Patient administrative system as a tool to validate the ascertainment in the diabetes incidence study in Sweden (DISS)

The aim of this study was to evaluate the degree of ascertainment in a nationwide prospective registration of incident cases of diabetes mellitus in the age group 15-34 years (The Diabetes Incidence Study in Sweden (DISS)). Incident cases of diabetes mellitus in DISS during a five year period were compared with inpatients, with the diagnosis of diabetes mellitus, registered in a routine computer-based administrative register. The Patient Administrative System-Inpatient Care (PAS-IC). To clarify this issue the two-sample capture-recapture phenomena was employed in the two southernmost counties in Sweden, Malmöhus and Kristianstad, covering 9.2% of the total of 2.3 million people aged 15-34 years in Sweden. The results showed that the ascertainment level in DISS was 0.86 for insulin dependent diabetes mellitus (IDDM). Hence, the DISS registry is a valid tool to monitor the incidence of IDDM in young (15-34 years) adult subjects.