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

Abstract 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, Malmohus 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.