The association between the weight of schoolbags and low back pain among schoolchildren: A systematic review, meta-analysis and individual patient data meta-analysis

Abstract

Background: The objective of this study was to determine whether carrying a heavy schoolbag is associated to a higher prevalence of low back pain (LBP). Methods: A systematic review and meta-analysis was conducted (PROSPERO, CRD42018077839). Observational studies analysing the relationship between schoolbag weight and LBP, were searched for in 20 electronic databases and 12 specialized journals until February 28th, 2019, without date or language restrictions. All studies which included ≥ 50 subjects aged 9 to 16, were reviewed. Methodological quality was assessed by two reviewers separately, using validated tools. A meta-analysis and an individual patient data (IPD) meta-analysis were conducted to examine the relationship between schoolbag weight and LBP. Certainty of evidence was assessed using an adapted GRADE methodology. Results: 5,524 citations were screened, 21 studies (18,296 subjects) were reviewed and 11 studies (9,188 subjects) were included in the meta-analysis. The IPD meta-analysis included 9,188 subjects from seven studies. Among the 21 studies reviewed, the mean score for methodological quality was 78.3 of 100. Only one study suggested an association between heavier schoolbags and LBP. Neither the meta-analysis nor the IPD meta-analysis found an association between carrying schoolbags weighing > 10% of bodyweight, and LBP. No differences based on age, gender or sport activity were found. Discussion: Available evidence does not support that schoolbags weighing > 10% of bodyweight are associated with a higher prevalence of LBP among schoolchildren aged 9-16. The certainty of evidence is low. Further research is required on the relationship between schoolbag weight and LBP. Significance: This systematic review, with a meta-analysis and an IPD meta-analysis, failed to find a link between schoolbags weighing ≥ 10% of body weight and LBP among schoolchildren aged 9 to 16. Further longitudinal studies, with large samples, long follow-up periods, and rigorous methods taking into account duration of carry and the physical capacity of each subject, are required in this field.