Table 4. OR_adjusted with 95% confidence intervals (95% CIs) of LBP symptoms based on multiple logistic regression (n = 344).

Demographic characteristic	Total	Prevalence(%) of LBP	ORadj	95% CI
The number of working days in a field for each group of age*
≤ 45 years old
≤ 5 days	93	93.5	1
> 5 days	80	77.5	0.2	0.1–0.6
> 45 years old
≤ 5 days	85	78.8	1
> 5 days	86	81.4	1.2	0.6–2.6
Level of stress*
Mild or moderate	191	78.5	1
High or severe	153	88.9	2.2	1.2–4.1

*Statistically significant (p-value <0.05)