16 % of employers have fired a worker for missing work without a legitimate excuse, according to an annual survey by CareerBuilder.com

Thirty-two percent of workers said they have called in sick when they were well at least once in the last year, according to an annual survey on absenteeism at the office.

And while the majority of employers (75 %) said they typically believe excuses given by employees, 35 % reported they have checked up on an employee who called in sick and 16 % said they have fired a worker for missing work without a legitimate excuse.

The survey included 5,989 workers and 2,929 hiring managers and human resource professionals.

Twenty-seven percent of workers said they consider their sick days to be equivalent to vacation days and one-in-ten admitted to playing hooky three times or more even though they were feeling well. One-in-five workers (23 %) said they took the day off simply because they just didn't feel like going to work that day. Fifteen percent missed work because they needed to relax, 11 % had a doctor's appointment, 9 % wanted to catch up on sleep and another 9 % had plans with family and friends.

More than half (52 %) of employers say Monday is the most popular day for employee absenteeism, followed by Friday at 24 % and Saturday at 9 %. Of the 35 % of employers who checked up on an employee who called in sick, 67 % said they required the employee to show them a doctor's note. Fifty-nine percent called the employee at home, 16 % had another worker call the employee, and 14 % drove by the employee's house or apartment.

While some employers are more skeptical of certain absences, others are incorporating more flexibility into their sick day programs. Sixty-nine percent of employers said they allow their team members to use sick days for mental health days, according to the research.

Rosemary Haefner, vice president of human resources at CareerBuilder.com, said: "Employers are placing a greater emphasis on work/life balance, offering more opportunities for employees to recharge and return to the office more productive. Your best bet is to be honest. If you're a strong employee and you're truthful about the time you need off, your employer is likely to give it to you. Lying about it, on the other hand, can have a lasting, negative impact on your credibility and job tenure."