First CDC
Surveillance Data On COVID-19-Associated Hospitalizations Identifies
Risk Factors
The first set of
surveillance data on the characteristics of 1,482 persons hospitalized
due to coronavirus disease during March 2020 confirm early reports
that the largest percentage of persons hospitalized are adults fifty
years of older (74.5%). The overall hospitalization rate for all age
groups during the four week period evaluated was 4.6 per 100,000.
Risk by Age
Hospitalization rates
varied widely by age as shown in the table below with older adults
having rates almost 6 times greater than younger adults 18-49 and
scores-fold higher than children.
|
Age groups |
No. of cases |
Hospitalization rates per 100,000 |
|
0-4 |
6 |
0.3 |
|
5-17 |
6 |
0.1 |
|
18-49 |
366 |
2.5 |
|
50-64 |
461 |
7.4 |
|
65 or older |
643 |
13.8 |
|
Total |
1,482 |
|
Comparison with
Influenza
When
this first four week period of surveillance in this report was
compared to the average rate for a comparable 4 week period over five
recent past influenza seasons (the first four weeks of the flu
season), rates for persons 5-17 years were identical at 0.1 per
100,000, but rates for persons 85 or older in the coronavirus four
week period were significantly higher (17.2 versus 2.2-5.4). This
suggests the greater severity of coronavirus disease compared to
influenza.
Risk by Gender
In
addition to age, the CDC report found that 54.4% of total cases were
male while males account for only 49% of the population in the
catchment area represented by the study. The catchment area includes
all persons in 99 counties in 14 states and represents approximately
10% of the US population.
In a related study of
US pediatric cases, CDC found that a majority (57%) were males. The
agency stated “Reasons for any potential difference in COVID-19
incidence or severity between males and females are unknown…the
predominance of males in all pediatric age groups, including patients
aged <1 year, suggests that biologic factors might play a role in any
differences in COVID-19 susceptibility by sex.”
Underlying Conditions
Only a small
percentage of cases (12%) had data on underlying conditions. Of these
patients, the most prevalent underlying conditions were hypertension,
49.7%, and obesity, 48.3%. These underlying health conditions are very
similar to those found for hospitalized influenza patients in recent
past flu seasons.
These findings for
case numbers are reasonably complete however not all cases had medical
record abstractions completed by the end of March and thus some of the
findings about underlying conditions may change. Also, clinical
outcomes data will be added after the abstractions are completed.
According to CDC,
“ongoing monitoring of hospitalization rates, clinical
characteristics, and outcomes of hospitalized patients will be
important to better understand the evolving epidemiology of COVID-19
in the United States and the clinical spectrum of disease…”
Risk by Race/Ethnicity
In addition, data were
available by race/ethnicity for 580 or 39% of the study population.
|
Race/Ethnicity |
No. of cases |
% |
|
White |
261 |
45 |
|
Black |
192 |
33.1 |
|
Hispanic |
47 |
8.1 |
|
Asian |
32 |
5.5 |
|
American Indian
Alaska Native |
2 |
0.3 |
|
Other or Unk |
46 |
7.9 |
These
data support recent media reports that African Americans are being
disproportionately affected by coronavirus disease likely due in part
to the higher prevalence of the underlying medical conditions already
shown to be risk factors. In the catchment area population, blacks
account for only 18% of the population. Both whites and Hispanics were
underrepresented in the hospital surveillance data.
Time to
Hospitalization
In a small subset of
patients with available data on admission, the surveillance data found
the median interval from symptom onset to admission was 7 days. To
access this Morbidity and Mortality Weekly Report, visit:
https://bit.ly/3evxl1e ■
|