BackgroundLow back pain (LBP) is a common health problem in workers that contributes to work disability and reduces quality of life. However, studies examining vulnerable groups in relation to sociodemographic differences in LBP remain scarce. Therefore, the current study investigates which sociodemographic groups of workers are most affected by LBP.MethodsData from the 2018 BIBB/BAuA employment survey were used (N = 16252). Age, education, occupational group, income, working hours, atypical working time, relationship status, and having children were used as sociodemographic predictors. Gender-stratified logistic regression analyses and intersectional classification tree analyses were conducted.ResultsA higher prevalence of LBP was observed for women compared to men. Significant differences in LBP emerged for age, working hours, atypical working time, occupational group and education, with some gender differences in the importance of predictors: Age was a significant predictor mostly in men as compared to women, atypical working hours had a slightly greater effect in women, whereas differences in LBP according to the occupational group were more pronounced for men. Vulnerable groups were found to be women who work in occupations other than professionals or managers, work atypical hours and have an intermediate or low educational level as well as men who work as skilled agricultural workers, craft workers, machine operators, or elementary occupations and are between 35 and 64 years old.ConclusionsThus, workers with certain occupations and lower levels of education, middle-aged men and women with unfavourable working time characteristics are most affected by low back pain. These groups should be focused on to potentially increase healthy working life and prevent work disability.