This study investigated absenteeism among nursing staff (nursing assistants, nursing technicians, and nurses) during the COVID-19 pandemic, aiming to compare rates and associated factors across different professional categories. Using a simulated dataset, informed by real-world data and scientific literature, advanced statistical analyses were applied, including Student’s t-test, ANOVA, Linear Regression, Pearson’s Correlation, and Chi-square test. Results indicated significant differences in absenteeism rates among categories, with nursing technicians showing the highest average number of days absent. Age and length of service also correlated with absenteeism. The discussion addresses the implications of these findings for healthcare human resource management and the need for specific support strategies for each professional category, aiming to mitigate the impact of absenteeism on care quality and healthcare service sustainability. It is concluded that the pandemic exacerbated pre-existing challenges, demanding targeted interventions for the health and well-being of the nursing team.