A recent report posted to the medRxiv* preprint server examined the health influences of long coronavirus disease (COVID) during the 2021 to 2022 severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Omicron surge in Australia.
A subset of acute SARS-CoV-2 survivors have been documented to experience long COVID symptoms; the risk is higher for COVID 2019 (COVID-19) non-vaccinated individuals and those who experienced more severe acute infections. A diverse combination of symptoms that continue or appear following acute COVID-19 for at least 12 weeks is known as long COVID.
It is crucial to estimate the full health implications of COVID-19, including its long-term effects, given the persistently high frequencies of SARS-CoV-2 spread worldwide. Prior studies estimated the health loss caused by long COVID across the population from 2020 to 2021, utilizing current health states to describe this range of outcomes. Although these health states share some symptoms with the recorded long COVID symptoms, they do not account for the entire range of symptoms associated with long COVID or the variety of symptoms described by different people.
About the study
In the current research, the scientists aimed to analyze the influence of long COVID on deaths during the SARS-CoV-2 Omicron surge from 2021 to 2022 across Australia compared to the acute COVID-19 mortality and morbidity and other sources of mortality and morbidity in Australia. They used data from priorly published population-based cross-sectional, case-control, or cohort analyses to conduct the burden of disease study.
Initially, the team determined the magnitude of the morbidity associated with long COVID caused by the SARS-CoV-2 Omicron variant infections regarding frequency, severity, and duration. Secondly, they assessed how much of the total disability-adjusted life years (DALYs) accrued in Australia during the 2021 to 2022 Omicron wave were attributable to long COVID and how this health loss compares to other significant causes of disability in the nation.
The study subjects were individuals with symptomatic SARS-CoV-2 infection from 10 December 2021 to 9 April 2022. The primary research outcomes measured were years lived with disability (YLDs) from long COVID and acute COVID-19. They were estimated from the duration, severity, and prevalence of each long COVID symptom as determined from prior reports, summed throughout all long COVID symptoms, and applied to the group of SARS-CoV-2 surviving cases across Australia during the 2021 to 2022 Omicron surge. Furthermore, total COVID-19 DALYs were estimated to be produced by acute COVID-19 YLDs and years of life lost (YLLs) from COVID-19 fatalities.
According to the study results, 5,300 YLDs were due to long COVID during the Omicron surge across Australia, contributing to 74% of all YLDs from SARS-CoV-2 infections. In the four-month timeframe of the research, COVID-19 was responsible for 51,000 DALYs overall, or 2.4% of all DALYs. This inference was similar to the health loss brought on by drug use and dementia disorders.
The highest contribution to the total uncertainty across long COVID morbidity was associated with severity estimations, according to one-way sensitivity analyses performed on each morbidity variable. This observation was concerning, given that the bulk of disability weights (DWs) employed were calculated using estimates from other health states and were applied uniformly across sub-groups. In addition, despite making up a minor fraction of the total symptoms incorporated in the assessment, psychological and cognitive symptoms contributed to a high degree of uncertainty across overall estimates, highlighting the requirement for additional studies on the severity and prevalence of these symptoms.
Notably, the true YLLs of many COVID-19 fatalities will be lower than those determined using conventional DALY techniques.
The authors claimed that the present study was the first to thoroughly quantify long COVID morbidity in Australia during the Omicron wave from 2021 to 2022, broken down by each symptom.
The study findings showed that long COVID was responsible for nearly three-fourths of the non-fatal health losses brought on by Omicron variant infections. The team stated that long COVID demands consideration in the SARS-CoV-2 pandemic policy designing, considering that it accounted for the bulk of COVID-19-associated overall morbidity loss, even in an Omicron surge among a highly vaccinated community. Further, a more precise assessment of long COVID morbidity will be possible with additional investigations of the symptom pattern, duration of long COVID after Omicron infection, and more reliable severity evaluations.
medRxiv publishes preliminary scientific reports that are not peer-reviewed and, therefore, should not be regarded as conclusive, guide clinical practice/health-related behavior, or treated as established information.