Low back pain can be a long-term problem. Studies of low back pain need to be long-term, too. Repeated clinic visits over periods of several years can be inconvenient and expensive. These authors did a test using questionnaires like those used in clinic visits, but they sent them through the mail.
The authors sent out a questionnaire by mail to patients with long-term low back pain. They sent the same questionnaire a second time two weeks later. The questionnaires addressed back pain, work status, medications, and other factors. The authors also sent out some of the most widely used questionnaires for low back pain.
Almost 90 percent of the patients returned both questionnaires. The results showed that one particular type of questionnaire, called the Oswestry Disability Index (ODI), was reliable in the mail. Questions about work, back satisfaction, and pain medication also showed reliable results. The rest of the results were not so reliable. Rating pain seemed especially unreliable on the mail-in survey. This could be because pain varies quite a bit from day to day in patients with chronic low back pain. It could also be a problem with the survey.
This preliminary study shows that questionnaires by mail may be effective in helping researchers do follow-up studies with low back pain patients. More research is needed, especially in understanding the way questionnaires by mail reflect real pain levels.