Neutropenic Fever–Associated Admissions Among Patients With Solid Tumors Receiving Chemotherapy During the COVID-19 Pandemic

This cohort study examines the rates of neutropenic fever–associated admissions and outpatient antibiotic use among patients with cancer receiving chemotherapy before and during the COVID-19 pandemic.


Introduction
Neutropenic fever (NF) occurs in up to 30% of patients with cancer receiving chemotherapy, 1 affecting more than 60 000 patients annually in the US. 2 Only 50% of NF cases have identified causes, but all patients with NF receive empirical antibiotics. 1,2During the COVID-19 pandemic, nonpharmaceutical interventions (NPIs) were instituted to limit the transmission of COVID-19. 3ese NPIs also were associated with decreased rates of common seasonal respiratory viruses. 4VID-19 provided a natural experiment of whether such mitigation strategies may also be associated with reduced rates of NF.In this cohort study, we aimed to determine the association of COVID-19-focused NPIs with the rates of NF-associated admissions and outpatient antibiotic use among patients with cancer who were receiving chemotherapy.

Methods
We performed this single-center, retrospective cohort study comparing hospitalization and outpatient antibiotic use before the COVID-19 pandemic (September 2018 through February 2020) vs the COVID-19 pandemic period (March 2020 through August 2021).This study was determined to be exempt from institutional review board review by the University of Wisconsin.Consent was not obtained because the data were anonymous, per the policy of the University of Wisconsin Health Sciences institutional review board.This study conforms to the Strengthening the Reporting of Observational Studies in Epidemiology (STROBE) reporting guideline for cohort studies. 5Eligible participants were adults from UWHealth with solid tumor diagnoses receiving chemotherapy with a risk of NF.We did not include patients with hematologic malignant entities because their disease would be expected to increase the risk of NF beyond the risk associated with chemotherapy.All NF-associated admissions were recorded. 2The sample size was derived from the number of admissions during the study period.No patients admitted during the study period were excluded.
Outpatient antimicrobial prescriptions, demographic data, and details of cancer diagnosis and chemotherapy were collected.All data were obtained from the electronic health record by 2 trained reviewers (C.J.B. and L.T.S.) to minimize bias.Discrete data were compared using Pearson χ 2 tests, and nondiscrete data were compared using t tests.Statistical significance was set at 2-tailed P < .05.
Analyses were done in November 2022 using Excel software version 2013 (Microsoft).

7%]
).There were no deaths during hospitalization for either period, and no patients were lost to follow-up.Antimicrobial use was not significantly different across the 2 periods (Figure).Internal data (not shown) showed a decrease in positive respiratory virus testing (20.0%before the pandemic vs 7.6% during the COVID-19 pandemic), with no increase in amount of testing performed.
The amount of outpatient oral antibiotics for NF treatment did not change over the study period, at less than 5% of patients in each period.

Discussion
In this cohort study, among patients with solid tumors receiving chemotherapy with a risk of neutropenia, there was a significant reduction in NF-associated admission rates during the COVID-19 pandemic.Antimicrobial use and use of granulocyte colony-stimulating factor were unchanged between the study periods, so we infer from our results that the reduction in NF-associated

Figure
Figure.Outpatient Antimicrobial Consumption for Neutropenic Fever40

Table .
This study involved 3966 patients admitted before COVID-19 (mean age, 59.25 years [range, 19.00-90.00years];50patients hospitalized for NF; 29 men [58.00%]) and 4317 patients admitted during COVID-19 (mean age, 52.11 years [range, 28.00-76.00years];27patients hospitalized for NF; 7 men [25.93%]).The average hospital census size for the oncology service did not decrease over the study period.The patients admitted during COVID-19were more likely to be female and were younger than those admitted before COVID-19.There was This is an open access article distributed under the terms of the CC-BY License.metastaticdisease, number of chemotherapy cycles, or days since chemotherapy between the 2 groups.The use of granulocyte colony-stimulating factor was not significantly different.Before COVID-19, the rate of NF-associated admissions among the at-risk patients was 1.26% (50 of 3966 patients).During the COVID-19 period, this rate decreased to 0.63% (27 of 4317 patients).There was no significant difference in the rate of NF admissions early in the pandemic (March 2020 to September 2020, 18 NF cases of 504 admissions [3.6%]) compared with the second half of the first year of the pandemic (October 2020 to March 2021, 13 NF cases of 484 admissions[2. JAMA Network Open.2023;6(3):e234881.doi:10.1001/jamanetworkopen.2023.4881(Reprinted) March 27, 2023 1/4 Downloaded From: https://jamanetwork.com/ on 09/29/2023 no difference in

Table .
Demographic and Clinical Characteristics of Cohort a Data are only for patients hospitalized with neutropenic fever, not the entire cohort.