Background: The increasing prevalence of disability pensioning in Norway has led to several attempts at strengthening the proactive role of the National Insurance System (NIS) in cases of long-term sick-listing. Since 1988, a special medical certificate is required after eight weeks of sick-leave. The aim of this study was to examine whether systematic evaluation of this medical certificate by NIS officers and NIS medical consultants could reduce future health insurance expenditure.
Material and methods: In 1994 a randomised study using a paired design of the NIS local offices in the county of Hordaland was undertaken. All eight-week medical certificates in the intervention group (N = 2,237) were systematically reviewed, whereas standard routines were used for the control group (N = 1,764).
Results: After three years, no significant differences were observed between the two groups in health insurance utilisation.
Interpretation: We conclude that local NIS offices are unable to use the information in the eight-week sick notes to effectively influence future utilisation of health insurance. The reason may be that NIS offices lack the skills necessary for early intervention in long-term sick-listing.