Association of Back Pain with Mortality: a Systematic Review and Meta-analysis of Cohort Studies

Background: Back pain is the most common cause of disability worldwide. While disability generally is associated with greater mortality, the association between back pain and mortality is unclear. Our objective was to examine whether back pain is associated with increased mortality risk and whether this association varies by age, sex, and back pain severity. Methods: A systematic search of published literature was conducted using PubMed, Web of Science, and Embase databases from inception through March 2019. We included English-language prospective cohort studies evaluating the association of back pain with all-cause mortality with follow-up periods >5 years. Three reviewers independently screened studies, abstracted data, and appraised risk of bias using the Quality in Prognosis Studies (QUIPS) tool. A random-effects meta-analysis estimated combined odds ratios (OR) and 95% confidence intervals (CI), using the most adjusted model from each study. Potential effect modification by a priori hypothesized factors (age, sex, and back pain severity) was evaluated with meta-regression and stratified estimates. Results: We identified eleven studies with 81,337 participants. Follow-up periods ranged from 5 to 23 years. The presence of any back pain, compared to none, was not associated with an increase in mortality (OR, 1.06; 95% CI, 0.97 to 1.16). However, back pain was associated with mortality in studies of women (OR, 1.22; 95% CI, 1.02 to 1.46) and among adults with more severe back pain (OR, 1.26; 95% CI, 1.14 to 1.40). Conclusion: Back pain was associated with a modest increase in all-cause mortality among women and those with more severe back pain.