Trends in Patients at Risk for Prolonged Mechanical Ventilation, 2011-2019

Rationale Patients receiving what has been termed “prolonged acute mechanical ventilation” (PAMV, i.e. mechanical ventilation [MV] >96 hours) consume a disproportionate share of hospital and post-acute resources, and a third progress to prolonged mechanical ventilation (MV>14-21 days). Prior estimates (based on 2000-2008 annual growth rates) projected that the incidence of PAMV in 2020 could overwhelm healthcare systems. However, actual trends in incidence and outcomes of PAMV in the last decade, especially just preceding the COVID-19 pandemic, are unclear. Methods Using Medicare Provider Analysis and Review and Master Beneficiary Summary Files from the Center for Medicare and Medicaid Services, we conducted a retrospective cohort study of Medicare fee-for-service beneficiaries >65 years hospitalized between January 1, 2011- December 31, 2019 with admission to an intensive care unit (ICU) who received PAMV (MV>96 hours [ICD-9 96.72 or ICD-10 5A1955Z procedure codes]). We determined annual rates of PAMV out of total MV (ICD-9 96.7, 96.71, 96.72;ICD10 5A1935Z, 5A1945Z, 5A1955Z) and used US Census Bureau population estimates of adults >65 years to derive annual populationstandardized rates of PAMV. Among patients receiving PAMV, we determined annual rates of tracheostomies, median hospital and ICU length of stay, discharge destination, and 90-day and 1-year mortality. We tested for significant trends with Cochrane- Armitage (binary), Cochran-Mantel-Haenszel (categorical) and Jonckheere-Terpstra (continuous outcomes) tests. Results From 2011-2019, a total of 646,677 patients met inclusion criteria. Population-standardized incidence of PAMV decreased from 189 per 100,000 adults >65 years to 112 per 100,000 adults (78,504 to 60,625 individuals, p<0.001), concurrent with a decrease in the total MV population (210,791 to 189,414) and decrease in proportion of PAMV/MV (37% to 32%) (Figure 1). Tracheostomy rates among patients receiving PAMV declined from 21% to 17.5% (p<0.001). Median ICU and hospital length of stay declined from 13 to 12 days (p<0.001) and 16 to 15 days (p<0.001), respectively. Discharge to long-term acute care hospitals was stable at ∼17%;discharge to skilled nursing facilities decreased from 22% to 20% and discharge to hospice increased from 7% to 10% (p<0.001). 90-day mortality increased slightly (61.2% to 62.3% [p=0.01]);1-year mortality remained stable (∼72% [p=0.19]). Conclusions Contrary to prior estimates, the incidence of PAMV declined from 2011-2019. Furthermore, tracheostomy placement and skilled nursing facility use declined with a concurrent increase in hospice use, trends that may reflect improved alignment with patient goals of care. The impact of COVID-19 on incidence of PAMV is unclear. (Figure Presented).