To Örebro University

Introduction: Recent years have seen significant research advances within the gastroenterological field. Some of these consist of the recognition of serrated polyps as a precursor to colorectal cancer, and the realization of the health economic burden associated with gastrointestinal diseases.

Aim: In this thesis, we aim to validate the specificity of serrated polyps in the ESPRESSO cohort (Paper I). We also aim to estimate work loss in patients with celiac disease, including the temporal relationship of work loss before and after diagnosis (Paper II).

Method: By using the ESPRESSO cohort, we collected data on patients with serrated polyps and patients with celiac disease. In Paper I, the specificity of serrated polyps in the ESPRESSO cohort were validated by a structured retrospective review of patient chart. In Paper II, we estimated work loss in patients with celiac disease as compared withgeneral-population comparators matched on age, sex, county of residence and year of diagnosis.

Result: The presence of a serrated polyp was confirmed in 101 out of 106 individuals identified through the ESPRESSO cohort, yielding a positive predictive value of 95% (95% confidence interval: 89-98%). Patients with celiac disase had 42.5 lost work days as compared to 28.6 days in comparators (mean difference, 14.7; 95% confidence interval, 13.2-16.2), corresponding to a relative increase of 49%. Excess work loss in patients with celiac disease was observed even 5 years before diagnosis and remained eleveated during the years after diagnosis this loss. Notebly, the excess work loss was concentrated to a small proportion while most celiac patients did not have any work loss before or after diagnosis. 

Conclusion: The ESPRESSO cohort has a high specificity for serrated polyps. Patients with celiac disease miss more work days than the general population even before diagnosis, and this loss persists after diagnosis.