RA disease activity, functional status independently associated with survival in RA-ILD
In patients with rheumatoid arthritis-associated interstitial lung disease, more severe RA disease activity and impaired functional status were associated with increased mortality, according to data presented at ACR Convergence 2021.
Patients diagnosed with RA-ILD generally have poor long-term outcomes “with a median survival estimated between 3 to 8 years.” Although it has been demonstrated that ”more severe pulmonary disease is associated with reduced survival,” the impact of RA disease activity on long-term outcomes in RA-ILD is less understood, according to Rebecca Brooks, BS, medical student at the University of Nebraska Medical Center, and colleagues.
“We aimed to determine whether RA disease activity and functional status, as measured by DAS28-ESR and MDHAQ, were independently associated with survival in RA-ILD,” the researchers wrote.
The study included 227 patients with RA-ILD sourced from a multicenter, prospective RA cohort registry containing patient data from 2003 to 2019. Researchers used the registry and linked administrative data to collect data on demographics, seropositivity, RA disease duration and RA medications. The Multidimensional Health Assessment Questionnaire (MDHAQ) and DAS28-ESR collected functional status and RA disease activity, respectively, while disease-modifying antirheumatic drugs determined the independent associations of RA disease activity and ILD severity with survival.
There were 108 deaths reported over 1,073 person-years of follow-up, with respiratory disease as the leading cause and accounting for 28% of deaths. The median survival was 6.7 years after index date.
When examined separately, DAS28-ESR, MDHAQ and pulmonary measures of severity were all independently associated with mortality. After adjusting for predicted forced vital capacity percentage, the association between DAS28-ESR (HR 1.22; 95% CI 1.04-1.43) and MDHAQ (HR 1.89; 95% CI 1.33-2.69) with mortality persisted.
When assessing RA disease activity in conjunction with pulmonary severity, moderate-to-high RA disease activity and impaired forced vital capacity were associated with a significantly higher risk of death (HR 3.09; 95% CI 1.17-8.18) as compared with those with remission or low disease activity and normal forced vital capacity. Impaired forced vital capacity in combination with moderate-to-high RA disease activity held the highest risk of death (HR = 4.49; 95%, CI 1.72-11.71), according to the presentation.
“Ongoing collection of these key RA disease severity measures is valuable for prognosticating the disease course of RA-ILD patients,” the researchers wrote. “Assessment of these patients should not be limited to their pulmonary disease status. Whether tailoring treatments in RA-ILD based on these measures can improve survival will require further study.”
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Brooks R, et al. Abstract #1918. Presented at: ACR Convergence 2021; November 3-10, 2021 (virtual meeting).