Sensitivity of colonoscopy registration in the Swedish Patient Register compared to SCREESCO

BACKGROUND: Accurate registration of colonoscopies in registers is essential for register-based research of colonoscopy use and outcomes. We aimed to assess the sensitivity of colonoscopy registration in the Swedish National Patient Register (NPR) compared to colonoscopy data from the SCREEning of Swedish COlons (SCREESCO) study. MATERIAL AND METHODS: All individuals who underwent a colonoscopy through SCREESCO were included in the current analysis at the date of their first SCREESCO colonoscopy. Colonoscopies registered in the NPR on the same date as the SCREESCO were identified and we estimated the sensitivity of finding a SCREESCO colonoscopy in the NPR overall and according to calendar year, profession (gastroenterologists, surgeons, and endoscopy nurses) and health care regions, with 95% confidence intervals (CIs). RESULTS: The overall sensitivity was 64% (95% CI: 63-65%, n = 10,638/N = 16,555), more than twice as high among gastroenterologists (76%, 95% CI: 76-77%, n = 7240/N = 9473) and surgeons (87%, 95% CI: 86-89%, n = 1739/N = 1990) than among nurse endoscopists (32%, 95% CI: 30-33%, n = 1619/N = 5092), and varied across regions and calendar time. CONCLUSION: The trend of increasing number of colonoscopies performed by nurse endoscopists may cause major underreporting in the NPR.