Modelling the potential acute and post-acute burden of COVID-19 under the Australian border re-opening plan.

Background: Concerns have grown that post-acute sequelae of COVID-19 may affect significant numbers of survivors. However, the analyses used to guide policy-making for Australia's national and state re-opening plans have not incorporated non-acute illness in their modelling. We, therefore, develop a model by which to estimate the potential acute and post-acute COVID-19 burden using disability-adjusted life years (DALYs) associated with the re-opening of Australian borders and the easing of other public health measures, with particular attention to longer-term, post-acute consequences and the potential impact of permanent functional impairment following COVID-19.

Methods: A model was developed based on the European Burden of Disease Network protocol guideline and consensus model to estimate the burden of COVID-19 using DALYs. Data inputs were based on publicly available sources. COVID-19 infection and different scenarios were drawn from the Doherty Institute's modelling report to estimate the likely DALY losses under the Australian national re-opening plan. Long COVID prevalence, post-intensive care syndrome (PICS) and potential permanent functional impairment incidences were drawn from the literature. DALYs were calculated for the following health states: the symptomatic phase, Long COVID, PICS and potential permanent functional impairment (e.g., diabetes, Parkinson's disease, dementia, anxiety disorders, ischemic stroke). Uncertainty and sensitivity analysis were performed to examine the robustness of the results.

Results: Mortality was responsible for 72-74% of the total base case COVID-19 burden. Long COVID and post-intensive care syndrome accounted for at least 19 and 3% of the total base case DALYs respectively. When included in the analysis, potential permanent impairment could contribute to 51-55% of total DALYs lost.

Conclusions: The impact of Long COVID and potential long-term post-COVID disabilities could contribute substantially to the COVID-19 burden in Australia's post-vaccination setting. As vaccination coverage increases, the share of COVID-19 burden driven by longer-term morbidity rises relative to mortality. As Australia re-opens, better estimates of the COVID-19 burden can assist with decision-making on pandemic control measures and planning for the healthcare needs of COVID-19 survivors. Our estimates highlight the importance of valuing the morbidity of post-COVID-19 sequelae, above and beyond simple mortality and case statistics.