Which of the following factors can affect an individual's fitness for duty?

An individual's fitness for duty is primarily impacted by their physical health, mental health, and substance use. These factors directly influence a person's ability to perform effectively in their role. For instance, physical health affects energy levels, stamina, and the ability to handle the demands of a job, while mental health can influence focus, decision-making, and emotional stability. Additionally, substance use can severely impair judgment, coordination, and overall job performance.

These factors are crucial in assessing whether an employee can safely and competently fulfill their responsibilities, making them the most significant contributors to fitness for duty evaluations. Other factors, such as programming skills, length of service, and education level, may play a role in job performance but are not essential for basic fitness for duty assessments. They relate more to job proficiency and experience rather than the fundamental capability to perform safely and effectively in the workplace.