Registration in the Danish Regional Nonmelanoma Skin Cancer Dermatology Database: completeness of registration and accuracy of key variables

OBJECTIVE: To validate a clinical database for nonmelanoma skin cancer (NMSC) with the aim of monitoring and predicting the prognosis of NMSC treated by dermatologists in clinics in the central and north Denmark regions. METHODS: We assessed the completeness of registration of patients and follow-up visits, and positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity of registrations in the database. We used the Danish Pathology Registry (DPR) (n = 288) and a review of randomly selected medical records (n = 67) from two clinics as gold standards. RESULTS: The completeness of registration of patients was 62% and 76% with DPR and medical record review as gold standards, respectively. The completeness of registration of 1st and 2nd follow up visits was 85% and 69%, respectively. The PPV and NPV ranged from 85% to 99%, and the sensitivity and specificity from 67% to 100%. CONCLUSION: Overall, the accuracy of variables registered in the NMSC database was satisfactory but completeness of patient registration and follow-up visits were modest. The NMSC database is a potentially valuable tool for monitoring and facilitating improvement of NMSC treatment in dermatology clinics. However, there is still room for improvement of registration of both patients and their follow-up visits.