Risk profiles for rheumatoid arthritis-associated interstitial lung disease in a cohort of patients with five-year follow-up.

Objectives: Early identification of interstitial lung disease (ILD) among patients with rheumatoid arthritis (RA) is a challenge for clinicians. The aim of this study was to evaluate screening algorithms for ILD by comparing the proportion of patients assigned a high-risk profile by three recently proposed models.

Method: We used the four-factor risk score, categorizing patients into high and low risk; the ILD screening criteria, categorizing patients into high, intermediate, and low risk; and the risk score for detection of subclinical RA-ILD, with four different risk categories, on patients with RA followed for 5 years after the RA diagnosis with pulmonary function tests, dyspnoea score, and pulmonary imaging.

Results: The four-factor risk score identified 22% of the cohort (25/115) as eligible for further ILD investigations, while the ILD screening criteria identified 37% as high risk (43/115) and 34% as intermediate risk (39/115). The risk score for detection of subclinical RA-ILD identified 44% of the cohort as being at increased risk, with 7% in the highest risk group. The agreement between high-risk groups in the two clinical ILD screening models was moderate (kappa 0.43). Three patients in the cohort had clinical or subclinical ILD, and they were identified as high risk in the two clinical models.

Conclusion: The three algorithms identified approximately one-third of the cohort as being at increased risk of ILD. Further development and validation of these algorithms are needed to reduce false positives and balance the potential benefit of earlier ILD diagnosis and healthcare resources used for respiratory assessment.