Prevalence of low Back pain among adolescents in relation to the weight of school bags

Table 5 Association between the perceived heaviness of school bags and low back pain before and after adjusting for potential confounders

Perceived heaviness of school bag*	Model 1 OR [95%CI]	Model 2 OR [95%CI]	Model 3 OR [95%CI]	Model 4 OR [95%CI]
Light	1.00 [Reference]	1.00 [Reference]	1.00 [Reference]	1.00 [Reference]
Normal	1.23 [0.70–2.18]	1.19 [0.67–2.12]	1.19 [0.66–2.12]	1.20 [0.67–2.15]
Heavy	1.98 [1.13–3.50]	1.71 [0.95–3.04]	1.68 [0.94–3.00]	1.65 [0.92–2.96]
Very heavy	4.20 [2.19–8.06]	3.59 [1.85–6.98]	3.54 [1.82–6.91]	3.41 [1.74–6.68]
p-value	< 0.001	< 0.001	< 0.001	< 0.001

*78 students are excluded from the analysis because they have no school bag. OR: odds ratio; Model 1: unadjusted; Model 2: adjusted for socio-demographic factors (gender, governorate, education of the father); Model 3: adjusted for variables in the Model 2 in addition to the weight of the bag, number of days the students carry their bag to schools and number of bags taken to schools; Model 4: adjusted for variables in Model 3 in addition to smoking and hours per day spent on watching TV/using computer

ISSN: 1471-2474