TUESDAY, Feb. 10 (HealthDay News) -- A North Carolina study finds that the rate of chronic low back pain has more than doubled in that state since the early 1990s -- a statistic the authors say might reflect what's happening in the country as a whole.
"We were actually surprised by what we found," said Dr. Timothy S. Carey, a professor of medicine at the University of North Carolina and the study's lead author.
He said his team knew that expenditures for medical services aimed at easing back pain have increased over the years. One theory for that rise has been that back pain sufferers are simply seeking more services.
But the researchers found another cause.
"A major reason for the increase in cost for back pain is not just that people are seeking a lot of care, but that there is a lot of back pain out there," Carey said. "We may need to rethink our way of dealing with this problem."
According to the study, 3.9 percent of North Carolina residents surveyed in 1992 said that they had debilitating, chronic back pain. That number rose to 10.2 percent by 2006, the researchers said.
Among people reporting ongoing, serious low back pain in 1992, about 73 percent said they had seen a physician, physical therapist or chiropractor at least once during the past year. In 2006, 84 percent said they had done so. However, the average number of health care visits remained the same, at just 19 a year.
The fraction of people with back pain who had ever had back surgery increased only slightly, from 22.3 percent in 1992 to 24.8 percent in 2006.
The findings were published in the Feb. 9 issue of Archives of Internal Medicine.
The methodology of the study didn't enable researchers to ascertain the reasons for the increase in chronic lower back problems, but there are several possibilities, Carey said. One is the increase in obesity. Another is an increase in the prevalence of depression, which has been linked to back pain. Carey said that it's unclear whether back pain causes depression or whether people with pre-existing depression are more likely to develop depression.
What is clear is that chronic lower back problems remain a major public health problem.
"While no one dies from mechanical back pain, it is one of the most common reasons for work disability," Carey noted. The bill for lost productivity and back-related health care totals about $100 billion a year, he added. "In one sense, we're all paying for back pain. It ends up being reflected in our health insurance premiums and our Social Security disability costs," he said.
Carey said there appears to be a national trend toward increasing numbers of people with chronic lower back pain that causes impairment. The National Health Interview Survey showed that lower back pain and neck pain increased from 3.2 percent of the population in 1997 to 8.3 percent in 2006.
"There's not reason to believe that the population of North Carolina is that different from the rest of the U.S.," Carey said. "We have an ethnically diverse population and an age spectrum similar to the rest of the country." Because most chronic diseases tend to occur at a slightly higher rate in the southeastern U.S., he said, "it is slightly possible that the percentage [of chronic lower back pain] might be somewhat higher in the southeast, but I think the most important issue is this increase over time."