Low back pain and the social determinants of health: a systematic review and narrative synthesis

The social determinants of health (SDH) are known to differentially impact outcomes from many noncommunicable diseases; however, their potential role in low back pain (LBP) is poorly defined. This review endeavours to comprehensively inform the field of their relevance. Our research question was: "How do the broad range of SDH and chronic LBP (CLBP) relate?" The primary aim of this review was to synthesise evidence of relationships between SDH and the frequency or severity of CLBP. Secondary aims were to identify relationships between SDH and LBP-related disability, work absenteeism, and opioid prescription. We included studies involving adult participants that evaluated relationships between one or more of the SDH and CLBP frequency or LBP outcomes (beyond 3 months). Two reviewers screened studies, extracted data, and assessed risk of bias. We synthesized the results narratively and applied PROGRESS to organise our findings. Database searches identified 7018 records. Forty-one studies were included, containing data from 2,161,617 adults from 17 countries. Twenty-four percent and 19% of the relationships included were classified as having a high risk of bias due to confounding and missing data, respectively. We reported 166 relationships representing the majority of the PROGRESS domains. An array of independent and interdependent relationships between the SDH and CLBP were identified with the strongest evidence for associations related to educational attainment and socioeconomic status. Our findings suggest that greater recognition of the contribution of SDH to disparities in LBP outcomes is warranted and this has the potential to usefully inform strategies to impact burden.