Is educational attainment associated with the onset and outcomes of low back pain? a systematic review and meta-analysis

Background: Low back pain (LBP) is the leading global cause of years lived with disability. Of the biopsychosocial domains of health, social determinants of LBP remain under-researched. Socioeconomic status (SES) may be associated with the onset of new LBP or outcomes of acute LBP, with educational attainment (EA) being a key component of SES. The association between EA and LBP has yet to be the subject of a dedicated review and meta-analysis. Purpose: To review evidence of the association between EA and a) onset or b) outcomes of acute and subacute LBP in the adult general population and to conduct statistical pooling of data where possible. Methods: An electronic search was conducted in MEDLINE, Embase, CINAHL, and ProQuest from inception to 2nd November 2023 including reference lists to identify relevant prospective studies. Risk of bias (RoB) was assessed using the Quality in Prognostic Studies (QUIPS) tool. Where adequate data were available, estimates were pooled using a random-effects meta-analysis. Overall evidence for each outcome was graded using an adapted GRADE. Results: After screening 8498 studies, 29 were included in the review. Study confounding and attrition were common biases. Data from 19 studies were statistically pooled to explore EA as a predictor of new LBP onset or as prognostic for outcomes of acute or subacute LBP. Pooled results showed no association between EA and the onset of new LBP (OR: 0.927, 95%CI: 0.747 to 1.150; I2 = 0%). For predicting outcomes of acute LBP, compared to those with no more than secondary-level education, post-secondary education or higher was associated with better outcomes of pain (OR: 0.538, 95%CI: 0.432 to 0.671; I2 = 35%) or disability (OR: 0.565, 95%CI: 0.420 to 0.759; I2 = 44%). High heterogeneity (I2>80%) prevented meaningful pooling of estimates for subacute LBP outcomes. Conclusion: We found no consistent evidence that lower EA increases the risk of LBP onset. Lower EA shows a consistent association with worse LBP outcomes measured at least 3 months later after acute onset with inconclusive findings in subacute LBP. Causation cannot be supported owing to study designs. High-quality research is needed on potential mechanisms to explain these effects.