Risk Of Death, Disability Greater In Months After Flu Infection, Study Says

(Photo : Getty Images/Johan Nilsson)

A recent study has indicated that the risk of death and disability is greater in months after flu infection.

According to experts, this is similar to those who have experienced long COVID-19.

Risk Of Death, Hospital Readmission

They said that previous comparative analyses of people admitted to hospital for COVID-19 versus influenza had evaluated the risk of death, hospital readmission, and a narrow set of health outcomes up to six months following infection.

Researchers aimed to do a comparative evaluation of both acute and long-term risks and burdens of a comprehensive set of health outcomes following hospital admission for COVID-19 or seasonal influenza.

In the conduct of the study, researchers used the health-care databases of the US Department of Veterans Affairs to analyze the data from 81,280 participants admitted to hospital for COVID-19 between March 1, 2020, and June 30, 2022, and 10,985 participants admitted to hospital for seasonal influenza between Oct 1, 2015, and Feb 28, 2019.

The participants were followed up for up to 18 months to comparatively evaluate risks and burdens of death, a prespecified set of 94 individual health outcomes, ten organ systems, overall burden across all organ systems, readmission, and admission to intensive care.

Furthermore, inverse probability weighting was used to balance the baseline characteristics.

Cox and Poisson models were used to generate estimates of risk on both the relative scale and absolute scale as the event rate and disability-adjusted life-years (DALYs) per 100 persons.

In the comparative analysis of long-term health outcomes of people admitted to hospital for COVID-19 versus those admitted to hospital for seasonal influenza, researchers found out that the absolute rates of death, adverse health outcomes, and health-care utilization are high for both viruses, but significantly higher for COVID-19 compared to seasonal influenza.

The analyses of health burden by organ system showed differential risks across organ systems, with a higher burden of pulmonary organ involvement in seasonal influenza and a higher burden of extrapulmonary organ involvement in COVID-19.

Moreover, the decomposition analyses reveal two key findings: both SARS-CoV-2 infection and seasonal influenza result in a higher burden of health loss in the post-acute phase than their respective acute phases; and SARS-CoV-2 results in a higher burden of health loss in both the acute and post-acute phase than seasonal influenza.

Post-Acute Care

Altogether, these findings emphasized the high toll of death, health loss, and health-care utilisation following hospital admission for seasonal influenza and even a higher toll for SARS-CoV-2.

It also highlighted the continued need to reduce the risk of hospital admission for these two viruses as a means to alleviate the burden of health loss in populations.

On the other hand, the experts' observation suggested the need for provision of post-acute care following hospital admission for either COVID-19 or seasonal influenza, and that this need is likely to be greater for COVID-19.

Experts pointed out that post-acute care will not only facilitate the management of post-acute sequelae but could also improve health outcomes and reduce the need for costly health-care utilization, such as repeat hospital admissions and intensive care.

In summary, the burden of death, health loss, and health-care utilization is high among those admitted to hospital for seasonal influenza, but higher among those admitted to hospital for COVID-19 in the pre-delta, delta, and omicron eras.

The risk of pulmonary involvement is higher in seasonal influenza while the risk of extrapulmonary organ system involvement is higher in COVID-19.