Appendix B

A computer-based patient registration system was instituted at the Iiealth Department of Stockholm County Council in 1966. In 1971, an on-line system was installed at Beckomberga Hospital and since 1972, there has been a good precision in the registration. On extreme long-term patients, a baseline was set a t January I , 1960. Treatment episodes terminated prior to 1969 were not included, and there was a definite uncertainty up till 1972. The main register contained medical information on all terminated periods of inpatient care in the hospitals run by the Stockholm County Council. In this register, a great amount of information was stored. The main items were for each hospital stay, the actual hospital, department, date of admission, date of discharge and diagnoses. The medical information of the main register was combined with information on each individual from the census office. Here a long list of information was available including name, official identification number, age, sex. citizenship, marital status, pension, declaration of legal incompetence, year of census registration, actual address and parish of domicile. From the day of discharge, there was a delay of one to six months before the information had been processed. The main register was built for hospital administration reasons and from our point of view, it had a serious draw-back because only terminated hospital stays were included. It is worth mentioning, that the published annual medical statistics of 1976, presented the hospital stays terminated during that year. A number of inpatient days reported, may affect 1975 o r even earlier years (117). Since one of our aims was to reach the whole patient population, including non-discharged long-term patients and newly discharged patients, it was necessary to use a sub-system for actual inpatients. This register operated independently of the main register, and here, information was obtained concerning the actual hospital and department, day of admission. patient's name, identification number and parish of domicile. A sub-system of outpatient visits and daycare was put in operation on June 1,1980, at Beckomberga Hospital. A full description of the Stockholm County Medical Information System was available (45).