The impact of COVID-19 lockdown measures on rates of febrile neutropenia in a cohort of Irish patients receiving chemotherapy

ABSTRACT

Background: Febrile neutropenia in patients receiving chemotherapy is a life-threatening condition requiring prompt attention. This condition may also result in dose reductions, delays, or discontinuations of chemotherapy which compromise patient outcomes. This study seeks to evaluate the impact of COVID19 “lockdown” public health measures in Ireland on the incidence of febrile neutropenia in patients who were receiving cytotoxic chemotherapy regimens. Methods: All patients receiving chemotherapy at the Bon Secours Hospital Cork who were admitted with neutropenia and fever during two separate time periods were included in the study 1st April 2018 to 31st March 2019 (“pre-pandemic year”) and 1st April 2020 to 31st March 2021 (“pandemic year”). The pandemic year selected equates to a period of heightened infection control measures in Irish society, featuring public health advice re social distancing, routine mask wearing in public and successive lockdown waves. Retrospective chart review was performed on all patients admitted to the oncology inpatient ward who had blood cultures on admission to determine the number of these patients who were neutropenic at the time of blood culture draw. Similarly, pharmacy records were accessed to determine the number of unique chemotherapy items dispensed in each year in order to establish a rate of febrile neutropenia episodes per 100 chemotherapy items dispensed for each period. The incident rate ratio was calculated using the Exact Poisson Test. Results: During the pre-pandemic year there were 57 individual admissions with febrile neutropenia compared with 32 admissions during the pandemic year. There were 4581 chemotherapy units dispensed during the pre-pandemic year compared to 4628 during the pandemic year. The rate of febrile neutropenia episodes per 100 chemotherapy units dispensed was 1.24 (95% CI 0.94, 1.61) in the pre-pandemic year and 0.69 (95% CI 0.47, 0.98) in the pandemic year. The incident rate ratio is 1.80 (95% CI 1.14, 2.87, two-sided P = 0.007). 9 of 57 (16%) admissions in the pre-pandemic year were associated with positive blood cultures compared with 4 of 32 (13%) in the pandemic year (not significant by Fisher's exact test). Conclusions: Increased precautionary infection control measures during the COVID19 pandemic public health restrictions correlated with a significant reduction in the rate of febrile neutropenia amongst patients receiving cytotoxic chemotherapy. This suggests that there may be a role for similar measures for this patient cohort in the post-pandemic period. Options which patients may consider to employ include social distancing, wearing face-coverings and restricting social contacts while at risk of neutropenia from cytotoxic chemotherapy regimens.