Study examines the association of dementia diagnosis with risk of COVID-19 mortality

Since December 2019, more than 60 million people have been diagnosed with coronavirus disease 2019 (COVID-19) worldwide, and about six million people have died from the disease. About 10%-20% of COVID-19 patients required hospital treatment, with this proportion decreasing over time. Several studies have shown the impact of dementia on mortality in COVID-19 patients, however, most studies were conducted in the first months of the COVID-19 pandemic.

The purpose of this research to be published in the next issue Journal of Alzheimer’s Diseasewas to verify the association of dementia diagnosis with the risk of death due to COVID-19 among patients treated during the pandemic in several large hospitals in Germany.

The effects of dementia on mortality from COVID-19 may have changed over time, particularly after vaccines became available and widely administered and as different variants of SARS-CoV-2 evolved. Given these factors, it is important to carry out studies that include patients diagnosed with COVID-19 during the long period of the pandemic.”

Prof. Karel Kostev, PhD, Department of Epidemiology, IQVIA

This retrospective study was performed and analyzed by the Asklepios hospital group. It was based on anonymized electronic medical data from public health service hospitals throughout Germany. It included 28,311 patients with a confirmed diagnosis of COVID-19 who were hospitalized between March 11, 2020, and July 20, 2022. For this study, demographic data (age, sex), relevant COVID-19 data (ventilation, mortality), time of COVID. -19 diagnosis, and codiagnosis data were used.

The main result of the study was that a diagnosis of dementia was associated with an increased risk of death during hospital stay. The relationship between dementia and death was analyzed with multivariable logistic regression adjusted for age, sex, cancer, diabetes mellitus, lipid metabolism disorder, obesity, heart failure, ischemic heart disease, cerebrovascular disease, liver cirrhosis and probable variant of COVID-19. . Univariate conditional logistic regression was performed for matched pairs to examine the association between dementia and death.

Of the 28,311 patients diagnosed with COVID-19, 3,317 (11.3%) were diagnosed with dementia. Before matching, 26.5% of dementia patients and 11.5% of non-dementia patients died; the difference was smaller in matched pairs, where 26.5% of dementia patients and 21.3% of non-dementia patients died.

In multivariate logistic regression, dementia was associated with an 84% (OR=1.84; 95% CI: 1.52–2.24) increased risk of death. In univariate logistic regression for matched pairs, dementia was associated with a 33% (OR=1.33; 95% CI: 1.16–1.53) increased risk of death.

“Dementia was associated with an increased risk of mortality, but the association was weaker than reported in most previous publications,” said Dr. Marc Axel Wollmer PD, director of the department of gerontopsychiatry at Asklepios Hospital Nord-Ochsenzoll. Hamburg “To the authors’ knowledge, this is one of the first studies to investigate the association between dementia and mortality from COVID-19 using data collected over two years and applying two different statistical methods in parallel.”

The authors of the study also point out that “Although SARS-CoV-2 has changed over time and the vaccine has generally greatly improved the prognosis of people who contract COVID-19, more research is needed to identify risk factors, prevent and treat death from this disease”.

The two main strengths of this study are the large sample size (n=28,311) and the inclusion of patients diagnosed with COVID-19 during a long pandemic period from March 2020 to July 2022. However, our study is also subject to several limitations. the limits There is no specific information about the causes of death of these deceased patients. Most, but not all, of the death cases listed COVID-19 as the primary cause of death. In addition, there are no drugs used for the therapy of COVID-19 and no other drugs have been studied. Information on the vaccination status of the patients included in the study was missing. Although Germany has a very high COVID-19 vaccination rate among its elderly population, the period of this study included the year 2020 when there was no vaccine. Data on socioeconomic status (eg, education and income) and lifestyle-related risk factors (eg, smoking, alcohol consumption, and physical activity) are also lacking. These possible confounders could not be matched in our analysis, which would have been desirable.