RESUMEN
BACKGROUND: Low back pain is a leading cause of disability in Brazil. The multiple aspects of disability in these patients require comprehensive tools for their assessment. The International Classification of Functioning, Disability, and Health (ICF) core set for low back pain is designed to comprehensively describe the experience of such patients with their functioning. AIM: This study aimed to describe functioning and contextual factors and to empirically validate the ICF core set for low back pain. DESIGN: Cross sectional study. SETTING: Three outpatient clinics in Manaus, Maceio and São Paulo, Brazil. Population. 135 low back pain outpatients under rehabilitation. METHODS: Data concerning diagnosis, personal features, and the 78 ICF core set categories for low back pain were collected from clinical charts, physical examinations, tests, and interviews with patients from rehabilitation services in three parts of Brazil. RESULTS: 7.7% of the categories (6 body functions and 10 activity and participation) were affected in less than 20% of the sample, and were thus considered not validated. Pain and other sensations related to the musculoskeletal system were the body most frequently impaired functions. Mobility and domestic life were the chapters of activity and limitation most often described as limited. All environmental factors were qualified as either facilitators or barriers and acted as modulators of disability. CONCLUSION: The comprehensive ICF core sets for low back pain can be used to describe the living experience of such individuals, although efforts to make it operational and enhance the reproducibility of the results are needed to warrant its reliable routine use. CLINICAL REHABILITATION IMPACT: This study highlights the importance of a complete assessment of chronic low back pain and demonstrate the need for multidisciplinary approach.