Association between clinical, psychosocial and sociodemographic factors and ICF-domains in adults with chronic non-specific low back pain: a cross-sectional study.

BACKGROUND: Chronic non-specific low back pain (CNLBP) is the leading cause of years lived with disability worldwide. CNLBP is a multifactorial condition influenced by complex interactions between biopsychosocial components. This study aimed to investigate the association between clinical factors (e.g. disability, pain and prognosis), sociodemographic factors (e.g. age, gender, educational level, physical activity habits and medication use), and psychosocial factors (e.g. self-efficacy, quality of life, and fears and beliefs) in individuals with CNLBP, based on the International Classification of Functioning, Disability and Health (ICF). DESIGN: Cross-sectional study. METHODS: A total of 112 adults with CNLBP and aged 18–59 years were included. All participants were assessed using the following measures: disability (RMDQ); pain intensity; quality of life (EQ-5D-3 L); self-efficacy (LoBACS); fear-avoidance beliefs (FABQ); and risk of poor prognosis (STarT Back). The RMDQ items were linked to ICF domains to generate subscores: (1) body functions, (2) activity and participation. Three separate multiple linear regression models were then conducted to examine the association between a set of variables and the total score (disability) and the subscores: activity and participation, and body functions. RESULTS: Disability was primarily associated with higher fear-avoidance beliefs, older age, and greater pain intensity. In contrast, utility and low-risk prognostic classification showed significant negative associations with RMDQ scores. Together, these variables explained 58% of the variance. Activity and participation limitations were associated with age, low-risk classification, fear-avoidance beliefs and self-efficacy, explaining 56% of the variance. Body-function limitations were associated with pain intensity, utility, and fear-avoidance beliefs, explaining 28% of the variance. CONCLUSIONS: Distinct patterns of association were demonstrated between clinical, psychosocial and sociodemographic factors and ICF domains. Psychosocial factors played a central role in activity and participation, whereas pain intensity was more strongly associated with impairments in body function. These findings emphasise the importance of domain-specific biopsychosocial assessment strategies for individuals with CNLBP.