Short summary

Within this study we aim to investigate the long term health consequences of occult blood in the stool. Specifically, our objectives are to:

• Calculate the level of morbidity within a population with a negative stool test
• Calculate the level of morbidity within a population with a positive stool test and subsequent negative colonoscopy
• Present the mortality rates and survival curves of people with negative stool tests and people with positive stool tests and subsequent negative colonoscopy

Rationale

The Kronborg data consists of a database established with an initial randomised controlled study conducted in Funen in 1985. Subsequently, the cohort of patients was followed for a number of years, and data are currently stored in the Danish National Archives (tDNA). Thus they can be obtained on request and permission from Kronborg, who initiated the studies.

In 1976 a comprehensive registration of health services utilisation, morbidity, and mortality on an individual level was implemented in Denmark, the National Patient Registry (NPR). Thus, the registry data combined with the original blood stool data from Kronborg enables a thorough investigation into the long term predictive value of iFOBT.

Description of the cohort

Data will be obtained from tDNA including the personal identification number (ID) for each individual alongside result of the stool blood test and results of subsequent colonoscopy in terms of polyps/cancers identified and other diseases detected. The ID-numbers will be used for a request for data in NPR including all subsequent diagnostic and treatment procedures that each individual has received until end of follow-up or death.

Data and biological material

Data will be requested from the Danish National Archives and the National Patient Registry.

Collaborating researchers and departments

Department of Surgery, Odense University Hospital, Svendborg Hospital

• PhD-student Issam Al-Najami
• PhD-student Anne-Kirstine Dyrvig