Fig. 3

Random effects meta-analyses of prevalence estimates from included studies with standard emergency settings (n = 16). The pooled estimate (red line) is representative of the 16 studies included in each subgroup. Studies are grouped by the approach used to define the definition of low back pain: Meta-analysis 1 – Studies grouped by coding system used for the definition of low back pain, 1a “Complaint” indicates studies using presenting complaints for their definitions of low back pain, 1b “Diagnosis” indicates studies using diagnosis codes for their definition. Meta analysis 2- Studies are grouped by healthcare system funding, 2a “Private” indicates studies conducted in regions with private healthcare funding. 2b “Public” indicates studies conducted in regions with public healthcare funding. Meta analysis 3- Studies are grouped by definition of low back pain, 3a “Narrow” indicates studies using narrow definitions of low back pain. They used a definition of ‘low back pain’ or ‘non-specific low back pain’, or were limited to pain complaints in the lumbar region. 3b “Broad” indicates studies using broad definitions of low back pain. They used a general definition of ‘back pain’ to define their prevalence estimate, which may have included some individuals with back pain in regions other than the low back pain (for example, thoracic spine)