[Who is long-term sick-listed in Norway? From the project Evaluation of the follow-up of long-term sick-listed].
The aim of the study was to analyse the characteristics of persons with long-term sickness certification at the end of 1990 in Norway. The study was based on data registered by the National Insurance Administration: Age, sex, place of residence, diagnoses, and prognosis as registered on Sickness certificate II. At the end of 1990 a total of 57,567 persons had been incapacitated for work for longer than eight weeks and up to 52 weeks. The prevalence was 27.9 per 1,000 employed persons, with a significantly higher prevalence among women than among men. 25% of the women certified as sick were 40-49 years old. The highest prevalence of long-term certification of sickness was found in the counties Finnmark and Troms in Northern Norway, and Hedmark in central Norway. In cases of long-term sickness certification, the most common diagnoses were musculoskeletal/connective tissue diseases and mental disorders, with a prevalence of 9.3 and 3.1 per 1,000 employed persons respectively. The study indicates the possibility of using data from existing administrative population registers to provide information on the epidemiology of long-term sickness certification in Norway. It is necessary to further improve the validity of the data.