Estimating Preventable COVID19 Infections Related to Elective Outpatient Surgery in Washington State: A Quantitative Model

Yuemei Zhang; Sheng-Ru Cheng

of 2019, COVID-19 spread explosively across the globe and was officially declared a pandemic by the WHO on March 11, 2020. 1 In the United States, the number of confirmed cases has spiked from just 1 case between Jan. 20, 2020 to 4661 confirmed positives and 85 deaths as of March 16, 2020. 2 Washington state, the original epicenter of the US outbreak and the location of the first American case, has had 904 COVID19+ patients as of March 16, 2020. 3 Given its rapid spread and 3.4% mortality rate, 4 countries like Italy and China have been forced to ration limited healthcare resources, and there are concerns that the US may need to do so as well. 5 Person-to-person transmission by asymptomatic individuals and pre-symptomatic individuals during the up-to-14 day incubation period 6 may play a significant role in this pandemic. [7] [8] [9] [10] Infection transmission between COVID-19 patients and healthcare workers has also been documented. 11 Given the current status of the COVID-19 outbreak, the US Surgeon General, 12 Centers for Disease Control and Prevention (CDC), 13 American College of Surgeons (ACS), 14 American Society of Anesthesiologists (ASA), and Anesthesia Patient Safety Foundation (APSF) 15 have recommended considering rescheduling or postponing some elective surgeries with the goal of conserving limited resources, such as ventilators and ICU beds, and mitigating the risk of "exposing other inpatients, outpatients, and health care providers to the risk of contracting COVID-19" from asymptomatic but infectious patients. 14 However, the American Hospital Association, the Federation of American Hospitals, the Association of American Medical Colleges, and the Children's Hospital Association have written a joint letter opposing the surgeon general's advice. 12 Multiple hospitals, including several major hospital systems in WA, are canceling or postponing elective surgery procedures, 16, 17 but there are other hospitals that have declared they will proceed with elective cases. 18 The goal of this study is to provide a quantitative analysis and model for preventable COVID-19 infections from elective outpatient or ambulatory surgery cases. Our model can also be adapted to analyze COVID-19 transmission in other healthcare settings. Furthermore, given the controversy over the appropriate handling of elective surgical cases during this pandemic, we hope that our results may have a positive impact on health policy and public health. Given much of the uncertainty regarding the pathophysiology and epidemiology of COVID-19, and the potential policy implications of our results, we chose to focus on lower bounds for preventable infections instead of upper bounds.