THURSDAY, May 1 (HealthDay News) -- Not having money hurts. Physically.

Lower-income Americans experience pain much more frequently than those making more money, according to a study that had nearly 4,000 people keep a diary in which they scored their feelings of pain on a scale of 0 to 6 for randomly selected 15-minute intervals.

People with household incomes below $30,000 a year reported moderate to severe pain 20 percent of the time. Those making more than $100,000 a year said they experienced pain less than 8 percent of the time.

"The arrows point in both directions," said study co-author Alan Kreuger, a professor of economics at Princeton University, explaining the findings reported in the May 3 issue of The Lancet. "First, people with lower skills tend to do more physically demanding labor, and that leads to pain. Secondly, people who have a lot of pain in their lives find it hard to work."

Education also affected pain results. People with less than a high school degree reported twice the average pain rating through the day as those with college degrees, the study found.

The pain study was an extension of work done in association with Arthur Stone, a professor of psychiatry and behavioral science at Stony Brook University in New York, Kreuger said. "We had been doing work on how people used their time and how they felt about it, and decided to add questions about pain to this national survey," he said.

The link between pain and lower income and socioeconomic status wasn't necessarily a surprise, Krueger said. "We sort of expected to find that," he said. "But there was a much stronger relationship than I expected."

The nature of someone's work had a strong influence on the experience of pain. Blue-collar workers reported higher rates of pain and more severe pain than those with desk jobs. And the 13 percent of people with work-related disabilities accounted for 44 percent of the time Americans spent in moderate to severe pain, the study found.

Some other survey findings were predictable. People were more likely to feel pain while alone, and those with pain spent almost 25 percent of their time watching television, compared to 16 percent for those experiencing less discomfort.

And people felt more pain as they grew older, with the average pain rating increasing with the years. But there was a surprising temporary plateau between the ages of 45 and 75, after which pain increased, the study found.

The fact that the pain imbalance persists after the working years indicates that "more attention should be paid to economics and health-care services," said Juha H.O. Turunen, a professor of social pharmacy at the University of Kuopio in Finland, who wrote an accompanying editorial in the journal.

"Studies over the years have shown that people with less education and low income suffer from more pain," Turunen said. "Their work environment is different, and they are not as interested in taking care of their health. Life habits are associated with economic status."

One notable finding of the survey was that people responsible for the care of others reported very high pain scores, Turunen said. "Attention should be paid by society," he said. But, he added, he'd avoid making recommendations about the United States because of his unfamiliarity with America's health-care system.

More information

If you really want to read more about pain, consult the U.S. National Library of Medicine.

SOURCES: Alan Kreuger, Ph.D., professor, economics, Princeton University, Princeton, N.J.; Juha H.O. Turunen, D.Pharm, professor, social pharmacy, University of Kuopio, Finland; May 3, 2008, The Lancet

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