This study aimed to investigate the evolution of burnout levels and cardiovascular risk among healthcare professionals during the COVID-19 pandemic, identifying associated risk factors, with a particular focus on the impact of working hours, job roles and working units.

A longitudinal, observational study was conducted.

The study was carried out in a medical centre in central Taiwan, encompassing various healthcare settings.

A total of 1502 healthcare workers participated, including nurses, medical technicians, resident doctors, attending physicians and administrative staff. Participants were selected based on consistent completion of a 4-year questionnaire, with exclusion criteria for those who did not complete.

The primary outcome measured was burnout levels using the Chinese version of the Copenhagen Burnout Inventory. The secondary outcome was cardiovascular risk calculated from employees’ health check-up data using the Framingham Risk Score.

Cardiovascular risk showed an upward trend over 4 years. Personal and work-related burnout significantly decreased from 2019 to 2020 but increased from 2020 to 2022, aligning with changes in weekly working hours. Nurses exhibited the most pronounced fluctuations, likely due to their younger average age, shorter professional tenure and frequent direct patient contact, which may heighten vulnerability to pandemic-related stressors. In contrast, attending physicians demonstrated age as a protective factor against burnout, as greater seniority, clinical experience and professional maturity may buffer stress and foster resilience. Participants who worked in COVID-related units generally had elevated burnout levels and working hours. During the initial outbreak in 2020, employees working in COVID-related units had reduced working hours but stable burnout levels, while employees in non-COVID-related units experienced decreased burnout.

This study highlights the critical impact of long working hours on burnout among healthcare professionals during the COVID-19 pandemic. Nurses emerged as a vulnerable group, sensitive to pandemic-induced changes, while attending physicians exhibited more resilience. COVID-related units face greater stress and are less likely to benefit from reductions in patient numbers and working hours during the pandemic. Our findings underscore the urgent need for tailored interventions, such as regulated work hours, flexible scheduling and enhanced organisational and peer support, to protect healthcare workers’ well-being. These strategies can strengthen workforce resilience and sustainability in future public health crises.