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

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.

Risk of incident cardiovascular events with disease-modifying anti-rheumatic drugs among adults with rheumatoid arthritis: a nested case-control study

OBJECTIVE

This study examined the risk of cardiovascular disease (CVD) associated with the disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA).

METHOD

This nested case-control study used the MarketScan database (2012-2014), involving adult RA patients (aged ≥18 years) initiating either a conventional synthetic (cs) DMARD, biologic DMARD, or targeted synthetic (ts) DMARD between January 1, 2013 and December 31, 2014 (cohort entry) and had no CVD history. Cases were individuals with incident CVD identified using diagnosis codes or procedure codes from medical claims. For each case, 10 age- and sex-matched controls were selected using the incident density sampling with replacement. Prescriptions of DMARDs were measured 90 days before the event date. Conditional logistic regression examined the association of risk of CVD with DMARDs in combination treatment or individual use, with reference to methotrexate (MTX) monotherapy, adjusting for baseline confounders. Subgroup analyses were performed separately in DMARD combination therapy users or individual DMARD users, respectively.

RESULTS

In total, 270 cases of incident CVD and 2700 controls were included (mean [standard deviation (SD)] age: 54 [1]; 75.6% women). The commonly prescribed DMARD therapies were csDMARD monotherapy (n = 795, 27.04%), followed by  tumor necrosis factor inhibitors (TNFi) monotherapy (n = 367, 12.48%), and TNFi in combination with MTX (n = 314, 10.68%). Compared with MTX monotherapy, overall use of DMARD agents was not associated with the differential risk of CVD, including various types of DMARD combination regimens. The findings were similar across subgroup analyses.

CONCLUSIONS

The study found no differential risk of CVD with DMARDs in combination therapy or monotherapy compared to MTX monotherapy in patients with RA. Key Points • This study evaluated the risk of cardiovascular disease (CVD) associated with the disease-modifying anti-rheumatic drugs (DMARDs) in rheumatoid arthritis (RA). • Findings suggest no differential CVD risk with DMARDs in combination with MTX or used individually compared with MTX monotherapy in patients with early RA. • Further efforts should focus on a better understanding of the mechanism of DMARD combination treatments with MTX in modifying CV risk.

Increased mortality in patients with RA-associated interstitial lung disease: data from a French administrative healthcare database

OBJECTIVES

Interstitial lung disease (ILD) is a severe extra-articular manifestation of rheumatoid arthritis (RA). The objectives of this study were to estimate mortality rate in patients with RA-ILD and identify factors affecting mortality.

METHODS

Data from a French national claims database (Système National des Données de Santé) from 2013 to 2018 were analysed. Adults with an RA diagnosis (International Classification of Diseases (ICD)-10 codes M05, M06.0, M06.8 and M06.9) were included. ILD diagnosis was defined with ICD-10 code J84. Mortality rates were compared between patients with RA with and without ILD, using Cox proportional hazards regression, after matching 1:1 for age, sex, age at RA-ILD onset and RA duration.

RESULTS

Among 173 132 patients with RA, 4330 (3%) also had ILD (RA-ILD). After matching, RA-ILD was associated with an increased mortality rate (HR 3.4, 95% CI 3.1 to 3.9). The HR for mortality was greater for: patients aged <75 years (HR 4.8, 95% CI 3.9 to 5.9) versus ≥75 years (HR 3.0, 95% CI 2.6 to 3.5); patients with ILD onset occurring before RA onset (HR 8.4, 95% CI 5.5 to 13.0) versus ILD onset occurring after RA onset (HR 2.9, 95% CI 2.6 to 3.3); and men (HR 5.2, 95% CI 4.4 to 6.2) versus women (HR 3.6, 95% CI 3.0 to 4.2).

CONCLUSION

In this nationwide cohort study, RA-ILD was associated with increased mortality rate (vs in patients with RA without ILD), notably for those aged <75 years, those whose ILD preceded RA onset and men.

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.

Interstitial lung disease in rheumatoid arthritis: incidence, prevalence and related drug prescriptions between 2007 and 2020

OBJECTIVE

To investigate prevalence, incidence and medication of interstitial lung disease (ILD) among German individuals with rheumatoid arthritis (RA).

METHODS

Nationwide BARMER claims data from 2007 to 2020 were used. RA-ILD was identified by diagnosis codes, prescription of disease-modifying antirheumatic drugs (DMARDs) and lung diagnostics. ILD was assigned as incident or prevalent relative to the year of the first diagnosis. We identified prescriptions of glucocorticoids, conventional synthetic (cs), biological (b) and targeted synthetic (ts)DMARDs, antifibrotics and rheumatology and/or pulmonology care.

RESULTS

Among all persons with RA (40 686 in 2007 to 85 175 in 2020), 1.7%-2.2%/year had ILD with a slight decline since 2013. Incident ILD was 0.13%-0.21% per year and remained stable over time. ILD was more common in seropositive RA, in men and in the elderly (mean age 72 years in 2020). Glucocorticoids (84% to 68%), csDMARD (83% to 55%) and non-steroidal anti-inflammatory drug use (62% to 38%) declined, while bDMARDs (16% to 24%) rose. In 2020, 7% received tsDMARDs, 3% antifibrotics, 44% analgesics and 30% opioids. DMARD therapy was more common if a rheumatologist was involved and antifibrotics if a pulmonologist was involved. Opioid use was highest if no specialist was involved (39%) but also common in rheumatology care (32%) and less frequent in pulmonology care (21%).

CONCLUSIONS

RA-ILD is rare and mainly affects elderly persons. No trend in incidence was observed but treatment strategies have enlarged. Specialist care is necessary to provide disease-specific therapies. The continuing high analgesic and opioid demand shows unmet needs in these patients.