Study: Low oxygen, inflammation predict critical COVID-19 illness, death
Low oxygen levels at hospital admission and signs of inflammation were the strongest predictors of serious COVID-19 illness and death in a prospective cohort study published late last week in BMJ.
Researchers found that 2,741 (51.9%) of 5,279 people testing positive for COVID-19 from Mar 1 to Apr 8 were hospitalized in NYU Langone Health in New York City and Long Island. Of the 2,741 hospitalized patients, 1,739 (69.5%) were released from the hospital, 990 (36.1%) were critically ill, and 665 (24.3%) were released to hospice or died.
Of the 990 critically ill patients, 647 (65.4%) needed mechanical ventilation, 102 (10.3%) needed intensive care but not mechanical ventilation, and 241 (24.3%) were released to hospice or died without receiving either intensive care or mechanical ventilation. Of the 647 patients (23.6%) needing mechanical ventilation, 391 (60.4%) died, and 170 (26.2%) were extubated or released from the hospital.
Advanced age was the strongest predictor of hospitalization, with a double or higher risk for all age-groups older than 44 years and 37.9 odds ratio (95% confidence interval, 26.1 to 56.0) for those 75 years and older.
Risk factors for hospitalization and critical illness also included heart failure, male sex, chronic kidney disease, and body mass index (BMI) greater than 40. But oxygen saturation at hospital admission of less than 88% and high levels of the inflammatory markers troponin, C-reactive protein, and D-dimer were more strongly linked to serious illness than age or underlying illnesses.
Median length of hospitalization was 7 days for all hospitalized coronavirus patients and 36 days for those with serious illness. Of all hospitalized coronavirus patients, 94% have been released from the hospital to hospice or have died.
The risk of serious illness and death declined during the study period, with the lowest risk in the last week, which "raises the possibility that familiarity with the disease, ongoing iteration of protocols and practices in response to observed outcomes, and initiation of new treatments might improve outcomes even in the absence of vaccination or regimens known to be effective," the authors wrote.
May 22 BMJ study
COVID-19 cuts large swath of critical illness, death on West Coast, study finds
The likelihood of COVID-19 patients needing intensive care in Kaiser Permanente healthcare systems in California and Washington state was 40.7%, and the risk of death was 18.9%, according to a prospective cohort study also published in BMJ.
As of Apr 22, 1,840 health system members were hospitalized with COVID-19, including 678 in northern California, 1,059 in southern California, and 103 in Washington. The case-fatality rate was 23.5% in men and 14.9% in women. Risk of death increased with age for both sexes, peaking at 37.3% in hospitalized patients 80 years or older.
Men were more likely than women to require intensive care (48.5% vs 32.0%) and to die (23.5% vs 14.9%). Of the 1,328 people hospitalized by Apr 9 who had 14 days or more of follow-up at data analysis, median patient age was 61 years (range, 18 to 103), with 50% of them 48 to 72 years old, 4 (0.3%) younger than 20 years, 528 (39.8%) 65 years or older, and 162 (12.2%) 80 years or older; 741 (55.8%) were men. Probability of intensive care unit (ICU) admission was 48.5% for men and 32.0% for women.
People infected with COVID-19 on Mar 1 were estimated to infect, on average, 1.39 to 1.54 other people. After public health measures were implemented, the number declined to less than 1, meaning transmission of the virus was slowing.
Median length of hospitalization was 9.3 days among survivors and 12.7 days among those who died. Median length of ICU stay was 10.6 days.
The long median hospital stay indicates that unmitigated transmission of the novel coronavirus could overwhelm US hospital capacity, as it did in Italy and New York City, the authors said. "Hospitals should ensure capacity to manage patients with COVID-19 in the coming months in a manner that is responsive to changes in social distancing or other pandemic mitigating measures," they wrote.
May 22 BMJ study
Swiss study indicates children infrequently transmit COVID-19 to adults
A study today in Pediatrics looked at COVID-19 transmission dynamics in 39 Swiss family household clusters of illnesses and identified only 3 (8%) in which a child was the suspected index patient. The study suggests children most commonly contract the virus from adults, and not vice versa and could favor school reopening.
The study was conducted Mar 10 through Apr 10 via Geneva University Hospital's surveillance network, with 40 children under the age of 16 diagnosed as having COVID-19. Household contact (HHC) information was collected for 39 of those cases. Only 3 households reported having a child with symptom onset preceding any illness in adults. No patients identified in the study required intensive care unit admission, and all saw symptoms resolve within 7 days of infection.
"85% (75/88) of adult HHC developed symptoms at some point, compared to 43% (10/23) of pediatric HHC (p<0.001). Also, 92% (36/39) of mothers developed symptoms, compared to 75% (24/32) of fathers (p=0.04)," the authors wrote.
In a commentary on the study, Benjamin Lee, MD and William V. Raszka, Jr, MD both of the University of Vermont Larner College of Medicine, write that the findings add to a small but growing body of literary that offer encouragement for school reopening. They note that data so far "provide early reassurance that school-based transmission could be a manageable problem and school closures may not have to be a foregone conclusion, particularly for elementary school aged-children who appear to be at the lowest risk of infection."
May 26 Pediatrics study
May 26 Pediatrics commentary