Introduction of electronic death notification in Norway-Impact on diabetes mortality registration

We studied changes in death statistics by deaths from diabetes mellitus (DM) after introduction of mandatory online death certificate (DC) submission in Norway. Information on deaths with DM mentioned in the DCs from year 2017 (DCs submitted on paper) to 2022 (DCs submitted online) was collected from the Norwegian Cause of Death Registry (NCoDR), Sex, age, year of death and type of DC (paper (pDC) vs electronic (eDC)) was registered. In DCs with DM as underlying cause of death (UCOD), all codes (International classification of diseases, 10th revision (ICD-10)), their original position in the DC and place of death were collected. DM was classified as type-1, type-2 and other. Differences between 2017 and 2022 according to use of unspecified DM diagnoses, number of changed diagnoses after automated processing, correct positioning of UCOD in DC, total number of diagnoses, and use of ill- defined diagnoses were analyzed. Generalized linear models for binomial outcome with log link were used to fit mortality data and test differences between electronic and paper registration systems, two-sample t-test and linear regressions for analysis of differences in number of diagnoses. 229 807 deaths were registered, including 3 864 DM deaths. Online DC submission increased from 0 in 2017 to 95% in 2022. In 2022, DCs with DM as UCOD showed significant less use of unspecified diabetes diagnoses (Relative risk,RR: 0.18, 95% confidence interval (CI): 0.14-0.22), reduced need for change of diagnoses after automated processing (RR: 0.52, CI: 0.46-0.59), reduced number of diagnoses (CI: -0.7 to -0.38), and less use of ill-defined diagnoses (RR: 0.83, CI: 0.71-0.97). The introduction of online cause of death submission in Norway improved the quality of registration of deaths from diabetes.