Background
Systemic sclerosis related interstitial lung disease (SSc-ILD) causes significant morbidity/mortality. Early diagnosis & treatment with immunosuppression can improve outcome. Some progress to a more fibrotic phenotype (progressive fibrotic ILD: PF-ILD) associated with worsening of variable combination of symptoms/imaging/pulmonary function tests. A novel high-cost drug (nintedanib) is now available targeting lung fibrosis. However, how many patients in the real-world setting that would be eligible for this treatment is unclear. It is important to understand the prevalence to guide appropriate case finding for service planning and cost anticipation.

Aim
Investigate prevalence and annual incidence of PF-ILD in a systemic sclerosis cohort who would the meet criteria for initiation of nintedanib.

Method
Electronic casenotes were searched (from January 2021-23) to identify all patients with systemic sclerosis seen in two UK rheumatology units. Imaging was reviewed by a thoracic radiologist. Cases were assessed against guidelines for PF-ILD diagnosis.

Results
255 patients with SSc were identified based on ACR/EULAR classification. 61/255 (24%) of SSc cohort had ILD on imaging. 14/61 (23%) met criteria for PF-ILD despite immunosuppression. 10/61 (16.4%) had newly met criteria for PF-ILD in the preceding 12 months. Only 7/14 with PF-ILD had been referred to ILD service for consideration of nintedanib.

Conclusion
Real world data shows prevalence of PF-ILD in a well-defined SSc-ILD cohort of 23%. 50% of these had yet to be referred for access to treatment 1 year after it became available in UK implying that case finding may not be complete. An active approach may be required if all patients are to benefit.