{Reference Type}: Journal Article
{Title}: Did COVID-19 ICU patient mortality risk increase as Colorado hospitals filled? A retrospective cohort study.
{Author}: Johnson DR;Ghosh D;Wagner BD;Carlton EJ;
{Journal}: BMJ Open
{Volume}: 14
{Issue}: 5
{Year}: 2024 May 9
{Factor}: 3.006
{DOI}: 10.1136/bmjopen-2023-079022
{Abstract}: <B>OBJECTIVE: </B>To assess whether increasing levels of hospital stress-measured by intensive care unit (ICU) bed occupancy (primary), ventilators in use and emergency department (ED) overflow-were associated with decreasing COVID-19 ICU patient survival in Colorado ICUs during the pre-Delta, Delta and Omicron variant eras.<BR><B>METHODS: </B>A retrospective cohort study using discrete-time survival models, fit with generalised estimating equations.<BR><B>METHODS: </B>34 hospital systems in Colorado, USA, with the highest patient volume ICUs during the COVID-19 pandemic.<BR><B>METHODS: </B>9196 non-paediatric SARS-CoV-2 patients in Colorado hospitals admitted once to an ICU between 1 August 2020 and 1 March 2022 and followed for 28 days.<BR><B>METHODS: </B>Death or discharge to hospice.<BR><B>RESULTS: </B>For Delta-era COVID-19 ICU patients in Colorado, the odds of death were estimated to be 26% greater for patients exposed every day of their ICU admission to a facility experiencing its all-era 75th percentile ICU fullness or above, versus patients exposed for none of their days (OR: 1.26; 95% CI: 1.04 to 1.54; p=0.0102), adjusting for age, sex, length of ICU stay, vaccination status and hospital quality rating. For both Delta-era and Omicron-era patients, we also detected significantly increased mortality hazard associated with high ventilator utilisation rates and (in a subset of facilities) states of ED overflow. For pre-Delta-era patients, we estimated relatively null or even protective effects for the same fullness exposures, something which provides a meaningful contrast to previous studies that found increased hazards but were limited to pre-Delta study windows.<BR><B>CONCLUSIONS: </B>Overall, and especially during the Delta era (when most Colorado facilities were at their fullest), increasing exposure to a fuller hospital was associated with an increasing mortality hazard for COVID-19 ICU patients.