(294) APACHE Risk-Adjusted ICU Outcomes Have Returned to Pre-Pandemic Values

Introduction: Severity-adjusted mortality early in COVID-19 exceeded that of usual viral pneumonia. Standardized Mortality Ratios (SMR) and length-of-stay (LOS) in ICU patients thus increased during the pandemic. Higher SMR were also seen in non-COVID patients during times of high COVID census.

Methods: Anonymized data limited to non-surgical, non-trauma patients age>45 was provided by 31 hospitals continuously contributing APACHE-IVb data for calendar years 2016-22. Outcomes included ICU/hospital mortality, LOS, % active treatment, ventilator days and associated APACHE standardized ratios.

Results: 31 hospitals (3 large teaching, 13 small teaching, 15 community) provided data on 314,652 ICU admissions; 53% male; 74% Caucasian, 17% Black. Overall hospital mortality (2016-22) was 13.2%; SMR 0.96. SMR was significantly better (0.89-0.96) than expected 2017-19, deteriorated to 1.37 in 21Q3 and averaged 0.98 in CY22. Increased SMR was seen in all age groups during 2020-21, more pronounced in age 45-64 (1.17) than age>75 (1.07). ICU and hospital LOS peaked at 5.19 and 10.0 days in late 2021, reverting to baseline (3.84/8.90) in 2022. Aside from 21Q4 (SMR 1.10; p< 0.01), SMR was not significantly impacted in non-COVID patients, but was as high as 2.39 in COVID patients during 2021. COVID SMR returned to 1.02 after 22Q3. Active treatment in ICU was 59% before COVID; 62% in 2020-21, and 60% in 2022. Ventilator days were 4.5 pre-COVID; peaked at 6.8 in 21Q3 and returned to 4.4 in CY22.

Conclusions: APACHE risk-adjusted outcomes have normalized since Omicron became the dominant variant in the US. Data is insufficient to determine if this results from better ICU care, lower lethality of newer variants, higher population vaccination rates or other causes. These results indicate that the COVID-related impact on APACHE-benchmarked outcomes had largely resolved by CY22.