Effect of fasting duration on mortality after COVID-19 infection: A retrospective analysis at a single institution

The fasting duration in aspiration pneumonia negatively affects the patient's treatment duration and swallowing function. The relationship among serious COVID-19 infection, fasting duration, and patient prognosis remains unclear. We aimed to determine the effect of the fasting duration on mortality after COVID-19.

We included patients who underwent rehabilitation after COVID-19 infection between March 1, 2021 and June 30, 2023. We retrospectively extracted data from medical records, including age, sex, albumin levels, fasting duration, Charlson Comorbidity Index (CCI), Revised Hasegawa Dementia Scale score, care level, total hospitalization period, time since disease onset, time to speech therapy intervention, time to death, and ability to eat at disease onset and discharge. Univariate analysis was conducted for each variable. To investigate the relationship between fasting duration and outcomes, we performed logistic regression analysis, adjusting for confounding factors such as age, CCI, and care level. We also divided patients into groups based on fasting duration: ≤ 5 days and > 5 days. We performed logistic regression analysis using fasting duration as the dependent variable and age, CCI, care level, and clinical outcome as independent variables.

There were 71 patients in the survival group and 31 in the mortality group. Fasting duration (p = 0.00826, odds ratio [OR]: 1.01, 95 % confidence interval [CI]: 1.01-1.11) and age (p = 0.0377, OR: 1.07, 95 % CI: 1.001-1.15) were significant independent factors associated with COVID-19 outcomes. In the classification based on fasting duration, higher care level (p < 0.001, OR: 1.65, 95 % CI: 1.24-2.20) and clinical outcome (p < 0.001, OR: 9.19, 95 % CI: 2.80-30.20) were significant independent factors in the group with fasting duration > 5 days.

Fasting duration was independently associated with outcomes after COVID-19 infection. Early rehabilitation intervention may contribute to improved clinical outcomes.