In conclusion, it was found that the vast majority of workers analyzed present an ability to work fairly well. And consistent with the literature, it appears that the younger the better their individual work capacity. Similarly, this study shows that male workers and married workers have a better capacity for work compared to female workers and unmarried ones. It is an instrument of great importance to occupational health, in that it permits evaluation of the working capacity of the individual, the perception of the current state of work ability compared to his best, allowed the identification of areas of health injured and potentiate loss of working capacity and thus corrective measures, allows the evaluation of the effectiveness of these measures in overall capacity for work. Background and Aim: In chronic low back pain (CLBP) there is a high degree of comorbidity, and the prevalence of comorbid psychiatric disorders is between 40%-100%. The aim of this study was to assess the prevalence of psychiatric comorbidity in a population of CLBP patients, using a psychiatric diagnostic interview. Methods: 400 patients sick listed between 2 and 10 months for unspecific LBP were included in the study. All were recruited as part of an ongoing trial in secondary care, and were assessed with the Mini-International Neuropsychiatric Interview (MINI), which is a short structured diagnostic interview for DSM-IV and ICD-10 psychiatric disorders. Results: The prevalence of current psychiatric disorders was 30%. The diagnoses included a wide range of psychiatric disorders, with the most common being major depressive disorders (4%), substance abuse (4.3%), anxiety disorders (10%), and somatoform disorders (18%). There were no gender differences in prevalence of psychiatric disorders, and no differences in mean duration of back pain between those with and without a psychiatric disorder. Discussion: The results show that CLBP patients present with more psychiatric disorders than the general population, but less compared to previous studies of psychiatric comorbidity in CLBP. The difference could be a result of different compensational systems, different settings were the interviews were conducted, or different characteristics of the populations in the comparative studies. Conclusion: In a large population of CLBP patients, 30% fulfilled the criteria for at least one current psychiatric disorder when measured with a diagnostic interview. The results imply that screening LBP patients for psychopathology in secondary care is important and should involve a wide range of psychiatric disorders since psychopathology might have consequences for prognosis and treatment. Objective: To predict the two-year course of activity limitations in patients with early knee and/or hip osteoarthritis. Methods: The CHECK cohort comprising participants (N=1002) with early osteoarthritis-related knee and/or hip symptoms was followed for two years. Participants completed questionnaires, and underwent physical, laboratory and radiographic examination. Regression models were used to examine whether baseline variables predicted the course of activity limitations as measured with the WOMAC. Analyses were performed separately for participants with knee symptoms and participants with hip symptoms.