So, why the drastic increase? “We’re not sure,” Carey said. “That’s one of the things we’re studying next. But what appears to be happening is that today more people are transitioning from acute back pain to chronic back pain. So we asked ourselves: What’s different about our state and country now compared to 1992?”

For one, he said, people are a lot heavier. The percentage of North Carolinians who are obese has doubled. Other studies have linked back pain to increased weight, but Carey doesn’t think that’s the only reason.

Stress and depression could be contributing factors. About 50 percent of people in 2006 who had chronic low back pain also had symptoms of depression; of that group only 30 percent were on antidepressants. Many of those people were taking other medications, such as muscle relaxants, which can actually make you feel more depressed, he said.

Another issue could be the changing nature of the state’s workforce – a decline in the percentage of manufacturing jobs and an increase in construction and service industry jobs since 1992.

“Sedentary lifestyle gets offered up a lot as an explanation because we know that exercise is a good treatment for back pain,” Carey said, “but North Carolinians weren’t all that active in 1992 either.”

On top of this, Carey said, treatments have not been very effective. In fact, his latest study shows that patients are sometimes overusing treatments that don’t work and under-using those that are at least modestly effective, such as structured exercise programs.

In Carey’s study, less than 50 percent of the patients were prescribed exercise even though randomized trials have shown it to be a good treatment option.

In the medical literature that Carey has studied, there’s little to no evidence that many common treatments – including narcotics, steroid injections, traction, shoe inserts and back braces – help patients at all.

He also said that the increase in back pain prevalence has led to rising health costs and a drain on the economy.

“This is quite concerning because once you’re disabled from back pain, you may go on what’s called SSDI disability,” he said. “These patients don’t generally return to the workforce. They wind up on permanent disability until they turn 65. That’s a double whammy on society because these folks are obviously taking up tax dollars, but also they are suffering and not productive members of the economy. And once someone is on disability for a couple years, it’s very difficult for them to return to the workforce.”

Editor’s Note: The study on back pain prevalence, published in February in The Archives of Internal Medicine, was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases. The study on treatment effectiveness appeared in the journal Arthritis Care & Research.

University Gazette Vol. 34, No.8  May 13, 2009

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