Outcomes of hospitalized patients with COVID-19 during the course of the pandemic in a fully integrated health system

Abstract

Background Given the rapid spread of COVID-19 and its associated morbidity and mortality, healthcare providers throughout the world have been forced to constantly update and change their care delivery models. Objective To assess the outcomes of COVID-19 hospitalized patients during the course of the pandemic in a well-integrated health system. Methods The study used data from the electronic health medical records to assess trends in clinical profile and outcomes of hospitalized adult COVID-19 patients hospitalized in our 5-hospital health system from March 2020-May 2021 (n = 6865). Integration of the health system began in February 2020 and was fully actualized by March 30, 2020. Results Mortality decreased from 15% during first peak (March-May 2020; the rate includes 19% in March-April and 10% in May 2020) to 6% in summer-fall 2020, increased to 13% during the second peak (November 2020-January 2021), and dropped to 7% during the decline period (February-May 2021) (p<0.01). Resource utilization followed a similar pattern including a decrease in ICU use from 35% (first peak) to 16% (decline period), mechanical ventilation from 16% (first peak, including 45% in March 2020) to 9–11% in subsequent periods (p<0.01). Independent predictors of inpatient mortality across multiple study periods included older age, male sex, higher multi-morbidity scores, morbid obesity, and indicators of severe illness on admission such as oxygen saturation ≤90% and high qSOFA score (all p<0.05). However, admission during the first peak remained independently associated with increased mortality even after adjustment for patient-related factors: odds ratio = 1.8 (1.4–2.4) (p<0.0001). Conclusions The creation of a fully integrated health system allowed us to dynamically respond to the everchanging COVID-19 landscape. In this context, despite the increasing patient acuity, our mortality and resource utilization rates have improved during the pandemic.

The impact of variants and vaccination on the mortality and resource utilization of hospitalized patients with COVID-19

“…S1). The clinical profile and outcomes of our inpatients with COVID positivity during the pre-Delta period have been previously published [ 4 ].…”

“…As noted in our prior study, data were collected from electronic medical records (EMRs) of adults (≥ 18 years) with a diagnosis of COVID-19 (ICD-10 code U07.1) who were hospitalized in our health system [ 4 ]. The data for this study were collected over a longer period of time and are inclusive of March 5th, 2020 to February 5th, 2022.…”

“…Charlson comorbidity index (CCI) and Elixhauser comorbidity index (ECI) scores which are used in clinical practice to predict comorbid patients’ risk of mortality were calculated from the EMRs [ 4 ]. Obesity was defined as a body mass index (BMI) ≥ 30, morbid obesity was defined as a BMI ≥ 40.…”

“…In fact, this pattern of infection spread was followed across most of the U.S. in 2020–2021 although exact timing varied between regions. The earliest studies indicated that patient clinical and demographic profile were major drivers of adverse outcomes so that older patients and those with comorbidities were at a significantly higher risk for hospitalization and mortality [ 4 , 5 ].…”

“…Our aim was to build upon our previous work [ 4 ] conducted during the first two phases of the pandemic by evaluating the outcomes of hospitalized patients with COVID-19 as the pandemic has now moved through the multiple stages, this time with a targeted focus on outcomes related to the dominant variants and patients’ vaccination status.…”