Validation of the Danish Colorectal Cancer Group (DCCG.dk) database - on behalf of the Danish Colorectal Cancer Group

The aim of this study was to validate the clinical quality database of the Danish Colorectal Cancer Group. The validation is meant to focus on core data regarding staging of the disease, treatment provided, patient-related factors and key complications.

This was a database validation study assessing the completeness of the database and the accuracy of the data by re-entering core variables into an online module in a blinded fashion and comparing re-entered data with the original database data. A sample of 5% of patients from the years 2014-2017 was randomly selected.

The sample of 936 patients was identified and data were re-entered. The completeness of the data retrieved was a median of 96%, 100% and 99% for preoperative, intra-operative and postoperative variables, respectively. The overall accuracy was a median of 95%. The least accurate variable was date of diagnosis (50% perfect agreement), with agreement rising to 96% when near matches defined as correct date ± 30 days were included. Intra-operative variables were of high quality, as were data on surgical complications including anastomotic leakage, where agreement was 97%.

This was the first major validation of the Danish Colorectal Cancer Group's database. Overall, the completeness and quality of data were high, but the validation process also identified weaknesses, which can be crucial for future users to acknowledge and consider.