The findings were based on a telephone survey of 3,982 U.S. citizens, 15 years old and older, who reported their activities and the occurrence and intensity of pain in a diary over a 24-hour period. They were asked to rate their pain on a scale of 0 to 6.

The research also found strong connections between the experience of pain and levels of income and education.

"Those with lower income or less education spent a higher proportion of time in pain and reported higher average pain than did those with higher income or more education," Princeton economist Alan Krueger, who authored the study along with Dr. Arthur Stone, a psychiatry professor at Stony Brook University in New York wrote in their study.

The survey found that 29 percent of men and 27 percent of women reported feeling some pain during the sample time. The findings are not new, as previous studies found that 17 percent to 29 percent of the general population suffers chronic pains, commented Juha H.O. Turunen, Ph. D., of the University of Kuopio, Finland, in an accompanying editorial.

Education was a strong predictor of pain. Participants with less than a high school diploma had an average pain rating twice that of college graduates.

Also, men and women in households with yearly income below $30,000 were twice as likely to have pains compared with those having an annual income of more than $100,000. Moreover, people in the lowest income category spent 34.2 percent of their time in some degree of pain and 18.5 percent of their time in more severe pain. Those proportions were 22.9 percent and 7.7 percent for those in the highest income category.

The study also found that disability and lack of satisfaction with life and health status were associated with the highest pain levels.

Additionally the researchers wrote: “The average pain rating increased with age, although it reached a plateau between ages of about 45 years and 75 years, with little difference between men and women. Satisfaction with life or health and the pain indicators tended to move in opposite directions.”

Krueger and Stone go even further and analyze the loss registered by the U.S. economy due to these pains, finding an estimated $60 billion a year in lost productivity. They found that Americans spent about $2.6 billion in over-the-counter pain medications and another nearly $14 billion on outpatient analgesics in 2004, the most recent data available.

“In addition to being viewed as a pathological problem, our data suggest that pain should also be viewed as an (economic) and social burden,” Krueger and Stone wrote in the study.

In the accompanying editorial, Prof. Turunen said the study may have broad implications for policymakers, suggesting that more pain prevention measures may be needed in the workplace or assistance offered to adults who report pain while caring for family members.

“I hope that more studies like this will help to find ways of identifying subgroups needing help with their pain, for example to enable pain sufferers to obtain quicker and easier access to multidisciplinary pain clinics,” Prof. Turunen said.

The study, funded by the U.S. National Institute of Aging and the Hewlett Foundation, appears in the May 3 issue of The Lancet.