalence of Cardiovascular Risk Factors Among Patients With Rheumatoid Arthritis, Psoriasis, or Psoriatic Arthritis

OBJECTIVE

To estimate prevalence and incidence of cardiovascular (CV) risk factors of hypertension, diabetes mellitus, hyperlipidemia, and obesity in patients with rheumatoid arthritis (RA), psoriasis, or psoriatic arthritis (PsA).

METHODS

Patients with RA, psoriasis, or PsA were identified based on medical and pharmacy claims from the MarketScan claims databases from January 1, 2002 through December 31, 2014. Primary outcomes included age- and sex-standardized prevalence of CV risk factors during the 12 months preceding diagnosis date and incidence rates per 1,000 patient-years, with 95% confidence intervals (95% CIs) during followup.

RESULTS

Prevalence for RA, psoriasis, and PsA cohorts for hypertension was 18.6% (95% CI 18.3-18.8), 16.6% (95% CI 16.3-17.0), and 19.9% (95% CI 19.4-20.4), respectively; for diabetes mellitus 6.2% (95% CI 6.1-6.4), 6.3% (95% CI 6.0-6.5), and 7.8% (95% CI 7.4-8.2); for hyperlipidemia 9.9% (95% CI 9.7-10.1), 10.4% (95% CI 10.2-10.7), and 11.6% (95% CI 11.2-12.0); and for obesity 4.4% (95% CI 4.2-4.6), 3.8% (95% CI 3.5-4.0), and 6.0% (95% CI 5.6-6.5). Incidence rates per 1,000 patient-years during followup for RA, psoriasis, and PsA cohorts, respectively, for hypertension were 74.0 (95% CI 72.5-75.5), 68.2 (95% CI 65.9-70.4), and 79.8 (95% CI 76.3-83.3); for diabetes mellitus 10.6 (95% CI 10.1-11.1), 13.0 (95% CI 12.1-13.8), and 14.7 (95% CI 13.5-16.0); for hyperlipidemia 40.3 (95% CI 39.4-41.3), 47.1 (95% CI 45.4-48.7), and 52.0 (95% CI 49.6-54.3); and for obesity 24.4 (95% CI 23.4-25.4), 26.4 (95% CI 25.0-27.8), and 32.9 (95% CI 30.6-35.2).

CONCLUSION

Patients with RA, psoriasis, and PsA have high prevalence and incidence of CV risk factors, suggesting the need for risk factor monitoring of these patients.

Severity indices in rheumatoid arthritis: A systematic review

OBJECTIVE

To identify tools designed to evaluate the severity of patients with rheumatoid arthritis (RA) in order to use them in the investigation of prognostic markers in early arthritis.

METHODS

We conducted a systematic review of studies that developed/validated an index for RA disease severity. They were analyzed using the COSMIN checklist to assess their methodological quality. In addition, all the variables included were evaluated for their clarity of definition, feasibility and probability of being present in each outcome during the first 2 years of the disease course. To estimate redundancy, variables were grouped by domains.

RESULTS

After reviewing 3,519 articles, 3 studies were included. The first study, the PAS, assessed whether current and lifetime treatment with disease-modifying antirheumatic drugs and/or biologics accurately predicted RA severity, as measured by the patient-reported PAS. Treatment variables did not fully distinguish patients in the highest and lowest quartiles of PAS scores. Another severity index, the Claims-Based Index for RA Severity (CIRAS), included the variables age, sex, Felty's syndrome, number of rehabilitation and rheumatology visits, test for inflammatory markers, number of chemistry panels/platelet counts ordered and rheumatoid factor test. The correlation was low (r=0.56) with an index previously validated by the same research group, the RA medical records-based index of severity (RARBIS), with Disease Activity Score-C-reactive protein (DAS28-PCR) (r=0.07) and Multidimensional Health Assessment Questionnaire (MD-HAQ) (r=0.008). Finally, the RARBIS, used to validate the CIRAS, was devised as an RA severity index based on medical records. It includes as domains surgery, radiology, extra-articular manifestations, clinical and laboratory variables, previously chosen by an expert panel. RARBIS had a weak correlation with treatment intensity (r=0.35) and with DAS28 (r=0.41).

CONCLUSION

There is no index to assess the severity of RA based on the course of the first 2 years of follow-up that is adapted to the current strategy of therapeutic management of this disease. Therefore, we believe it is reasonable to develop a new ad hoc severity index for patients with early arthritis.

Major involvement of bacterial components in rheumatoid arthritis and its accompanying oxidative stress, systemic inflammation and hypercoagulability

We review the evidence that infectious agents, including those that become dormant within the host, have a major role to play in much of the etiology of rheumatoid arthritis and the inflammation that is its hallmark. This occurs in particular because they can produce cross-reactive (auto-)antigens, as well as potent inflammagens such as lipopolysaccharide that can themselves catalyze further inflammagenesis, including via β-amyloid formation. A series of observables coexist in many chronic, inflammatory diseases as well as rheumatoid arthritis. They include iron dysregulation, hypercoagulability, anomalous morphologies of host erythrocytes, and microparticle formation. Iron dysregulation may be responsible for the periodic regrowth and resuscitation of the dormant bacteria, with concomitant inflammagen production. The present systems biology analysis benefits from the philosophical idea of "coherence," that reflects the principle that if a series of ostensibly unrelated findings are brought together into a self-consistent narrative, that narrative is thereby strengthened. As such, we provide a coherent and testable narrative for the major involvement of (often dormant) bacteria in rheumatoid arthritis.

The Longterm Effect of Early Intensive Treatment of Seniors with Rheumatoid Arthritis: A Comparison of 2 Population-based Cohort Studies on Time to Joint Replacement Surgery

OBJECTIVE

Disease-modifying antirheumatic drugs (DMARD) have the greatest effect when initiated early. We evaluated the influence of early exposure to DMARD on time to joint replacement surgery among patients with incident rheumatoid arthritis (RA).

METHOD

Using a common protocol, we undertook 2 independent population-based cohort studies of patients with incident RA aged 66 years or older in Ontario (ON) and Quebec (QC) covering the period 2000-2013. We used Cox proportional hazards regression with time-dependent variables measuring duration of drug use in the first year, separately for methotrexate (MTX) and other DMARD, adjusting for baseline demographics, clinical factors, and other potentially confounding drug exposures. Our outcome measure was any joint replacement derived from standardized procedure codes. Adjusted HR and 95% CI were estimated.

RESULTS

Among 20,918 ON and 6754 QC patients with RA followed for a median of 4.5 years, 2201 and 494 patients underwent joint replacement surgery for crude event rates of 2.0 and 1.4 per 100 person-years, respectively. Greater cumulative exposure to MTX (HR 0.97, 95% CI 0.95-0.98) and other DMARD (HR 0.98, 95% CI 0.97-0.99) in the first year after diagnosis was associated with longer times to joint replacement in ON, corresponding to a 2-3% decrease in the hazard of surgery with each additional month of early use. Similar results were observed in QC.

CONCLUSION

Greater duration of exposure to DMARD soon after RA diagnosis was associated with delays to joint replacement surgery in both provinces. Early intensive treatment of RA may ultimately reduce demand for joint replacement surgery.

Rheumatoid arthritis vs osteoarthritis in patients receiving total knee arthroplasty: perioperative outcomes

There is a paucity of data available on perioperative outcomes of patients undergoing total knee arthroplasty (TKA) for rheumatoid arthritis (RA). We determined differences in demographics and risk for perioperative adverse events between patients suffering from osteoarthritis (OA) versus RA using a population-based approach. Of 351,103 entries for patients who underwent TKA, 3.4% had a diagnosis of RA. RA patients were on average younger [RA: 64.3 years vs OA: 66.6 years; P<0.001] and more likely female [RA: 79.2% vs OA: 63.2%; P<0. 001]. The unadjusted rates of mortality and most major perioperative adverse events were similar in both groups, with the exception of infection [RA: 4.5% vs. OA: 3.8%; P<0.001]. RA was not associated with increased adjusted odds for combined adverse events.

Biologic disease-modifying anti-rheumatic drugs and the risk of non-vertebral osteoporotic fractures in patients with rheumatoid arthritis aged 50 years and over

Prevention of bone mineral density loss in rheumatoid arthritis (RA) has been associated with use of biologic disease-modifying anti-rheumatic drugs (DMARDs). However, in this study, we could not demonstrate a reduction in the risk of non-vertebral fractures. Additional research is required to clarify the impact of biologic DMARDs on fracture risk in RA.

INTRODUCTION

Small studies have suggested biologic DMARDs preserve bone mineral density at 6-12 months. Our objective was to determine the association between biologic DMARD use and the risk of non-vertebral osteoporotic fractures in RA subjects aged ≥50 years.

METHODS

A nested case-control study was conducted using Quebec physician billing and hospital discharge data. RA subjects were identified from International Classification of Disease-9/10 codes in billing and hospitalisation data and followed from cohort entry until the earliest of non-vertebral osteoporotic fracture, death, or end of study period. Controls were matched to cases (4:1 ratio) on age, sex, and date of cohort entry. Biologic DMARD exposure was defined as being on treatment for ≥180 days pre-fracture (index). Conditional logistic regression was used, adjusting for indicators of RA severity, comorbidity, drugs influencing fracture risk, and measures of health care utilisation.

RESULTS

Over the study period, 1,515 cases were identified (6,023 controls). The most frequent fracture site was hip/femur (42.3%). In total, 172 subjects (49 cases and 123 controls) were exposed to biologic DMARDs. The median duration of exposure was 735 (interquartile range (IQR), 564) and 645 (IQR, 903) days in cases and controls, respectively. We were unable to demonstrate an association between biologic DMARDs and fracture risk (odds ratio, 1.03; 95% confidence interval, 0.42-2.53). RA duration significantly increased the fracture risk.

CONCLUSIONS

Despite the positive impact of biologic DMARDs on bone remodelling observed in small studies, we were unable to demonstrate a reduction in the risk of non-vertebral osteoporotic fractures in older adults with RA.

Serious infections in a population-based cohort of 86,039 seniors with rheumatoid arthritis

OBJECTIVE

To assess risk and risk factors for serious infections in seniors with rheumatoid arthritis (RA) using a case-control study nested within an RA cohort.

METHODS

We assembled a retrospective RA cohort age ≥66 years from Ontario health administrative data across 1992-2010. Nested case-control analyses were done, comparing RA patients with a primary diagnosis of infection (based on hospital or emergency department records) to matched RA controls. We assessed independent effects of drugs, adjusting for demographics, comorbidity, and markers of RA severity.

RESULTS

A total of 86,039 seniors with RA experienced 20,575 infections, for a rate of 46.4 events/1,000 person-years. The most frequently occurring events included respiratory infections, herpes zoster, and skin/soft tissue infections. Factors associated with infection included higher comorbidity, rural residence, markers of disease severity, and history of previous infection. In addition, anti-tumor necrosis factor agents and disease-modifying antirheumatic drugs were associated with a several-fold increase in infections, with an adjusted odds ratio (OR) ranging from 1.2-3.5. The drug category with the greatest effect estimate was glucocorticoids, which exhibited a clear dose response with an OR ranging from 4.0 at low doses to 7.6 at high doses.

CONCLUSION

Seniors with RA have significant morbidity related to serious infections, which exceeds previous reports among younger RA populations. Rural residence, higher comorbidity, markers of disease severity, and previous infection were associated with serious infections in seniors with RA. Our results emphasize that many RA drugs may increase the risk of infection, but glucocorticoids appear to confer a particular risk.

Consensus statements for the use of administrative health data in rheumatic disease research and surveillance

OBJECTIVE

Administrative data are increasingly being used for research and surveillance about rheumatic diseases. However, literature reviews have revealed a lack of consistency in methods for conducting observational rheumatic disease studies, a situation that can lead to findings that cannot be compared. Our purpose was to develop best-practice consensus statements about the use of administrative data for rheumatic disease research and surveillance in Canada.

METHODS

We convened 52 decision makers, epidemiologists, clinicians, and researchers to a 2-day workshop. Prior to this, participants formed working groups to examine 3 best-practice categories: case definitions, epidemiology methods, and comorbidity and outcomes measurement. The groups conducted systematic or scoping reviews on key topics. At the workshop, evidence from the reviews was presented and consensus-building techniques were used to develop the best-practice statements. The statements were presented, discussed, revised (as needed), and then subjected to voting.

RESULTS

Thirteen best-practice consensus statements were developed and endorsed by consensus. For the first category, these consensus statements addressed validation techniques for rheumatic disease case definitions and case ascertainment bias. The consensus statements for epidemiology methods focused on confounding and drug exposure measurement. For comorbidity and outcomes measurement, consensus statements were developed for multiple conditions, including osteoporosis and fragility fractures, cancer, infections, cardiovascular disease, and renal disease. Strengths and limitations of administrative data were identified in relation to each topic.

CONCLUSION

Our best-practice consensus statements are consistent with other recent guidelines, including those for rheumatic disease biologics registries, but address additional issues specific to administrative data. Continuing work focuses on disseminating these consensus statements to multiple audiences.