RESUMO
BACKGROUND: Assessment of chronic pain is frequently done in care centers. The aim of this study was to analyze the psychometric properties of the Chronic Pain Grade Scale (CPGS) - that measures both the intensity of chronic pain and its incapacitating effects on the everyday activities of the elderly. METHOD: Cross-sectional study of 185 people with chronic pain from two nursing homes. The questionnaire was adapted by back-translation and administered as a structured interview. It was assessed for reliability, internal consistency, construct validity, convergent and divergent validity (regarding the SF-12 score) and discriminant validity. Studied variables were compared among the pain groups derived from applying the scale. RESULTS: The scale showed sufficient reliability (a=0.90), bidimensionality (intensity and disability), good convergent and divergent validity and sufficient discriminant validity. Elderly people in groups I and II had better physical health than those in groups III and IV, but group II people had similar mental health to those from group IV (highest/limiting disability). Males, people with no education and pensioners were more frequently classified as group IV. CONCLUSION: The Spanish version of the CPGS has proved to be valid and reliable for evaluating both intensity and disability related to chronic pain in older people living in nursing homes.
