By using the explanatory analysis methods, we examined a possible model for the utilization of the Croatian Hospital Morbidity Register data for decision making in the managerial process for national health system development. To build a draft informational model, data were selected on 843 cases hospitalized in 1997 for diseases M30-M36 (ICD-10) in 45 health institutions. This was used as an index of the diagnostically/therapeutically most demanding group of rheumatic autoimmune diseases. Treatment standards were established for our health system for the patients having an M30-M36 disease by classifying Croatia's health institutions into four clusters by intensity of hospitalization, and by analyzing demographic characteristics and the length of stay by disease entity. These standards could represent a good informational base for forming consensus group panels to deal with inpatient treatment problems of patients with systemic connective tissue diseases.