Incidence, prevalence, and survival of persons living with advanced cystic fibrosis lung disease in the United States.

BACKGROUND: Persons with advanced cystic fibrosis lung disease (ACFLD) are a subpopulation with specific care needs and unique clinical challenges. In 2019, the Cystic Fibrosis Foundation Patient Registry (CFFPR) introduced new case report forms related to ACFLD. The objective of this study was to estimate the prevalence and incidence of ACFLD 2015-2023. METHODS: ACFLD cases were identified by summarizing individuals with report of supplemental oxygen use, pneumothorax, massive hemoptysis, ppFEV1 < 40, and transplant status. We estimated the incidence of ALD annually, and quantified prevalence accounting for deaths and transplants, compared to case identification using the additional ACFLD case report forms. Kaplan-Meier estimates were used to calculate survival proportions by calendar period and ACFLD qualifying condition. RESULTS: There were 19,117 people who met inclusion criteria; 3,590 incident cases were identified between 2015-2018 and 2,161 incident cases between 2019-2023. Prevalence of ACFLD fell from 6.1% in 2015 to 1.5% in 2023. There were 745 deaths among people meeting ACFLD criteria in 2015-2018 and 158 deaths among incident ACFLD cases 2019-2022. People identified as ACFLD with multiple qualifying conditions had worse survival in both time periods. CONCLUSIONS: Incidence of ACFLD and risk of death has declined from 2015-2023, but 1- and 2-year survival estimates reveal an ongoing need for attention to risk factors for death without lung transplant in this vulnerable population, as those with both ppFEV1 <40 and complications at ACFLD onset have the highest risk of death.