Systemic Sclerosis and Interstitial Lung Disease: An Intertwined Revelation

Roughly 4% to 6% of people with systemic scleroderma (SSc) were found to exhibit early symptoms of interstitial lung disease (ILD), researchers found in a recent observational study. The findings are published in the August issue of the online journal Medicine.

The authors strongly recommend clinical examination and serologic testing in patients presenting with an ILD “to exclude autoimmune disease as the underlying cause, as recommended in international diagnostic guidelines.” They added, “these data support previous studies showing that SSc can damage the lungs early in the course of the disease. Expert groups have proposed that all patients diagnosed with SSc should be screened for ILD.”

Using data from the Optum’s Clinformatics Data Mart Database, a large U.S. insurance claims database, the authors divided the patients into 2 groups: International Classification of Diseases, Clinical Modification 9 (ICD-9-CM), ninth revision, used until October 2015, and the ICD-10-CM group (the tenth and current revision). The ICD-9-CM group included 1,779 patients while the ICD-10-CM group consisted of 1,032 patients, treated between January 2007 and June 2019.

The investigators defined the existence of ILD as 2 or more medical claims associated with ILD on different dates. “An ILD finding prior to SSc was determined through a second ILD claim filed by a patient before a first, or index, claim for SSc,” they clarified.

The study revealed that in the ICD-9-CM group, a second ILD medical claim prior to the SSc index date was recorded for 136 patients (7.6%). In the ICD-10-CM group, 96 patients (9.3%) showed a second ILD claim. Furthermore, 76 patients (4.3%) in the ICD-9-CM group and 58 patients (5.6%) in the ICD-10-CM group had their second ILD medical claim more than 1 year before a first SSc claim.

Overall, “analyses of a large US health insurance database showed that 4% to 6% of patients with SSc had claims for ILD over 1 year prior to a claim for SSc,” the researchers wrote, demonstrating the importance of screening patients with ILD for SSc as well as screening patients with SSc for ILD.

—Priyam Vora

Reference:
Elizabeth V, Shervin A, Nan S et al. Understanding diagnostic pathways in systemic sclerosis and systemic sclerosis-associated interstitial lung disease: A retrospective cohort study. Medicine. 2022; 101(32) DOI: 10.1097/MD.0000000000029993