Over- and under-estimation of COVID-19 deaths

Abstract

The ratio of COVID-19-attributable deaths versus “true” COVID-19 deaths depends on the synchronicity of the epidemic wave with population mortality; duration of test positivity, diagnostic time window, and testing practices close to and at death; infection prevalence; the extent of diagnosing without testing documentation; and the ratio of overall (all-cause) population mortality rate and infection fatality rate. A nomogram is offered to assess the potential extent of over- and under-counting in different situations. COVID-19 deaths were apparently under-counted early in the pandemic and continue to be under-counted in several countries, especially in Africa, while over-counting probably currently exists for several other countries, especially those with intensive testing and high sensitization and/or incentives for COVID-19 diagnoses. Death attribution in a syndemic like COVID-19 needs great caution. Finally, excess death estimates are subject to substantial annual variability and include also indirect effects of the pandemic and the effects of measures taken.

Change in age distribution of COVID-19 deaths with the introduction of COVID-19 vaccination

“…These changes may represent changes in the documentation of COVID-19 deaths, especially among the elderly, e.g. more deaths missed in 2020 due to insufficient testing ( Ioannidis, 2021a ) – or other data artefacts.…”

Analysis of Fatality Impact and Seroprevalence Surveys in a Community Sustaining a SARS-CoV-2 Superspreading Event

“…This over-estimation of COVID-19 deaths is similar to the rates seen in audits in US counties 10,11 . Over-estimation of COVID-19 deaths may apply also to other settings, especially in high-income countries where intensive testing is performed 9 .…”

“…Two main concerns are whether the surveyed sample is representative of the general population and whether people who get infected do not develop or lose their detectable antibodies over time. The validation of the number of COVID-19-related deaths has received less attention, but both over-and under-counting may occur 9 . COVID-19 deaths may have been underestimated in particular in some locations at the beginning of the pandemic when testing was limited, or because determining the cause of death (COD) in the elderly or those with multiple comorbidities was difficult.…”

Complexity of COVID-19 Dynamics

“…These can have serious implications for our efforts to prevent, treat, and control the spread of COVID-19, reduce the loss of life, mitigate social and personal problems arising from COVID-19, and save our economy. For instance, low COVID-19 testing can result in the undercounting of cases and deaths in the majority of nations around the world, as has been reported by many studies [ 68 , 69 , 70 , 71 ]. Various factors can contribute to low COVID-19 testing, including economic resources, human resources, individual and societal health awareness, and political stability and will.…”