According to Aviva, 2.31 million UK workers called in sick after drinking too much or having an accident at a work Christmas party last year resulting in £216 million lost to the British economy, based on CBI calculations of absence costs.
Men are more than twice as likely as women (88% more likely) to call in sick after the office party, and directors and managers are significantly more likely (67% more likely) to call in sick than the rest of the workforce.
Despite the recession, almost two thirds (61%) of UK businesses are still planning a party and workers' festive spirit have not been dampened - over a quarter (26%) say the stresses of 2009 mean people are likely to get more drunk than usual.
Employees will drink on average 7.3 units of alcohol at their Christmas party; men plan to drink an average of 9.6 units, nearly three times the recommended limit for men of 3 to 4 units per day. Women say they are likely to drink an average of 5.6 units -well over twice the recommended daily limit of 2 to 3 units.
And alcohol-related accidents at Christmas parties are rife, with nearly a third (31%) resulting in hospital treatment.
A third (33%) of workers are honest about the reason for absence, while those who use illness as an excuse are most likely to claim flu (23%). Other popular excuses include food poisoning and migraines.
Doug Wright, principal clinical consultant at Aviva UK Health, said: "After what has been a stressful year for many, it's understandable people want to let their hair down this Christmas.
"However, with 15% of people claiming to have witnessed or experienced accidents at the office parties, it pays to stay sober enough so as not to risk injury. Don't drink on an empty stomach and try alternating alcohol with soft drinks to avoid an unwanted trip to A&E during the festive period.
"For the 2 million people who could be tempted to call in sick ‘the morning after' we'd suggest booking a day off to recuperate - otherwise people may find they face more than a hangover"
The most common office party mishaps are:
1 Falling over dancing
2 Slipping on spilt drinks
3 Falling off furniture / a stage
4 Passing out
5 Walking into a wall / object