Nirmatrelvir-ritonavir use among adults hospitalized with COVID-19 during the Omicron phase of the COVID-19 pandemic, Canadian Nosocomial Infection Surveillance Program

• Published in: Canada communicable disease report Vol. 49; no. 7-8; pp. 351 - 357
• Main Authors: Mitchell, Robyn, Lee, Diane, Pelude, Linda, Comeau, Jeannette, Conly, John, Ellis, Chelsey, Ellison, Jennifer, Embil, John, Evans, Gerald, Johnston, Lynn, Johnstone, Jennie, Katz, Kevin, Kibsey, Pamela, Lee, Bonita, Lefebvre, Marie-Astrid, Longtin, Yves, McGeer, Allison, Mertz, Dominik, Minion, Jessica, Smith, Stephanie, Srigley, Jocelyn, Suh, Kathryn, Tomlinson, Jen, Wong, Alice, Thampi, Nisha, Frenette, Charles
• Format: Journal Article
• Language: English
• Published: Canada Public Health Agency of Canada 01.08.2023
• Series: Enteric Diseases: A Major Health Problem in Canada
• Subjects: Surveillance; COVID-19; hospitalized patients; nirmatrelvir-ritonavir; Omicron
• DOI: 10.14745/ccdr.v49i78a07
• ISSN: 1188-4169; 1481-8531

Recent studies have demonstrated the effectiveness of nirmatrelvir-ritonavir in reducing the risk of progression to severe disease among outpatients with mild to moderate coronavirus disease 2019 (COVID-19); however, data are limited regarding the use and role of nirmatrelvir-ritonavir among hospitalized patients. This study describes the use and outcomes of nirmatrelvir-ritonavir among adults hospitalized with COVID-19 in a sentinel network of Canadian acute care hospitals during the Omicron variant phase of the pandemic. The Canadian Nosocomial Infection Surveillance Program conducts surveillance of hospitalized patients with COVID-19 in acute care hospitals across Canada. Demographic, clinical, treatment and 30-day outcome data were collected by chart review by trained infection control professionals using standardized questionnaires. From January 1 to December 31, 2022, 13% (n=490/3,731) of adult patients (18 years of age and older) hospitalized with COVID-19 in 40 acute care hospitals received nirmatrelvir-ritonavir either at admission or during hospitalization. Most inpatients who received nirmatrelvir-ritonavir, 79% of whom were fully vaccinated, had at least one pre-existing comorbidity (97%) and were of advanced age (median=79 years). Few were admitted to an intensive care unit (2.3%) and among the 490 nirmatrelvir-ritonavir treated inpatients, there were 13 (2.7%) deaths attributable to COVID-19. These findings from a large sentinel network of Canadian acute-care hospitals suggest that nirmatrelvir-ritonavir is being used to treat adult COVID-19 patients at admission who are at risk of progression to severe disease or those who acquired COVID-19 in hospital. Additional research on the efficacy and indications for nirmatrelvir-ritonavir use in hospitalized patients is warranted to inform future policies and guidelines.