The functional barometer –a self-report questionnaire in accordance with the international classification of functioning, disability and health for pain related problems; validity and patient-observer comparisons

BACKGROUND: The International Classification of Functioning, Disability and Health, (ICF) provides a unified, international standardized framework for describing and classifying health and health-related functioning and disability. Based on an ICF core sets the Functional Barometer, (FB), was developed for assessments of perceived pain-related problems with functions, activity and quality-of-life by patients suffering from long-term pain. The aim was to evaluate the construct validity, and to compare the assessments of a patient’s problems from the perspectives of the patient and of the examining professional when using the validated FB and corresponding ICF-classification form, respectively. METHODS: Patients with long-term pain for more than 3 months that visited one of four pain clinics during specified time periods of data collections were eligible. The self-report Balanced Inventory for Spinal disorders was used for validation of the FB. Correspondingly to the validated FB an ICF-classification form for professional’s assessment was developed. The data sets for these inter-scale and the patient-professional comparisons were collected adjacent to the clinical examination. By the statistical method used for evaluation of the pairs of ordinal data presence of systematic disagreement was identified and measured separately from additional individual variations. RESULTS: The validation process resulted in a revised FB(2.0) that meets the requirements of good construct and content validity. The professionals’ ICF-classifications of the patients’ problems disagreed with the patients’ assessments on the FB(2.0); the percentage agreements ranged from 18% to 51%. The main reason was that the practitioners systematically underestimated the patients’ levels of problems but the different professionals contributed also to a large individual variability (noise) in assessment. CONCLUSIONS: This study presents an ICF-based validated self-report questionnaire, The FB, to be used for identifying and describing pain-related problems with current functioning, activities and quality-of-life as perceived by patients suffering from long-term pain. The strong evidences of underestimation of the patients’ problems and the variability in the professionals’ ICF-classifications demonstrated the importance of describing the patient’s problems both from the patient’s and the professional’s perspective beneficial for the patient’s rehabilitation.