Study Looks at Low Back Pain in Working-Age Adults

A Swedish study in the October 1 issue of the journal Spine provides new insights into the rate and outcomes--including missed work time--of low back pain in the working-age population.

The findings re-emphasize "how extensive and commonplace the low back problem is, showing that it is more than rule than the exception for human beings, regardless of age, gender, or occupation," conclude the authors, led by Dr. Eva Vingard of the Swedish National Institute for Working Life.

Dr. Vingard and her fellow researchers assessed back pain in a population of 17,000 Swedish men and women, aged 20 to 59. Over a three-year period, five percent of these working-age adults sought treatment for back pain. About half were treated by a physician or physical therapist and the rest by chiropractors or other "alternative" providers.

The patients were followed up for two years to find out how their episode of back pain resolved. At first, pain and disability scores improved. On a scale of 0 to 100, the median pain score decreased from 43 to 30 during the first three months, while median disability score decreased from 23 to 10.

After three months, however, there was little further improvement. At six months' and two years' follow-up, the median pain score remained around 30 and median disability score around 10.

Despite their continued pain, most patients missed little or no work time. About 70 percent did not take a single day of sick leave because of back pain.

About 60 percent of patients made repeated visits to their doctor or other health care provider for back pain treatment. However, these patients actually showed less improvement than those who did not receive treatment during follow-up. The study did not gather information on exactly what treatments the patients received.

Most patients said their back pain was better after two years' follow-up. However, about one-fourth felt there was no change while fifteen percent said their pain had gotten worse.

The results underscore the high frequency of low back pain in working-age adults. For most patients, back pain improves after they seek professional care. However, most of the improvement occurs within the first few months and the problem usually does not go away completely.

Because low back pain is so common, missed work time due to back pain remains an enormously expensive problem. Most affected workers take no sick leave because of back pain, despite experiencing continued pain and disability. "The study strengthens the hypothesis that low back pain becomes chronic even when sick leave is rare," Dr. Vingard and coauthors conclude.