CANTON, Mass. (UPI) -- A survey commissioned by Massachusetts-based Dunkin' Donuts ahead of National Coffee Day indicates scientists have the most need for coffee in their workdays.

The online survey of 4,700 U.S. workers, which was jointly commissioned by Dunkin' Donuts and Web site CareerBuilder ahead of Thursday's National Coffee Day, found 34 percent of respondents said they need coffee to get through their workdays and 46 percent of those said they are less productive without coffee.

The survey found scientists and lab technicians were the most likely to say they were less productive without coffee, followed by marketing and public relations professionals, education administrators, editors and writers, healthcare administrators and physicians.

"National Coffee Day is the perfect time to celebrate coffee's unique place as a staple in our daily lives," said John Costello, chief global customer and innovation officer at Dunkin' Brands. As these survey results show, coffee continues to play an increasingly important role in the workplace, helping to jumpstart people across all professions in the morning and keep them going throughout their busy workday.

The survey, conducted Aug. 16 through Sept. 8, had a plus or minus 1.43 percentage margin of error with a 95 percent certainty.

Copyright 2011 by United Press International