Letters: Characteristics of Hospitalized Adults With COVID-19 in An Integrated Health Care System in California
Letters: Characteristics of Hospitalized Adults With COVID-19 in An Integrated Health Care System in California
Letters: Characteristics of Hospitalized Adults With COVID-19 in An Integrated Health Care System in California
RESEARCH LETTER data, and highest level of respiratory support. Patients were
treated according to national guidelines for pneumonia and
Characteristics of Hospitalized Adults With COVID-19 acute respiratory distress syndrome. We report numbers
in an Integrated Health Care System in California (percentages) for binary/categorical variables and medians
Coronavirus disease 2019 (COVID-19) has resulted in in- (interquartile ranges) for continuous variables. As of April 9,
creased hospital and intensive care unit (ICU) use. In the United 2020, 14.8% of the cohort was still hospitalized. In-hospital
States, few reports have characterized patients treated outside mortality estimates were calculated for patients with dis-
of the ICU.1 Northern California was an early epicenter of se- charge dispositions as of April 9, 2020.
vere acute respiratory syndrome coronavirus 2 (SARS-CoV-2) The KPNC institutional review board approved the proj-
community transmission in the United States. We report ect with a waiver of informed consent.
hospitalization and ICU admissions from Kaiser Permanente
Northern California (KPNC), a regional integrated health care Results | Of 16 201 tests in adults, results from 1299 patients
system serving 4.4 million members, constituting 30% of the (8.0%) were positive for SARS-CoV-2. Of these patients, 377
area’s insured population. (29.0%) were treated as inpatients and 113 (8.7%) were treated
in the ICU.
Methods | We performed a retrospective cohort study of The median age was 61.0 years (interquartile range, 50.0-
adults (≥18 years) with nasal/throat swabs positive for 73.0); 56.2% were men (Table). The most common comorbid-
SARS-CoV-2 by polymerase chain reaction hospitalized ity was hypertension (n = 164, 43.5%). Of 166 patients who un-
between March 1, 2020, and March 31, 2020, at 21 KPNC derwent testing for influenza A/B or respiratory syncytial virus
hospitals. Tests were approved by infectious disease physi- (44.0% of the cohort), none tested positive. Bilateral infil-
cians based on public health and local guidelines. Patients trates on chest film were seen in 63.4% (n = 239). Overall, 34
were triaged according to clinician judgment. No patients patients (9.0%) received a prednisone-equivalent dosage of
were lost to follow-up. 20 mg/d or more.
We characterized patients by demographics, comorbid Most patients were treated on the general ward or inter-
disease,2 severity of illness,2 ICU use, laboratory/chest film mediate care unit (n = 264, 70.0%); of whom 54.9% received
Table. Characteristics of Adult Patients Hospitalized With Coronavirus Disease 2019 in Northern Californiaa
No. (%)
Adults treated
on general ward Adults treated
or intermediate care unit in intensive care unit
All adults (N = 377) (n = 264) (n = 113)
Age, median (IQR), y 61.0 (50.0-73.0) 60.0 (49.0-72.0) 63.0 (53.0-73.0)
Sex
Male 212 (56.2) 138 (52.3) 74 (65.4)
Female 165 (43.8) 126 (47.7) 39 (34.5)
COPS2, median (IQR)b 13.0 (10.0-33.0) 13.0 (10.0-35.0) 10.0 (9.0-32.0)
Comorbidities
Hypertension 164 (43.5) 106 (40.2) 58 (51.3)
Diabetes 118 (31.3) 73 (27.7) 45 (39.8)
Chronic kidney disease 48 (12.7) 36 (13.6) 12 (10.6)
COPD or asthma 28 (7.4) 20 (7.6) 8 (7.1)
Congestive heart failure 22 (5.8) 18 (6.8) 4 (3.5)
Liver cirrhosis 21 (5.6) 14 (5.3) 7 (6.2)
Malignancy 18 (4.8) 12 (4.5) 6 (5.3)
LAPS2, median (IQR)c 72.0 (52.0-95.0) 64.0 (49.0-83.0) 93.0 (73.0-115.0)
Chief symptom in emergency department
Shortness of breath 185 (49.1) 118 (44.7) 67 (59.3)
Fever 127 (33.7) 88 (33.3) 39 (34.5)
Cough 120 (31.8) 80 (30.3) 40 (35.4)
(continued)
Table. Characteristics of Adult Patients Hospitalized With Coronavirus Disease 2019 in Northern Californiaa (continued)
No. (%)
Adults treated
on general ward Adults treated
or intermediate care unit in intensive care unit
All adults (N = 377) (n = 264) (n = 113)
Initial laboratory tests, median (IQR)d
White blood cell count, ×109/L 6.4 (4.7-8.5) 6.2 (4.6-8.1) 7.3 (5.4-9.2)
Reference range 3.7-11.1
Absolute neutrophil count, ×109/L 4.8 (3.3-6.7) 4.3 (3.1-5.9) 5.6 (3.9-7.4)
Reference range 1.8-7.9
Absolute lymphocyte count, ×109/L 1.0 (0.7-1.4) 1.0 (0.7-1.4) 0.9 (0.7-1.2)
Reference range 0.9-3.2
Creatinine, mg/dL 0.9 (0.7-1.1) 0.9 (0.7-1.0) 0.9 (0.8-1.2)
Reference range ≤1.11
Lactate, mmol/L 1.2 (1.0-1.6) 1.2 (0.9-1.5) 1.4 (1.0-1.8)
Reference range 0.5-1.9
AST, U/L 36.0 (25.0-56.0) 34.0 (24.0-55.0) 39.0 (31.0-58.0)
Reference range 10-40
ALT, U/L 29.0 (19.0-47.0) 28.0 (18.0-48.0) 29.0 (21.0-41.0)
Reference range 0-41
Total bilirubin, mg/dL 0.6 (0.4-0.8) 0.5 (0.4-0.7) 0.6 (0.5-0.9)
Reference range 0.2-1.2
LDH, U/L 302 (224-398) 288 (212-365) 345 (274-489)
Reference range ≤270
Viral respiratory panel
Influenza A/B 0 0 0
Respiratory syncytial virus 0 0 0
Initial chest film result, opacities
None 62 (16.4) 55 (20.8) 7 (6.2)
Unilateral 61 (16.2) 51 (19.3) 10 (8.8)
Bilateral 239 (63.4) 143 (54.2) 96 (85.0)
Highest level of respiratory support
Nasal cannula/face mask 150 (39.8) 145 (54.9) 5 (4.4)
High-flow oxygen 12 (3.2) 8 (3.0) 4 (3.5)
Noninvasive ventilation 8 (2.1) 7 (2.7) 1 (<1)
Invasive ventilation 110 (29.2) 7 (2.7)e 103 (91.2)
Received steroid equivalent 34 (9.0) 20 (7.6) 14 (12.4)
to prednisone ≥20 mg/d while inpatient
Abbreviations: ALT, alanine aminotransferase; AST, aspartate aminotransferase; the univariate relationship of COPS2 score with 30-day mortality was as
COPD, chronic obstructive pulmonary disease; COPS2, Co-morbidity Point follows: 0-39, 1.7%; 40-64, 5.2%; and ⱖ65, 9.0%.2
Score version 2; IQR, interquartile range; LAPS2, Laboratory-based Acute c
LAPS2 is assigned based on a patient’s worst vital signs, pulse oximetry,
Physiology Score version 2; LDH, lactate dehydrogenase. neurological status, and 16 laboratory test results in the 72 hours preceding
SI conversion factors: To convert ALT, AST, and LDH to μkat/L, multiply by hospitalization. Prior to the pandemic, the univariate relationship of an
0.0167; bilirubin to μmol/L, multiply by 17.104; creatinine to μmol/L, multiply by admission LAPS2 score with 30-day mortality was as follows: 0-59, 1.0%;
88.4; and lactate to mg/dL, divide by 0.111. 60-109, 5.0%; and ⱖ110, 13.7%.2
a d
Hospitalizations can occur as observations or inpatient admissions. If a patient Most patients underwent these laboratory tests (>97% for cell counts and
had a rehospitalization, data from the first hospitalization are reported. creatinine, 88% for lactate, 80% for liver function tests, and 52% for LDH).
b e
COPS2 is assigned based on all diagnoses incurred by a patient in the Patients treated in intermediate care units capable of mechanical ventilation.
12 months preceding the index hospitalization. Prior to the pandemic,
supplemental oxygen through nasal cannula/face mask. A total aged adults (≤59 years) who were hospitalized (n = 172, 45.6%)
of 113 inpatients (30.0%) required ICU admission and 110 was similar to the proportion of older adults (≥60 years) who
(29.2%) received invasive mechanical ventilation. were hospitalized (n = 205, 54.4%).
Patients aged 60 to 69 years represented the most com- Of 321 patients with discharge dispositions, 50 (15.6%) died
mon age group both hospitalized (n = 93, 24.6%) and admit- in the hospital. Of 253 patients treated on the ward with dis-
ted to the ICU (n = 31, 27.4%) (Figure). However, adults of all charge dispositions, 16 (6.3%) died. Of 68 patients treated in
ages were admitted, and the proportion of younger and middle- the ICU with discharge dispositions, 34 (50.0%) died.