BACKGROUND & OBJECTIVE
Several studies have noted an association between poor sleep quality or quantity, and back pain. However, the nature of the relationship is uncertain; either could be the cause og the other, or something else could be responsible for both. There are palusible theories for all these relationships. This study aimed to investigate if sleep quality is a prognostic factor for back pain. That is to say, whether people with back pain who are sleeping poorly are at risk of longer duration of back pain and disability than those who sleep better.
The researchers recruited consecutive patients presenting to 25 centres in Spain for subacute (>2 weeks) or chronic (>3 months) nonspecific low back pain (LBP). Centres included primary care, and specialist services. Study assessment involved self-reported questionnaires at initial consultation (baseline) and 3-month follow-up. Critical measures were the Pittsburgh Sleep Quality Index, two visual analogue scales (current LBP, and current leg pain), and the Roland Morris Disability Questionnaire. Potential confounders included a range of demographic and clinical measures. The study used a series of logistic regression models to assess the relationship between sleep and improvement in LBP and disability.
Study participants (n=461 at baseline) had a median back pain intensity pf 4 out 10, a median Roland Morris score of 4 out 24, and 57% had poor sleep quality. Baseline scores indicate a sample with mild pain and disability,