Risk assessment score guides screening of systemic sclerosis-associated interstitial lung disease
Presenter: Cosimo Bruni, MD, PhD, University of Florence, Florence, Italy
Developing a screening tool for the detection of interstitial lung disease in systemic sclerosis: the ILD-RISC score. Abstract 1526. Presented November 13, 2022.
Researchers develop a risk assessment scoring system to guide the use of high-resolution computed tomography to detect interstitial lung disease in patients diagnosed with systemic sclerosis.
Interstitial lung disease (ILD) is a common complication and cause of death in patients with systemic sclerosis. “High-resolution computed tomography (HRCT) is the gold standard for diagnosing systemic sclerosis-associated ILD; however, not all patients undergo HRCT screening when first diagnosed with systemic sclerosis,” according to presenter Cosimo Bruni, MD, PhD, University of Florence, Florence, Italy. “It is also unclear when the test should be repeated during follow-up of patients who are negative at baseline.”
Researchers set out to develop an ILD risk assessment score (ILD-RISC score) to guide physicians in ordering baseline and follow-up HRCT. They had identified that only about two-thirds of physicians use HRCT to regularly screen patients for ILD at the time of systemic sclerosis diagnosis. This percentage drastically drops to less than 15% during follow-up visits, he said.
“There are also a certain number of physicians who prefer to be guided by signs, symptoms, or other tests to prescribe a chest HRCT. We therefore wanted to create a tool that guides clinicians about HRCTs, both at diagnosis and follow-up,” Bruni said.
The researchers selected 13 variables considered important in the identification of systemic sclerosis-associated ILD: sex, age, time from first non-Raynaud’s phenomenon sign or symptom, skin subset, presence of esophageal symptoms, current or past digital ulcers, arthritis, smoking, increased inflammatory markers, New York Heart Association functional class, positive systemic sclerosis autoantibodies, the percent of forced vital capacity, and diffusing capacity of the lungs for carbon monoxide.
The prediction model for ILD was based on baseline visits from systemic sclerosis patients in 6 European referral centers using multivariable logistic regression with backward selection. Of the 780 patients, 533 patients (43% with ILD) and 247 patients (48% with ILD) were randomly assigned to the derivation and validation cohorts, respectively. Selected laboratory, clinical, and pulmonary function features in the statistical model were combined to obtain the ILD-RISC score. An ILD-RISC score of 0.3 or greater showed 85.6% sensitivity of 53.6% specificity and was chosen as a cut-off, Bruni said. Those values were replicated in the validation cohort and applied longitudinally in a cohort of systemic sclerosis patients with negative baseline HRCT.
Among 819 patients with negative baseline HRCT, 170 (20.8%) developed ILD during a 3.8-year follow-up (1988 visits). Longitudinally, the ILD-RISC score showed comparable sensitivity and specificity, resulting in almost 50% of visits in which the HRCT could be correctly skipped following an ILD-RISC score of less than 0.3.
“It is important to diagnose ILD early in order to start treatment,” Bruni said. “We still recommend performing HRCT screening in all patients if the test is readily available and patients are willing to undergo it, so as not to miss any patient with ILD. However, in situations where HRCT is not available or there are patient concerns about HRCT or the physician prefers to order it only in select patients, our ILD-RISC score supports the ability of HRCT to identify this complication while also helping clinicians avoid HRCT when not indicated. Most importantly, it may help to decide when to order HRCTs at follow-up, thus limiting unnecessary exams.”
Bruni noted the score’s relatively low specificity led to a certain number of false positives, which is a limitation of the study. Researchers are working to further improve the score and continue to reduce the number of unnecessary HRCTs, he said.
Reference
Bruni C, Tofani L, Fretheim H, et al. Developing a screening tool for the detection of interstitial lung disease in systemic sclerosis: the ILD-RISC score [abstract 1526]. Arthritis Rheumatol 2022; 74(suppl 9). https://acrabstracts.org/abstract/developing-a-screening-tool-for-the-detection-of-interstitial-lung-disease-in-systemic-sclerosis-the-ild-risc-risk-score
Disclosures
Cosimo Bruni: Boehringer Ingelheim, Eli Lilly and Company.