By Kathleen Doheny

SAN DIEGO, CA (Reuters Health) Aug 21 - Pain from common conditions such as backache costs U.S. employers about $80 billion a year in lost productivity, according to a report presented here at the 10th World Congress on Pain.

The bulk of the loss, about $64 billion, occurs not when workers take sick days but rather when they are on the job but in too much pain to perform up to par, the researchers reported.

The survey is "the first to really measure the cost of pain," lead author Walter Stewart, a researcher at the Center for Work and Health at AdvancePCS, in Hunt Valley, Maryland, told Reuters Health. AdvancePCS provides information on health improvement services.

To arrive at the estimate, the researchers conducted an ongoing telephone survey, from July 2001 to July 2002, including more than 29,000 employed subjects and more than 1600 unemployed (to compare pain prevalence) ranging from 18 to 65 years old. They described pain complaints from headache, arthritis, backache and other musculoskeletal conditions as well as work absences and reduced work performance.

The researchers converted the subjects' lost productive time to dollars per worker per week, using self-reported annual salary and then extrapolating to the U.S. workforce as a whole.

"I was surprised at how pervasive pain is," said Judith Ricci, another member of the research team. "Over half the people we interviewed who were working reporting being in pain at least once in the past two weeks." In fact, pain appears to be the most prevalent medical condition in the U.S. work force and the most costly in terms of lost productivity.

Headache and back pain accounted for the majority of pain complaints. Pain has the most impact on the job for men, those 35 to 40 years, those with less education, African Americans and workers with high demand jobs over which they have little control.

"The critical finding here is that pain is common in the workforce," Stewart said. "People bring it to work and they don't function well. And it's invisible to employers."

Stewart suggested that employers who have a significant number of employees with pain problems might decide to devote more of their healthcare dollars to pain management classes than, say, wellness programs.