Low Back Pain in Korea: Survey Weighted Analysis with Age Sex and Lumbar Radiographic Grade Matching

Background/Objectives: Low back pain (LBP) is a major public health problem that contributes substantially to disability and impaired quality of life. Methods: Using nationally representative data from the fifth Korea National Health and Nutrition Examination Survey (KNHANES V), this study evaluated the epidemiology of LBP among Korean adults aged 50–79 years and explored factors associated with LBP in relation to lumbar radiographic findings. Weighted analyses corresponding to an estimated 8,464,167 individuals were performed. Multivariable logistic regression was used to explore factors associated with LBP. In addition, to explore patterns of association under comparable demographic and radiographic conditions, we conducted analyses stratified by age, sex, and lumbar radiographic grade as a descriptive, exploratory approach. Results: In weighted estimates, 25.1% of participants reported LBP and 28.3% demonstrated radiographic lumbar spondylosis (Kellgren–Lawrence grade ≥ 2). LBP was consistently associated with depressive mood, osteoporosis, lower household income, and lifestyle-related factors, even under similar age and radiographic conditions. Conclusions: These findings suggest that LBP in Korea may reflect multidimensional health factors beyond lumbar radiographic severity alone.