[Etiology and prevalence of chronic pain in adults: a narrative review].

The chronic nonmalignant pain is an underestimated epidemiologic health problem. It is a disease in its own right. It is one of the major reasons because patients use health service. The magnitude of chronic pain is in terms of human suffering and costs to society. The aim of this review is to identify the diagnosis and the prevalence of nonmalignant chronic pain in the adults. We have done a review of the literature from 1998 to 2012 using the virtual newspaper libraries starting from data bases (Pub-Med, CINAHL, Cochrane). We have made a narrative review of the articles obtained. Excluding topics of headache, pain for pediatric and geriatric groups, cancer pain and disease-specific items. Studies were classified for year, author sample, methods, age groups and definition of pain. We have obtained 7 articles. These epidemiological studies conducted in different part of the world, reported prevalence rates of chronic pain ranging from 16-53%. They shows a high heterogeneity of results concerning diagnosis and methods. Although limited the number of articles, show the high complexity of the phenomenon.