The burden of incidental SARS-CoV-2 infections in hospitalized patients across pandemic waves in Canada
Finlay A. McAlister, Jeffrey P. Hau, Clare Atzema, Andrew D. McRae, Laurie J. Morrison, Lars Grant, Ivy Cheng, Rhonda J. Rosychuk, Corinne M. Hohl, Hana Wiemer, Patrick T. Fok, Samuel Campbell, Kory Arsenault, Tara Dahn, Corinne DeMone, Kavish Chandra, Jacqueline Fraser, Patrick Archambault, Joel Turner, Éric Mercier, Gregory Clark, Éric Mercier, Sébastien Robert, Sébastien Robert, Martyne Audet, Alexandra Nadeau, Audrey Nolet, Xiaoqing Xue, David Iannuzzi, Chantal Lanthier, Laurie J. Morrison, Ivy Cheng, Steven C. Brooks, Connie Taylor, Jeffrey J. Perry, Michelle Welsford, Rob Ohle, Justin Yan, Rohit Mohindra, Megan Landes, Konika Nirmalanathan, Vlad Latiu, Joanna Yeung, Natasha Clayton, Tom Chen, Jenna Nichols, Tomislav Jelić, Kate Mackenzie, Philip J. Davis, Aimee Goss, Andrew D. McRae, Brian H. Rowe, Katie Lin, Stephanie VandenBerg, Jake Hayward, Jaspreet Khangura, Stacey Lobos, Stacy Ruddell, Natalie Runham, Karlin Su, Corinne M. Hohl, Frank Scheuermeyer, Daniel K. Ting, Maja Stachura, Balijeet Braar, J. Andrew Taylor, Ian B.K. Martin, Sean Wormsbecker, Lee Graham, Josie Kanu, Taylor Bootsma, Bernice Huynh, Amanda Swirhun, Tracy Taylor, Mai Hayashi, Mackenzie Cheyne, Neenah Williams, Katherine Lam, Kelsey Compagna, Jeffrey P. Hau, Vi Ho, Serena S Small, Amber Cragg, Vicky X. Xu
Abstract
Many health authorities differentiate hospitalizations in patients infected with SARS-CoV-2 as being "for COVID-19" (due to direct manifestations of SARS-CoV-2 infection) versus being an "incidental" finding in someone admitted for an unrelated condition. We conducted a retrospective cohort study of all SARS-CoV-2 infected patients hospitalized via 47 Canadian emergency departments, March 2020-July 2022 to determine whether hospitalizations with "incidental" SARS-CoV-2 infection are less of a burden to patients and the healthcare system. Using a priori standardized definitions applied to hospital discharge diagnoses in 14,290 patients, we characterized COVID-19 as (i) the "Direct" cause for the hospitalization (70%), (ii) a potential "Contributing" factor for the hospitalization (4%), or (iii) an "Incidental" finding that did not influence the need for admission (26%). The proportion of incidental SARS-CoV-2 infections rose from 10% in Wave 1 to 41% during the Omicron wave. Patients with COVID-19 as the direct cause of hospitalization exhibited significantly longer LOS (mean 13.8 versus 12.1 days), were more likely to require critical care (22% versus 11%), receive COVID-19-specific therapies (55% versus 19%), and die (17% versus 9%) compared to patients with Incidental SARS-CoV-2 infections. However, patients hospitalized with incidental SARS-CoV-2 infection still exhibited substantial morbidity/mortality and hospital resource use.