US Patients With COVID-19 Facing Longer Hospital Stays, Higher Rates of ICU Admission

June 1, 2020

An analysis found that US patients with COVID-19 are experiencing longer hospital stays and higher rates of ICU admissions than patients in China.

Results from a new study found that, among residents of California and Washington state enrolled in Kaiser Permanente health care plans who were admitted to the hospital with coronavirus disease 2019 (COVID-19), the likelihood of intensive care unit (ICU) admission, long hospital stay, and mortality were higher than in these US patients than for patients in China.1

The study, led by researchers at the University of California, Berkeley, and Kaiser Permanente, anonymized approximately 9.6 million medical records of Kaiser Permanente’s health care members in northern California, southern California, and Washington state from the beginning of the year to April 22, 2020.1

Washington state announced the first known imported case of COVID-19 in the United States on January 21, 2020, and California reported its first COVID-19 related deaths as early as February 6, 2020.2 The United States currently reports upwards of 1,790,000 cases and 104,000 deaths.3

Investigators analyzed health care data from Kaiser Permanente health care systems for the 3 regions and found profiles of enrollees by age, race, and sex to be comparable to those of the general populations of California and Washington. However, since the majority of Kaiser Permanente plan members receive coverage through their employer, fewer members either have low incomes or reside in low-income census tracts compared with national or regional averages.2

Recorded encounters stemmed from hospital, outpatient, and telehealth visits, according to the study’s authors.2

The multi-site study included 1840 participants with a first acute hospital admission for confirmed COVID-19 by April 22, 2020 among 9,596,321 health care plan enrollees. A total of 1328 individuals who were admitted by April 9, 2020 were incorporated into the analyses of hospital length of stay and clinical outcomes. Of these patients, 534 were in northern California, 711 in southern California, and 83 in Washington.2

Health care data analyses found, in northern California, a rate of 15.6 per 100,000 cumulative incidences of a first acute hospital admission for COVID-19; 23.3 per 100,000 in southern California; and 14.7 per 100,000 in Washington state.2

Investigators additionally evaluated population data. The median age of patients was 61 years: 58% were between the ages of 48 to 72, 4 (0.3%) patients were younger than 20, 528 (39.8%) were 65 or older, and 162 (12.2%) were 80 or older.2

The study reported that male patients were more likely (48.5%) to be admitted to the ICU than female patients (32.0%).2 Among patients with completed hospital stays and outcomes recorded, 202 (18.4%) had died by end of day on April 22, 2020.2

Data on ICU admissions were available for 1101 patients, only from California, in which 333 were admitted to the ICU. Across all ages and sexes and taking into account censoring of recent hospital admissions, the study’s investigators estimated probability of ICU admission to be 40.7%, whereas the probability of death was 18.9% and increased with age, reaching 37.3% among individuals 80 years of age and older.2

Median hospital stay duration was 9.3 days; among non-survivors it was 12.7 days. For patients requiring critical care, the median duration of ICU stay was 10.6 days.2

The study’s authors wrote that, although incidence rates of COVID-19 hospital admissions increased from late February through mid-March 2020, it has since stabilized or declined due to implementation of social distancing measures.2

Though the Kaiser Permanente demographics provide a well-monitored population with uniform standards of care and health care access that limits the risk of ascertainment bias, the investigators also asserted that the study does not necessarily reflect the general population, as the cohort are likely to have higher socioeconomic status than those without insurance.2

“The epidemiology of COVID-19 in the US remains poorly described, including clinical variables of disease progression, the risk of admission to an intensive care unit (ICU), and death by patient age and sex, and the duration of hospital stay,” the authors wrote. “As such, efforts to forecast trajectories of the epidemic to guide planning and response in the US and other high income settings have relied almost entirely on data from China to inform these variables, which might not adequately reflect clinical circumstances elsewhere.”2


1. Manke K. Long hospital stays, high rates of ICU admission for U.S. COVID-19 patients. Berkeley News. 2020;
2. Lewnard JA, Liu VX, Jackson ML, et al. Incidence, clinical outcomes, and transmission dynamics of severe coronavirus disease 2019 in California and Washington: prospective cohort study. BMJ 2020;369:m1923. doi: ttps://
3. Coronavirus Resource Center. Johns Hopkins University & Medicine. Updated June 1, 2020. Accessed June 1, 2020.