Performance of Administrative Algorithms to Identify Interstitial Lung Disease in Rheumatoid Arthritis

Non-TNFi biologic and targeted synthetic DMARDs in rheumatoid arthritis-associated interstitial lung disease: A propensity score-matched, active-comparator, new-user study

OBJECTIVES

This study aimed to compare treatment outcomes in rheumatoid arthritis-associated interstitial lung disease (RA-ILD) between initiators of rituximab, abatacept, tocilizumab, and tofacitinib using the Target Trial Emulation Framework.

METHODS

We emulated three trials comparing abatacept, tocilizumab, and tofacitinib with rituximab (reference). Patients fulfilling validated RA-ILD algorithms initiating one of these non-TNFi b/tsDMARDs were propensity score (PS)-matched (1:1) using national Veterans Affairs (VA) data from 2006 to 2020. PS models included demographics, comorbidities, general health status indicators, and several RA- and ILD-related severity measures. Composite study outcomes were death and respiratory-related hospitalization, ascertained by VA data and linkages to the National Death Index and Medicare, over three-year (primary) and one-year follow-up periods (secondary). Cox regression models were used to analyze study outcomes adjusting for any unbalanced variables. Several sensitivity and subgroup analyses were performed.

RESULTS

In the primary cohort, we 1:1 matched abatacept (n = 150), tocilizumab (n = 73), and tofacitinib (n = 94) with equal numbers of rituximab initiators (mean age 68.1-69.4 years, 88-92 % male). There were no significant differences in the primary composite outcome among any of the comparisons (abatacept aHR: 1.03 [0.72, 1.47]; tocilizumab aHR: 1.15 [0.68, 1.93]; tofacitinib aHR: 0.89 [0.54, 1.46]). Secondary, subgroup, and sensitivity analyses supported the main findings.

CONCLUSIONS

We did not find significant differences in mortality or respiratory hospitalization between RA-ILD patients initiating different non-TNFi b/tsDMARDs, though estimates were imprecise, and residual confounding may be present. These findings emphasize the need for clinical trials of advanced immunomodulatory therapies in RA-ILD.

Advanced therapies in US veterans with rheumatoid arthritis-associated interstitial lung disease: a retrospective, active-comparator, new-user, cohort study

BACKGROUND

Uncertainty exists regarding patient outcomes when using TNF inhibitors versus other biological and targeted synthetic disease-modifying antirheumatic drugs (DMARDs) in rheumatoid arthritis-associated interstitial lung disease (ILD). We compared survival and respiratory hospitalisation outcomes following initiation of TNF-inhibitor or non-TNF inhibitor biological or targeted synthetic DMARDs for treatment of rheumatoid arthritis-associated ILD.

METHODS

We did a retrospective, active-comparator, new-user, observational cohort study with propensity score matching following the target trial emulation framework using US Department of Veterans Affairs (VA) electronic and administrative health records. VA health-care enrollees with rheumatoid arthritis-associated ILD and no previous receipt of ILD-directed therapies (eg, antifibrotics) who initiated a TNF inhibitor or non-TNF inhibitor between Jan 1, 2006, and Dec 31, 2018, were included. Propensity score matching was performed using demographics, health-care use, health behaviours, comorbidity burden, rheumatoid arthritis-related severity factors, and ILD-related severity factors, including baseline forced vital capacity. Study outcomes were respiratory hospitalisation, all-cause mortality, and respiratory-related death over follow-up of up to 3 years, from VA, Medicare, and National Death Index data. People with lived experience of rheumatoid arthritis-associated ILD were not involved in the design or conduct of this study.

FINDINGS

Of 1047 patients with rheumatoid arthritis-associated-ILD who initiated biological or targeted synthetic DMARDs, we matched 237 patients who had initiated TNF inhibitors and 237 who had initiated non-TNF inhibitors (mean age 68 years [SD 9]); 434 (92%) of 474 were male and 40 (8%) were female. Death and respiratory hospitalisation did not significantly differ between groups (adjusted hazard ratio 1·21 [95% CI 0·92-1·58]). Respiratory hospitalisation (1·27 [0·91-1·76]), all-cause mortality (1·15 [0·83-1·60]), and respiratory mortality (1·38 [0·79-2·42]) did not differ between groups. Secondary, sensitivity, and subgroup analyses supported the primary findings.

INTERPRETATION

In US veterans with rheumatoid arthritis-associated ILD, no difference in outcomes were seen between those who started TNF inhibitors compared to those starting non-TNF biological or targeted synthetic DMARDs. These data do not support systematic avoidance of TNF inhibitors in all people with rheumatoid arthritis-associated ILD. Comparative efficacy trials in patients with rheumatoid arthritis-associated ILD are needed given the potential for residual confounding and selection bias in observational studies.

FUNDING

US Department of Veterans Affairs.

The Veterans Affairs Rheumatoid Arthritis Registry: A unique population in rheumatoid arthritis research

BACKGROUND

As the largest integrated healthcare system in the U.S., the Veterans Affairs (VA) provides a unique context for the conduct of clinical and clinical-translational research in rheumatoid arthritis (RA).

OBJECTIVES

To review attributes of the VA Rheumatoid Arthritis Registry (RA) and highlight its research contributions.

FINDINGS

With >3,600 participants enrolled from 19 VA medical centers across the U.S., VARA includes longitudinally collected clinical data and a central biorepository that includes serum, plasma, and DNA collected at enrollment. VARA research capacity is enhanced via active linkages with internal data including the VA's Corporate Data Warehouse and elements captured during oncology care. This capacity is further enabled via active linkages with the National Death Index and Centers for Medicare & Medicaid Services (CMS) data.

CONCLUSION

As a highly unique study population with comprehensive data annotation available to researchers, VARA is poised to continue address impactful questions in RA for years to come.

The global prevalence of interstitial lung disease in patients with rheumatoid arthritis: a systematic review and meta-analysis

This study aims to review the literature and estimate the global pooled prevalence of interstitial lung disease among patients with rheumatoid arthritis (RA-ILD). The influence of risk factors like geography, socioeconomic status, smoking and DMARD use will be explored. A systematic review was performed according to the PRISMA and JBI guidelines. Studies published between January 1980 and February 2024 were sourced from 7 electronic databases and screened for eligibility. A random-effects meta-analysis model was used to produce pooled prevalences and the potential between-study heterogeneity was identified using sensitivity, subgroup, meta-regression and correlation analyses. 33 studies were included in this meta-analysis containing 14,281 RA patients. The global pooled prevalence of RA-ILD was 21.38% (CI: 0.1542-0.2886), with a high heterogeneity (I2) of 98%. The prevalence of usual interstitial pneumonia and non-specific interstitial pneumonia among RA patients were 11.01% and 6.86% respectively. Africa had the highest RA-ILD prevalence with an imprecise estimate of 38.15% (95% Confidence Interval [CI]: 2.29-94.2) and Europe had the lowest prevalence of 10.15% (CI: 2.86-30.23). Other risk factors associated with a higher prevalence of RA-ILD included living in low-income countries, smoking and DMARD use. The biggest limitation of this study is the high heterogeneity of results and underrepresentation of Oceania and low-income countries. This study has clarified the global prevalence of RA-ILD. The risk factors identified in this study can aid clinicians in identifying high-risk populations and highlight the need for screening these populations. Smoking cessation should also be encouraged.

Associations of Fire Smoke and Other Pollutants With Incident Rheumatoid Arthritis and Rheumatoid Arthritis-Associated Interstitial Lung Disease

OBJECTIVE

The aim of this study was to determine whether pollutants such as fire smoke-related particulate matter <2.5 μm (PM2.5) are associated with incident rheumatoid arthritis (RA) and RA-associated interstitial lung disease (RA-ILD).

METHODS

This patient-control study used Veterans Affairs (VA) data from October 1, 2009, to December 31, 2018. We identified patients with incident RA and RA-ILD using validated algorithms, matching each patient to ≤10 controls on age, sex, and VA enrollment year. We obtained pollutants including fire smoke PM2.5, carbon monoxide, nitrogen oxides (NOx), ozone, overall PM2.5, PM10, and sulfur dioxide (SO2) at least one year before the index date. We fit conditional logistic regression models to estimate adjusted odds ratios (aORs) with 95% confidence intervals (CIs) for incident RA and RA-ILD, adjusted for confounders.

RESULTS

We identified 9,701 patients with incident RA (mean age 65 years, 86% male), including 531 patients with RA-ILD (mean age 69 years, 91% male), and 68,852 matched controls. Fire smoke PM2.5 was not associated with RA (aOR 1.07, 95% CI 0.92-1.23) but was associated with RA-ILD (aOR 1.98, 95% CI 1.08-3.62, per 1 μg/m3). Increased levels of NOx were associated with RA (aOR 1.16, 95% CI 1.06-1.27, highest vs lowest quartile). The highest quartiles of ozone (aOR 1.19, 95% CI 1.06-1.34) and PM10 (aOR 1.25, 95% CI 1.10-1.43) were associated with seronegative RA. Carbon monoxide, overall PM2.5, and SO2 were not, or negatively, associated with RA and RA-ILD.

CONCLUSION

Increased fire smoke PM2.5 was associated with RA-ILD, whereas NOx, ozone, and PM10 were associated with RA risk. Thus, air pollution may increase the risk of RA and RA-ILD.

Development and internal validation of a clinical and genetic risk score for rheumatoid arthritis-associated interstitial lung disease

OBJECTIVE

Although clinical and genetic risk factors have been identified for rheumatoid arthritis-associated interstitial lung disease (RA-ILD), there are no current tools allowing for risk stratification. We sought to develop and validate an ILD risk model in a large, multicentre, prospective RA cohort.

METHODS

Participants in the Veterans Affairs RA (VARA) registry were genotyped for 12 single nucleotide polymorphisms (SNPs) associated with idiopathic pulmonary fibrosis. ILD was validated through systematic record review. A genetic risk score (GRS) was computed from minor alleles weighted by effect size with ILD, using backward selection. The GRS was combined with clinical risk factors within a logistic regression model. Internal validation was completed using bootstrapping, and model performance was assessed by the area under the receiver operating curve (AUC).

RESULTS

Of 2386 participants (89% male, mean age 69.5 years), 9.4% had ILD. Following backward selection, five SNPs contributed to the GRS. The GRS and clinical factors outperformed clinical factors alone in discriminating ILD (AUC 0.675 vs 0.635, P < 0.001). The shrinkage-corrected performance for combined and clinical-only models was 0.667 (95% CI 0.628, 0.712) and 0.623 (95% CI 0.584, 0.651), respectively. Twenty percent of the cohort had a combined risk score below a cut-point with >90% sensitivity.

CONCLUSION

A clinical and genetic risk model discriminated ILD in a large, multicentre RA cohort better than a clinical-only model, excluding 20% of the cohort from low-yield testing. These results demonstrate the potential utility of a GRS in RA-ILD and support further investigation into individualized risk stratification and screening.

Rheumatoid Arthritis-Associated Interstitial Lung Disease (RA-ILD): Update on Prevalence, Risk Factors, Pathogenesis, and Therapy

PURPOSE OF REVIEW

Rheumatoid arthritis is frequently complicated by interstitial lung disease (RA-ILD), an underappreciated contributor to excess morbidity and mortality. The true prevalence of RA-ILD is difficult to define given the variability in diagnostic criteria used. The lack of standardized screening methods, an incomplete understanding of disease pathogenesis, and dearth of validated biomarkers have limited the development of controlled clinical trials for this disease.

RECENT FINDINGS

Numerous studies have focused on clinical, radiographic, genetic, molecular, and/or serologic markers of disease severity as well as risk of disease progression. In addition to defining valuable clinical biomarkers, these studies have provided insights regarding the pathogenesis of RA-ILD and potential therapeutic targets. Additional studies involving immunomodulatory and/or anti-fibrotic agents have assessed new therapeutic options for different stages of RA-ILD. RA-ILD continues to be a major contributor to the increased morbidity and mortality associated with RA. Advancements in our understanding of disease pathogenesis at a molecular level are necessary to drive the development of more targeted therapy.

The Risk of Lung Cancer in Rheumatoid Arthritis and Rheumatoid Arthritis-Associated Interstitial Lung Disease

OBJECTIVE

We aimed to evaluate lung cancer risk in patients with rheumatoid arthritis (RA) and RA-interstitial lung disease (ILD).

METHODS

We performed a retrospective, matched cohort study of RA and RA-ILD within the Veterans Health Administration (VA) between 2000 and 2019. Patients with RA and RA-ILD were identified with validated administrative-based algorithms, then matched (up to 1:10) on age, gender, and VA enrollment year to individuals without RA. Lung cancers were identified from a VA oncology database and the National Death Index. Conditional Cox regression models assessed lung cancer risk adjusting for race, ethnicity, smoking status, Agent Orange exposure, and comorbidity burden among matched individuals. Several sensitivity analyses were performed.

RESULTS

We matched 72,795 patients with RA with 633,937 patients without RA (mean age 63 years; 88% male). Over 4,481,323 patient-years, 17,099 incident lung cancers occurred. RA was independently associated with an increased lung cancer risk (adjusted hazard ratio [aHR] 1.58 [95% confidence interval (CI) 1.52-1.64]), which persisted in never smokers (aHR 1.65 [95% CI 1.22-2.24]) and in those with incident RA (aHR 1.54 [95% CI 1.44-1.65]). Compared to non-RA controls, prevalent RA-ILD (n = 757) was more strongly associated with lung cancer risk (aHR 3.25 [95% CI 2.13-4.95]) than RA without ILD (aHR 1.57 [95% CI 1.51-1.64]). Analyses of both prevalent and incident RA-ILD produced similar results (RA-ILD vs non-RA aHR 2.88 [95% CI 2.45-3.40]).

CONCLUSION

RA was associated with a >50% increased risk of lung cancer, and those with RA-ILD represented a particularly high-risk group with an approximate three-fold increased risk. Increased lung cancer surveillance in RA, and especially RA-ILD, may be a useful strategy for reducing the burden posed by the leading cause of cancer death.

MUC5B Promoter Variant and Survival in Rheumatoid Arthritis-Associated Interstitial Lung Disease

OBJECTIVE

Investigate the association between the MUC5B rs35705950 promoter variant and survival in RA-associated interstitial lung disease (RA-ILD).

METHODS

We studied participants in the Veteran Affairs Rheumatoid Arthritis (VARA) registry with validated ILD diagnoses. Participants were followed until death or end of study period. The MUC5B rs35705950 promoter variant was measured using an Infinium genotyping array, assuming autosomal dominant inheritance. Survival and cause of death were determined from VA death records and the National Death Index. Associations of the MUC5B promoter variant with survival were tested in Cox regression models adjusting for potential confounders.

RESULTS

Among 263 participants with RA-ILD (mean age 69 years, 95% male, 73% white race, 85% smoking history), the MUC5B promoter variant was present in 33.5%. Mortality rate was similar between those with (12.2/100PY [95% CI: 9.4, 15.8]) and without (11.1/100PY [95% CI: 9.1, 13.5]) the variant. MUC5B status was not significantly associated with survival overall (aHR 0.97 [95% CI: 0.68, 1.37]) or when stratified by ILD pattern (clinical usual interstitial pneumonia [UIP] aHR 0.86 [95% CI: 0.55, 1.35]; clinical non-UIP aHR 1.15 [95% CI: 0.63, 2.09]). Further, MUC5B status was not significantly associated with respiratory-related (aHR 0.83 [95% CI: 0.42, 1.66]) or non-respiratory causes of death (aHR 1.08 [95% CI: 0.72, 1.62]).

CONCLUSION

While associated with RA-ILD risk, the MUC5B promoter variant was not predictive of survival among RA-ILD patients in this multicentre cohort. Further studies are needed to identify other genetic and non-genetic prognostic factors in RA-ILD to inform disease management.

Antibodies to Malondialdehyde-Acetaldehyde Adduct Are Associated With Prevalent and Incident Rheumatoid Arthritis-Associated Interstitial Lung Disease in US Veterans

OBJECTIVE

The objective of this study is to determine the associations of protein-specific anti-malondialdehyde-acetaldehyde (MAA) antibodies with prevalent and incident rheumatoid arthritis-interstitial lung disease (RA-ILD).

METHODS

Within a multicenter, prospective cohort of US veterans with RA, RA-ILD was validated by medical record review of clinical diagnoses, chest imaging, and pathology. Serum antibodies to MAA-albumin, MAA-collagen, MAA-fibrinogen, and MAA-vimentin (IgA, IgM, and IgG) were measured by a standardized enzyme-linked immunosorbent assay. Associations of anti-MAA antibodies with prevalent and incident RA-ILD were assessed using multivariable regression models adjusting for established RA-ILD risk factors.

RESULTS

Among 2,739 participants with RA (88% male, mean age of 64 years), there were 114 with prevalent and 136 with incident RA-ILD (average time to diagnosis: 6.6 years). Higher IgM anti-MAA-collagen (per 1 SD: adjusted odds ratio [aOR] 1.28, 95% confidence interval [CI] 1.02-1.61), IgA anti-MAA-fibrinogen (aOR 1.48, 95% CI 1.14-1.92), and IgA (aOR 1.78, 95% CI 1.34-2.37) and IgG (aOR 1.48, 95% CI 1.14-1.92) anti-MAA-vimentin antibodies were associated with prevalent RA-ILD. In incident analyses, higher IgA (per one SD: adjusted hazards ratio [aHR] 1.40, 95% CI 1.11-1.76) and IgM (aHR 1.29, 95% CI 1.04-1.60) anti-MAA-albumin antibody concentrations were associated with increased ILD risk. Participants with IgA (aHR 2.13, 95% CI 1.16-3.90) or IgM (aHR 1.98, 95% CI 1.08-3.64) anti-MAA-albumin antibody concentrations in the highest quartile had an approximately two-fold increased risk of incident RA-ILD. Across all isotypes, anti-MAA-fibrinogen, anti-MAA-collagen, and anti-MAA-vimentin antibodies were not significantly associated with incident RA-ILD.

CONCLUSION

Protein-specific anti-MAA antibodies to collagen, fibrinogen, and vimentin were associated with prevalent RA-ILD. IgA and IgM anti-MAA-albumin antibodies were associated with a higher risk of incident RA-ILD. These findings suggest that MAA modifications and resultant immune responses may contribute to RA-ILD pathogenesis.

Exploring rheumatoid arthritis associated interstitial lung disease a retrospective study from two Saudi tertiary care centers

BACKGROUND

Interstitial lung disease (ILD) is an increasingly recognized complication of rheumatoid arthritis (RA) and is associated with significant morbidity and mortality. Many risk factors for RA-related ILD were reported. The current study aims to explore the features and risk factors of Saudi patients with RA-ILD.

METHODS

This is a multicenter, retrospective, observational study of patients with RA-ILD. Clinical and radiological data from patients with RA-ILD were obtained from electronic medical records, including demographics, clinical characteristics, laboratory tests, pulmonary function tests, ECHO, and HRCT images.

RESULT

Out of 732 patients, 57 had RA-ILD. The mean age at the time of ILD diagnosis was 61.9 (± 12.2) years. RA-ILD diagnosis was significantly less among females (p = 0.008). Patients who ever smoked had significantly more RA-ILD (p < 0.001). Patients with RA-ILD were more likely to present with medical comorbidities, namely diabetes (p < 0.001), hypertension (p < 0.001), ischemic heart disease (p < 0.001), and osteoarthritis (p = 0.030). The multivariate analysis revealed that the age (OR: 1.035, 95% CI: 48.45-52.86, p = 0.0001); gender (OR: 2.581, CI: 1.77-1.86, p = 0.001), DM (OR: 2.498, 95% Cl: 1.65-1.76, P = 0.0001), HTN (OR: 1.975, 95% Cl: 1.61-1.74, P = 0.019), IHD (OR: 6.043, 95% Cl: 1.89-1.93, P = 0.0001) have a significant positive association with RA-ILD. No significant differences were observed between seropositive parameters with or without RA-ILD (p > 0.05). The most common symptoms of RA-ILD were cough (55.6%) and dyspnea (30.2%), and the most common ILD pattern was Non-specific Interstitial Pneumonia (NSIP) (55.6%) followed by Usual Interstitial Pneumonia (UIP) (38.9%). Traction bronchiectasis (75.5%) and glass ground opacities (73.6%) were also observed. The mean FVC and DLCO at baseline were 64.6% and 53.3%, respectively.

CONCLUSION

In this cohort of patients, Saudi RA-ILD patients had a predominant NSIP pattern conversely to what is seen globally. These findings could be explained by the lower rates of smoking in our patient population. Future prospective national studies are needed to confirm the current findings and better evaluate RA-ILD epidemiology and risk factors.

Serum alarmins and the risk of incident interstitial lung disease in rheumatoid arthritis

OBJECTIVES

To quantify associations of serum alarmins with risk of rheumatoid arthritis-associated interstitial lung disease (RA-ILD).

METHODS

Using serum collected at enrolment, three alarmins (IL-33, thymic stromal lymphopoietin [TSLP] and IL-25) were measured in a multicentre prospective RA cohort. ILD was classified using systematic medical record review. Cross-sectional associations of log-transformed (IL-33, TSLP) or quartile (IL-25) values with RA-ILD at enrolment (prevalent RA-ILD) were examined using logistic regression, while associations with incident RA-ILD developing after enrolment were examined using Cox proportional hazards. Covariates in multivariate models included age, sex, race, smoking status, RA disease activity score and anti-cyclic citrullinated antibody positivity.

RESULTS

Of 2835 study participants, 115 participants (4.1%) had prevalent RA-ILD at baseline and an additional 146 (5.1%) developed incident ILD. There were no associations between serum alarmin concentrations and prevalent ILD in unadjusted or adjusted logistic regression models. In contrast, there was a significant inverse association between IL-33 concentration and the risk of developing incident RA-ILD in unadjusted (hazard ratio [HR] 0.73 per log-fold increase; 95% CI: 0.57, 0.95; P = 0.018) and adjusted (HR 0.77; 95% CI: 0.59, 1.00; P = 0.047) models. No significant associations of TSLP or IL-25 with incident ILD were observed.

CONCLUSION

In this study, we observed a significant inverse association between serum IL-33 concentration and the risk of developing incident RA-ILD, but no associations with prevalent ILD. Additional investigation is required to better understand the mechanisms driving this relationship and how serum alarmin IL-33 assessment might contribute to clinical risk stratification in patients with RA.

A validation of register-derived diagnoses of interstitial lung disease in patients with inflammatory arthritis: data from the NOR-DMARD study

OBJECTIVE

There is a lack of knowledge concerning the validity of the interstitial lung disease (ILD) diagnoses used in epidemiological studies on rheumatic diseases. This paper seeks to verify register-derived ILD diagnoses using chest computed tomography (CT) and medical records as a gold standard.

METHOD

The Norwegian Anti-Rheumatic Drug Register (NOR-DMARD) is a multicentre prospective observational study of patients with inflammatory arthritis who start treatment with disease-modifying anti-rheumatic drugs. NOR-DMARD is linked to the Norwegian Patient Registry (NPR) and Cause of Death Registry. We searched registers for ILD coded by ICD-10 J84 or J99 among patients with rheumatoid arthritis, psoriatic arthritis, or spondyloarthritis. We extracted chest CT reports and medical records from participating hospitals. Two expert thoracic radiologists scored examinations to confirm the ILD diagnosis. We also searched medical records to find justifications for the diagnosis following multidisciplinary evaluations. We calculated the positive predictive values (PPVs) for ILD across subsets.

RESULTS

We identified 71 cases with an ILD diagnosis. CT examinations were available in 65/71 patients (91.5%), of whom ILD was confirmed on CT in 29/65 (44.6%). In a further 10 patients, medical records confirmed the diagnosis, giving a total of 39/71 verified cases. The PPV of a register-derived ILD diagnosis was thus 54.9%. In a subset of patients who had received an ILD code at two or more time-points and had a CT scan taken within a relevant period, the PPV was 72.2%.

CONCLUSION

The validity of register-based diagnoses of ILD must be carefully considered in epidemiological studies.

Extracting forced vital capacity from the electronic health record through natural language processing in rheumatoid arthritis-associated interstitial lung disease

PURPOSE

To develop a natural language processing (NLP) tool to extract forced vital capacity (FVC) values from electronic health record (EHR) notes in patients with rheumatoid arthritis-interstitial lung disease (RA-ILD).

METHODS

We selected RA-ILD patients (n = 7485) in the Veterans Health Administration (VA) between 2000 and 2020 using validated ICD-9/10 codes. We identified numeric values in proximity to FVC string patterns from clinical notes in the EHR. Subsequently, we performed processing steps to account for variability in note structure, related pulmonary function test (PFT) output, and values copied across notes, then assigned dates from linked administrative procedure records. NLP-derived FVC values were compared to values recorded directly from PFT equipment available on a subset of patients.

RESULTS

We identified 5911 FVC values (n = 1844 patients) from PFT equipment and 15 383 values (n = 4982 patients) by NLP. Among 2610 date-matched FVC values from NLP and PFT equipment, 95.8% of values were within 5% predicted. The mean (SD) difference was 0.09% (5.9), and values strongly correlated (r = 0.94, p < 0.001), with a precision of 0.87 (95% CI 0.86, 0.88). NLP captured more patients with longitudinal FVC values (n = 3069 vs. n = 1164). Mean (SD) change in FVC %-predicted per year was similar between sources (-1.5 [30.0] NLP vs. -0.9 [16.6] PFT equipment; standardized response mean = 0.05 for both).

CONCLUSIONS

NLP of EHR notes increases the capture of accurate, longitudinal FVC values by three-fold over PFT equipment. Use of this NLP tool can facilitate pharmacoepidemiologic research in RA-ILD and other lung diseases by capturing this critical measure of disease severity.

Incidence and prevalence, and medication use among adults living with dermatomyositis: an Alberta, Canada population-based cohort study

Dermatomyositis is a rare disease characterized by progressive muscle weakness and skin rashes. Estimates of incidence and prevalence are fundamental measures in epidemiology, but few studies have been conducted on dermatomyositis. To address this knowledge gap, we conducted a population-based study to determine the contemporary incidence (between 2013 and 2019) and prevalence (2019) of adults living with dermatomyositis using administrative health data in Alberta, Canada. We also described disease-related medication use, as there are very few approved medications for the treatment of dermatomyositis, and no Canadian therapeutic guidelines. The average age- and sex-standardized annual incidence of dermatomyositis was 2.8-3.0 cases per 100,000 adults, and prevalence was 28.6 cases per 100,000 adults, which is greater than reported in other cohorts. Dermatomyositis-related medication use decreased from 73% in the first year to 46% in the eighth year after diagnosis. Glucocorticoids were the most commonly used drug class, often taken concurrently with various immunomodulatory agents; this medication use aligns with empirically-based recommendations and the few therapeutic guidelines for dermatomyositis. Considering that Alberta may have one of the highest rates of dermatomyositis among adults, further research on the burden of disease is warranted for planning within the health care system.

A Narrowing Mortality Gap: Temporal Trends of Cause-Specific Mortality in a National Matched Cohort Study in US Veterans With Rheumatoid Arthritis

OBJECTIVE

To examine temporal trends in all-cause and cause-specific mortality in patients with rheumatoid arthritis (RA) in the Veterans Health Administration (VHA).

METHODS

We conducted a matched cohort study in the VHA from January 1, 2000 to December 31, 2017. Incident RA patients were matched up to 1:10 on age, sex, and VHA enrollment year to non-RA patients, then followed until death or end of study period. Cause of death was obtained from the National Death Index. Multivariable Cox regression models stratified by RA diagnosis years were used to examine trends in RA-related risk of all-cause and cause-specific mortality.

RESULTS

Among 29,779 incident RA patients (matched to 245,226 non-RA patients), 9,565 deaths occurred. RA patients were at increased risk of all-cause (adjusted hazard ratio [HRadj ] 1.23 [95% confidence interval (95% CI) 1.20-1.26]), cardiovascular (HRadj 1.19 [95% CI 1.14-1.23]), cancer (HRadj 1.19 [95% CI 1.14-1.24]), respiratory (HRadj 1.46 [95% CI 1.38-1.55]), and infection-related mortality (HRadj 1.59 [95% CI 1.41-1.80]). Interstitial lung disease was the cause of death most strongly associated with RA (HRadj 3.39 [95% CI 2.88-3.99]). Nearly 70% of excess deaths in RA were attributable to cardiopulmonary disease. All-cause mortality risk related to RA was lower among those diagnosed during 2012-2017 (HRadj 1.10 [95% CI 1.05-1.15]) compared to 2000-2005 (HRadj 1.31 [95% CI 1.26-1.36]), but still higher than for non-RA controls (P < 0.001). Cause-specific mortality trends were similar.

CONCLUSION

Excess RA-related mortality was driven by cardiovascular, cancer, respiratory, and infectious causes, particularly cardiopulmonary diseases. Although our findings support that RA-related mortality risk is decreasing over time, a mortality gap remains for all-cause and cause-specific mortality in RA.

Enhancing the identification of rheumatoid arthritis-associated interstitial lung disease through text mining of chest computerized tomography reports

OBJECTIVES

Algorithms have been developed to identify rheumatoid arthritis-interstitial lung disease (RA-ILD) in administrative data with positive predictive values (PPVs) between 70 and 80%. We hypothesized that including ILD-related terms identified within chest computed tomography (CT) reports through text mining would improve the PPV of these algorithms in this cross-sectional study.

METHODS

We identified a derivation cohort of possible RA-ILD cases (n = 114) using electronic health record data from a large academic medical center and performed medical record review to validate diagnoses (reference standard). ILD-related terms (e.g., ground glass, honeycomb) were identified in chest CT reports by natural language processing. Administrative algorithms including diagnostic and procedural codes as well as specialty were applied to the cohort both with and without the requirement for ILD-related terms from CT reports. We subsequently analyzed similar algorithms in an external validation cohort of 536 participants with RA.

RESULTS

The addition of ILD-related terms to RA-ILD administrative algorithms increased the PPV in both the derivation (improvement ranging from 3.6 to 11.7%) and validation cohorts (improvement 6.0 to 21.1%). This increase was greatest for less stringent algorithms. Administrative algorithms including ILD-related terms from CT reports exceeded a PPV of 90% (maximum 94.6% derivation cohort). Increases in PPV were accompanied by a decline in sensitivity (validation cohort -3.9 to -19.5%).

CONCLUSIONS

The addition of ILD-related terms identified by text mining from chest CT reports led to improvements in the PPV of RA-ILD algorithms. With high PPVs, use of these algorithms in large data sets could facilitate epidemiologic and comparative effectiveness research in RA-ILD.

Genetic, social, and environmental risk factors in rheumatoid arthritis-associated interstitial lung disease

OBJECTIVE

MUC5B and TOLLIP single nucleotide polymorphisms (SNPs) and cigarette smoking were associated with rheumatoid arthritis-interstitial lung disease (RA-ILD) in a predominantly Northern European population. We evaluated whether RA-ILD is associated with these genetic variants and HLA-DRB1 shared epitope (SE) alleles in a large RA cohort stratified by race and smoking history.

METHODS

HLA-DRB1 SE alleles and MUC5B rs35705950 and TOLLIP rs5743890 SNPs were genotyped in U.S. veterans with RA. ILD was validated through medical record review. Genetic associations with ILD were assessed in logistic regression models overall and in subgroups defined by race and smoking status, with additive interactions assessed by the relative excess risk of interaction (RERI).

RESULTS

Of 2,556 participants (88% male, 77% White), 238 (9.3%) had ILD. The MUC5B variant was associated with ILD (OR 2.25 [95% CI 1.69, 3.02]), whereas TOLLIP and HLA-DRB1 SE were not. The MUC5B variant was less frequent among Black/African American participants (5.8% vs. 22.6%), though its association with RA-ILD was numerically stronger (OR 4.23 [1.65, 10.86]) compared to all other participants (OR 2.32 [1.70, 3.16]). Those with the MUC5B variant and a smoking history had numerically higher odds of ILD (OR 4.18 [2.53, 6.93]) than non-smokers (OR 2.41 [1.16, 5.04]). Additive interactions between MUC5B-race and MUC5B-smoking were not statistically significant.

CONCLUSION

In this large RA cohort, the MUC5B promoter variant was associated with >2-fold higher odds of RA-ILD. While this variant is less common among Black/African American patients, its presence in this population carried >4-fold higher odds of RA-ILD.

The impact of disease severity measures on survival in U.S. veterans with rheumatoid arthritis-associated interstitial lung disease

OBJECTIVES

To determine whether RA and interstitial lung disease (ILD) severity measures are associated with survival in patients with RA-ILD.

METHODS

We studied US veterans with RA-ILD participating in a multicentre, prospective RA cohort study. RA disease activity (28-joint DAS [DAS28-ESR]) and functional status (multidimensional HAQ [MDHAQ]) were collected longitudinally while pulmonary function tests (forced vital capacity [FVC], diffusing capacity for carbon monoxide) were obtained from medical records. Vital status and cause of death were determined from the National Death Index and administrative data. Predictors of death were assessed using multivariable Cox regression models adjusting for age, sex, smoking status, ILD duration, comorbidity burden and medications.

RESULTS

We followed 227 RA-ILD participants (93% male and mean age of 69 years) over 1073 person-years. Median survival after RA-ILD diagnosis was 8.5 years. Respiratory diseases (28%) were the leading cause of death, with ILD accounting for 58% of respiratory deaths. Time-varying DAS28-ESR (adjusted hazard ratio [aHR] 1.21; 95% CI: 1.03, 1.41) and MDHAQ (aHR 1.85; 95% CI: 1.29, 2.65) were separately associated with mortality independent of FVC and other confounders. Modelled together, the presence of either uncontrolled disease activity (moderate/high DAS28-ESR) or FVC impairment (<80% predicted) was significantly associated with mortality risk. Those with a combination of moderate/high disease activity and FVC <80% predicted had the highest risk of death (aHR 4.43; 95% CI: 1.70, 11.55).

CONCLUSION

Both RA and ILD disease severity measures are independent predictors of survival in RA-ILD. These findings demonstrate the prognostic value of monitoring the systemic features of RA-ILD.

Validation of an algorithm to identify incident interstitial lung disease in patients with rheumatoid arthritis

Background/purpose

Interstitial lung disease (ILD) is an important problem for patients with rheumatoid arthritis (RA). However, current approaches to ILD case finding in real-world data have been evaluated only in limited settings and identify only prevalent ILD and not new-onset disease. Our objective was to develop, refine, and validate a claims-based algorithm to identify both prevalent and incident ILD in RA patients compared to the gold standard of medical record review.

Methods

We used administrative claims data 2006–2015 from Medicare to derive a cohort of RA patients. We then identified suspected ILD using variations of ILD algorithms to classify both prevalent and incident ILD based on features of the data that included hospitalization vs. outpatient setting, physician specialty, pulmonary-related diagnosis codes, and exclusions for potentially mimicking pulmonary conditions. Positive predictive values (PPV) of several ILD algorithm variants for both prevalent and incident ILD were evaluated.

Results

We identified 234 linkable RA patients with sufficient data to evaluate for ILD. Overall, 108 (46.2%) of suspected cases were confirmed as ILD. Most cases (64%) were diagnosed in the outpatient setting. The best performing algorithm for prevalent ILD had a PPV of 77% (95% CI 67–84%) and for incident ILD was 96% (95% CI 85–100%).

Conclusion

Case finding in administrative data for both prevalent and incident interstitial lung disease in RA patients is feasible and has reasonable accuracy to support population-based research and real-world evidence generation.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13075-021-02655-z.

Autoantibody Seropositivity and Risk for Interstitial Lung Disease in a Prospective Male-Predominant Rheumatoid Arthritis Cohort of U.S. Veterans

Rationale: Prior studies investigating associations of rheumatoid factor (RF) and anti-citrullinated protein antibody (ACPA) seropositivity with risk for rheumatoid arthritis (RA)-associated interstitial lung disease (ILD) have mostly used cross-sectional or case-control designs.Objectives: To determine whether combined autoantibody seropositivity and higher individual autoantibody concentrations were associated with increased risk for RA-ILD in a prospective RA cohort.Methods: Within the Veterans Affairs Rheumatoid Arthritis prospective registry, we performed a cross-sectional study of prevalent ILD and a retrospective cohort study of incident ILD (diagnosed after at least 12 mo of longitudinal follow-up). We used logistic and Cox regression methods to determine whether combined RF/ACPA seropositivity and higher autoantibody concentrations were independently associated with greater risk for prevalent and incident ILD, respectively.Results: Among 2,328 participants (median age 64 yr, 89.3% male), 100 (4.3%) subjects had prevalent ILD at enrollment. During 14,281 patient-years of follow-up, 83 (3.7%) of the remaining 2,228 were subsequently diagnosed with incident ILD (5.8 cases per 1,000 person-years). Patients with combined RF/ACPA seropositivity had a higher probability of prevalent ILD compared with seronegative subjects (odds ratio [OR], 2.90; 95% confidence interval [CI], 1.24-6.78). RF titers demonstrated a monotonic association with prevalent ILD (OR, 2.69; 95% CI, 1.11-6.51 for low-positive [15-45 IU/ml] titers; OR, 3.40; 95% CI, 1.61-7.18 for high-positive [>45 IU/ml] titers; P for trend 0.01). Patients with high-positive (>15 U/ml) ACPA titers were also at higher risk for prevalent ILD (OR, 1.91; 95% CI, 1.04-3.49) compared with ACPA-negative subjects. Combined RF/ACPA seropositivity was not associated with increased risk for incident ILD, nor were high- or low-positive RF or ACPA titers. In a piecewise linear spline model, however, RF titers greater than 90 IU/ml independently correlated with increased risk for incident ILD (hazard ratio, 1.68, 95% CI, 1.02-2.77).Conclusions: Combined RF/ACPA seropositivity and individual autoantibody concentrations were strongly associated with prevalent but not incident RA-ILD. Only patients with RF concentrations >90 IU/ml were observed to be at higher risk of incident RA-ILD.

Association of Agricultural, Occupational, and Military Inhalants With Autoantibodies and Disease Features in US Veterans With Rheumatoid Arthritis

OBJECTIVE

To determine the association of inhalant exposures with rheumatoid arthritis (RA)-related autoantibodies and severity in US veterans.

METHODS

Participants in the Veterans Affairs Rheumatoid Arthritis (VARA) registry were mailed surveys assessing occupational, agricultural, and military inhalant exposures. Demographic characteristics, disease activity, functional status, and extraarticular features were obtained from the VARA registry, while HLA-DRB1 shared epitope (SE) status, anti-cyclic citrullinated peptide (anti-CCP) antibodies, and rheumatoid factor (RF) were measured using banked DNA/serum from enrollment. Associations between inhalant exposures and RA-related factors (autoantibodies, severity, and extraarticular features) were assessed using multivariable linear and logistic regression models adjusted for age, sex, race, and tobacco use and stratified by SE status. Adjusted odds ratios (ORs) and 95% confidence intervals (95% CIs) were calculated.

RESULTS

Questionnaires were returned by 797 of 1,566 participants (50.9%). Survey respondents were older, more often White or male, and less frequently smokers, and had lower disease activity compared to nonrespondents. Anti-CCP positivity was more common among veterans exposed to burn pits (OR 1.66 [95% CI 1.02, 2.69]) and military waste disposal (OR 1.74 [95% CI 1.04, 2.93]) independent of other factors. Among participants who were positive for SE alleles, burn pit exposure (OR 5.69 [95% CI 2.73, 11.87]) and military waste disposal exposure (OR 5.05 [95% CI 2.42, 10.54]) were numerically more strongly associated with anti-CCP positivity. Several inhalant exposures were associated with the presence of chronic lung disease, but not with the presence of RF or the level of disease activity.

CONCLUSION

Military burn pit exposure and military waste disposal exposure were independently associated with the presence of anti-CCP antibodies in RA patients. These findings are consistent with emerging evidence that various inhalant exposures influence autoantibody expression and RA risk.

Rheumatoid arthritis-related lung disease detected on clinical chest computed tomography imaging: Prevalence, risk factors, and impact on mortality

OBJECTIVE

We aimed to determine the real-world prevalence and investigate risk factors for rheumatoid arthritis (RA)-related lung disease on chest computed tomography (CT) imaging. We also investigated the impact of RA-related lung disease on mortality.

METHODS

We studied chest CT imaging abnormalities among RA patients. We determined the presence and type of abnormalities using the chest CT imaging radiologic report. RA-related lung disease was defined as interstitial lung disease (ILD), bronchiectasis, or pleural disease. We examined whether demographics and RA characteristics were associated with RA-related lung disease using logistic regression. RA-related lung disease and mortality was described using survival curves and Cox regression.

RESULTS

We analyzed 190 patients who had chest CT imaging performed for clinical indications. Mean age was 64.2 years (SD 11.8), 80.0% were female, and 75.3% were seropositive. RA-related lung disease was detected in 54 patients (28.4%); 30 (15.8%) had ILD, 27 (14.2%) had bronchiectasis, and 18 (9.5%) had pleural disease. RA-related lung disease was reported in both seropositive and seronegative RA (28.7% vs. 27.7%, p = 1.00). Male sex (OR 2.62, 95%CI 1.17-5.88) and current methotrexate use (OR 2.73, 95%CI 1.27-5.61 vs. not current) were associated with RA-related lung disease. Twenty-four (44.4%) patients with RA-related lung disease died during mean 7.0 years of follow-up. RA-related lung disease had HR of 5.35 (95%CI 0.72-39.9) for mortality compared to normal chest CT.

CONCLUSIONS

In this real-world study, RA-related lung disease was commonly detected on chest CT imaging regardless of RA serostatus. RA-related lung disease had high mortality, emphasizing the importance in close monitoring of these patients.

Rheumatoid arthritis-associated interstitial lung disease: Current update on prevalence, risk factors, and pharmacologic treatment

Purpose of review

Rheumatoid arthritis-associated interstitial lung disease (RA-ILD) is one of the most serious extra-articular RA manifestations. RA-ILD is associated with worse physical function, lower quality of life, and increased mortality. RA-ILD is comprised of heterogeneous subtypes characterized by inflammation and fibrosis. Diagnosis can be difficult since the presentation of RA-ILD is characterized by non-specific symptoms and imaging findings. Management of RA-ILD is also challenging due to difficulty in precisely measuring pulmonary disease activity and response to treatment in patients who may also have articular inflammation. We provide a current overview of RA-ILD focusing on prevalence, risk factors, and treatment.

Recent findings

Research interest in RA-ILD has increased in recent years. Some studies suggest that RA-ILD prevalence may be increasing; this may be due to underlying biologic drivers or increases in imaging and recognition. Novel RA-ILD risk factors include the MUC5B promotor variant, articular disease activity, autoantibodies, and biomarkers of damaged pulmonary parenchyma. Treatment should focus on controlling RA disease activity, which emerging data suggest may reduce RA-ILD risk. Immunomodulatory and antifibrotic drugs may also treat RA-ILD.

Summary

RA-ILD is an underrecognized and serious manifestation of RA, but important progress is being made in identifying risk factors and treatment.