The Stockholm Diabetes Intervention Study (SDIS) aimed to determine whether intensified insulin treatment were feasible and led to less serious diabetic complications. 102 patients with type 1 diabetes mellitus were randomized (October 1982 to March 1984) to intensified conventional treatment (ICT; n=48) or standard treatment (ST; n=54). The randomized SDIS study lasted for 7.5 years, whereas 96 patients were fully evaluated. Thereafter patients were assigned to their regular clinical visits.