There’s a good chance that someone in your office is drinking on the job — and it’s affecting your company’s bottom line.

One of the biggest drains on productivity these days is “presenteeism,” when employees come to work despite being ill or having personal issues, and instead of focusing on their work they are distracted and unproductive. By some estimates, the average worker loses 115 productive hours per year to presenteeism, costing employers billions of dollars. That’s not even accounting for the costs associated with treating health problems related to drinking too much.

While illness and personal stress are major factors in presenteeism, one of the biggest contributors is substance abuse, specifically alcohol. In fact, a study in the Journal of Studies on Alcohol and Drugs showed that as many as 15 percent of the U.S. workforce — 19.2 million workers — has been impaired by alcohol while on the job, either because of drinking on the job or suffering the effects of drinking too much while off the clock.

One Drink or 10, It’s All the Same

The JSAD investigation, conducted by Michael Frone at the State University of New York, Buffalo, was a phone survey of 2,800 randomly selected adults. The survey questions dealt with the respondents’ alcohol use as it related to their work; specifically, the survey asked how often adults drank alcohol within two hours of starting work or during work, how often they worked while under the influence of alcohol or came to work with a hangover during the previous 12 months. In general, white, unmarried men were more likely to report drinking on the job, as were those who don’t work a regular 9-to-5 schedule.

Specifically, the study found the largest number of respondents drank during the workday or came to work with a hangover. According to the report, approximately 7 percent of the workforce has used alcohol during the workday, and 9 percent has come to work with symptoms of a hangover. It should be noted, though, that the study defined workday alcohol use as any type or amount of alcohol at any point during the day. That means respondents who had an occasional glass of wine during a client lunch or came to work with a hangover the day after the Super Bowl were counted, even if they were isolated examples or company-sanctioned drinks.

While it might appear that the general workforce is coming to work tipsy, the survey also indicated that 70 percent of those who reported alcohol use on the job only indulge occasionally, meaning less than monthly. Only 11 percent of those who admitted to workday alcohol use reported doing so weekly. But again, a large number of people report coming to work hung over, which in some cases impairs productivity as much as actually being drunk.

The journal’s report may have offered startling statistics about the prevalence of alcohol in the workplace, but it did not delve into the reasons why employees opt to drink at work or have a few too many when they know they have to work the next day.  But regardless of the reasons, it’s clear that alcohol is causing problems in the workplace, not the least of which are the lost productivity and revenue caused by drunk or hung-over employees.