The costs of an expanded screening criteria for COVID-19: A modelling study

Nosocomial infection is an ongoing concern in the COVID-19 outbreak. The effective screening of suspected cases in the healthcare setting is therefore necessary, enabling the early identification and prompt isolation of cases for epidemic containment. We aimed to assess the cost and health outcomes of an extended screening strategy, implemented in Singapore on 07 February 2020, which maximizes case identification in the public healthcare system.

We explored the effects of the expanded screening criteria which allow clinicians to isolate and investigate patients presenting with undifferentiated fever or respiratory symptoms or chest x-ray abnormalities. We formulated a cost appraisal framework which evaluated the treatment costs averted from the prevention of secondary transmission in the hospital setting, as determined by a branching process infection model, and compared these to the costs of the additional testing required to meet the criteria.

In the base case analysis, an R₀ of 2.5 and incubation period of 4 days, an estimated 239 (95% CI: 201-287) cases could be averted over 150 days within the hospital setting through ESC. A corresponding $2.36 (2-2.85) million USD in costs could be averted with net cost savings of $124,000 (95% CI: -334,000 to 516,000). In the sensitivity analyses, when positive identification rates (PIR) were above 7%, regardless of R₀ and incubation period, all scenarios were cost-saving.

The expanded screening criteria can help to identify and promptly isolate positive COVID cases in a cost-saving manner or within acceptable cost margins where the costs incurred from the testing of negative patients could be negated by the averted costs. Outbreak control must be sustainable and effective; the proposed screening criteria should be considered to mitigate nosocomial transmission risk within healthcare facilities.