Risk factors for low back pain and sciatica: an umbrella review

Background: Low back pain (LBP) is a highly prevalent condition and it is associated with significant disability and work absenteeism worldwide. A variety of environmental and individual characteristics have been reported to increase the risk of LBP. To our knowledge, there has been no previous attempt to summarize the evidence from existing systematic reviews of risk factors for LBP or sciatica. Purpose: To provide an overview of risk factors for LBP, we completed an umbrella review of the evidence from existing systematic reviews. Study Design: An umbrella review was carried out. Methods: A systematic literature search was conducted in MEDLINE, EMBASE, PubMed PsychINFO, and CINAHL databases. To focus on the most recent evidence, we only included systematic reviews published in the last 5 years (2011–2016) examining any risk factor for LBP or sciatica. Only systematic reviews of cohort studies enrolling participants without LBP and sciatica at baseline were included. The methodological quality of the reviews was assessed independently by two review authors, using the Assessment of Multiple Systematic Reviews tool. Results: We included 15 systematic reviews containing 134 cohort studies. Four systematic reviews were of high methodological quality and 11 were of moderate quality. Of the 54 risk factors investigated, 38 risk factors were significantly associated with increased risk of LBP or sciatica in at least one systematic review and the odds ratios ranged from 1.26 to 13.00. Adverse risk factors included characteristics of the individual (eg, older age), poor general health (eg, smoking), physical stress on spine (eg, vibration), and psychological stress (eg, depression). Conclusion: Poor general health, physical and psychological stress, and characteristics of the person increase risk for a future episode of LBP or sciatica.