I've been reading up on back pain. I see lots of studies from around the world on this topic. Scientists in Sweden seem to really follow their back pain patients the longest. Doesn't getting older increase the risk of back pain? How do they account for this factor?

You ask a question that the scientists look at too. In an ongoing series of studies from the University of Linköping in Sweden, patients are surveyed every five years. Questions are asked about pain, function, and general health. The patients are also asked how often they see a health care provider for their back pain.

They recognize that one factor affecting results could be age. General health may decline with age. The scores for general health will reflect the increasing age. It's not clear if changes in pain and function can also be linked to age. The answer to this question may come as more studies are done with more people in each study.