TUESDAY, March 25, 2014 (HealthDay News) -- Low back pain causes more disability than nearly 300 other conditions worldwide, according to new research, and nearly one in 10 people across the globe suffers from an aching lower back.
A second study, which looked at the condition in specific types of jobs, found that low back pain is responsible for about a third of work-related disability.
"Low back pain is something that almost all people experience at some point in their lives. It is something common across sexes, age groups, countries, socioeconomic groups, education levels and occupation," said the lead author of the first study, Damian Hoy, a senior research fellow at the University of Queensland's School of Population Health, in Australia.
"For the majority of people with low back pain, the specific cause is unclear," he said, but "there are certain factors that seem to put people at risk of having low back pain."
Older age, low education, obesity, having stress, anxiety or depression -- as well as occupations that require significant heavy lifting or are extremely stressful -- are all factors that increase the risk of low back pain, according to Hoy.
One U.S. expert said the results didn't surprise him.
"Back pain is the number one cause of lost work days in the U.S," said Dr. Anders Cohen, chief of neurosurgery and spine surgery at the Brooklyn Hospital Center, in New York City.
For the first study, Hoy and his colleagues reviewed 117 published studies that included information on low back pain prevalence. They also reviewed surveys done in 50 countries on back pain prevalence and severity.
Compared to 291 other health conditions, the researchers found that low back pain causes more global disability than any other health problem studied. Back pain affected 9.4 percent of people in 2010, their analysis showed.
Men were more likely than women to have back pain -- an average of just over 10 percent of men had back pain compared with 8.7 percent of women.
Back pain also varied significantly by geographic area. "Prevalence was highest in Western Europe followed by North Africa/Middle East, and lowest in the Caribbean followed by Central Latin America," Hoy said.
In Western Europe, the average prevalence of back pain was 15 percent, and in the North Africa/Middle East region, it was 14.8 percent. The lowest rates were found in the Caribbean, where the prevalence rate was 6.5 percent, and in Central Latin America, where it was 6.6 percent, Hoy reported. Low back pain prevalence was 7.7 percent in high-income areas of North America.
Higher levels of exercise, shorter height, higher pain thresholds, and less access to health insurance may be reasons why developing countries reported slightly lower rates of low back pain, Hoy suggested.
The second study -- done by researchers in Australia and the United States -- looked at data from 187 countries from 1990 and 2010. Just over one-third of all work-related disability was related to low back pain, the study found.
The risk of low back pain was nearly four times higher for people working in agriculture, animal husbandry, forestry, fishing and hunting compared to other professions, reported a team led by Dr. Tim Driscoll of the University of Sydney, in Australia.
People working in production, laborers and transport equipment operators had a 54 percent higher risk of low back pain, while service workers had a 47 percent increased risk, according to the study. Clerical work was associated with the lowest rates of low back pain.
Staying in shape is one of the best ways to prevent back pain, according to U.S. expert Cohen. "The average young adult may be athletic and in pretty good shape," he said. "Once you get into your job life, you may not keep up your normal fitness level and combine that with aging and then exercising a lot on the weekends, and you end up with a situation that's not good for your back," he explained.
He said it's important to maintain core strength and flexibility to keep your back healthy.
For people who already have low back pain, Dr. Rachelle Buchbinder, a co-author on Hoy's study and a professor of epidemiology and preventive medicine at Monash University in Australia, had suggestions for their doctors.
"For nonspecific low back pain -- which explains the majority of back pain -- evidence-based management involves reassurance about the favorable prognosis, advice to continue usual activities and stay active, and the prescribing of simple analgesics [painkillers] as needed," Buchbinder said
Both she and Cohen said surgery isn't often necessary.
"With aging and growing populations, low back pain is an enormous burden in developing countries," lead author Hoy said. "This is predicted to grow substantially over coming decades and will likely have an enormous impact on individual livelihoods, health care systems and economies."
Both studies were published online on March 24 in the Annals of the Rheumatic Diseases.
Learn more about back pain from the U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases.