P635. Incidence of inflammatory bowel disease in a private medical institution of Uruguay
G. Buenavida1, A. Silveira2, B. Iade1, 1School of Medicine, Gastroenterology, Montevideo, Uruguay, 2School of Medicine, Department of Quantitative Methods, Montevideo, Uruguay
According to previous data, Uruguay is among the regions of low incidence of Inflammatory Bowel Disease (IBD).
Objective: To determine the incidence of IBD in a private medical center in the greater metropolitan area of Uruguay in five years (2007–2011).
A prospective study was performed from January 1 st 2007 to December 31st 2011 in a private medical center (CASMU), with an average of 220,687 members, in the greater metropolitan area of Uruguay. To capture the case, multiple independent sources and active search in the records of the treating physician, general archive and pharmacy were consulted. The case was confirmed according to standard protocol after review by the principal investigators and a one-year follow up.
Statistical method: the average incidence rate and average rates specific for ulcerative colitis (UC) and Crohn's disease (CD) was calculated as the number of new cases per 100,000 members per year. We used the direct standardization method to adjust specific rates by age and sex, as defined by the standard WHO population.
55 new cases were diagnosed, 50 UC and 5 CD. The female/male ratio was 1.9. The mean age at diagnosis was 37.1±2.5 years old with a minimum and maximum of 7 and 87 respectively. There was no statistically significant difference in relation to age at diagnosis and sex, p-value = 0.178. The crude incidence rate 2007–2011 for IBD was 4.89/100,000 members/year, 4.44 for UC and 0.45 for CD. The adjusted incidence rate of IBD was 3.62/100,000 members/year, 3.42 for UC and 0.20 for CD. See the table.
The crude incidence rate by age group was 0.14 (for 5–14), 0.23 (for 15–19), 0.41 (for 20–44), 0.14 (for 45–64), 0.15 (for 65–74) and 0.07 (for >74 years old).
The location in the UC was proctitis in 14 patients, left-hand side in 16, and extensive in 20 of which 3 required surgery (colectomy) on debut.
The location on the CD was ileal in 2, colon in 3, there were no cases with perineal involvement and none required surgery during the study period.
This incidence rate of IBD places Uruguay in the regions of low incidence. As it has been described in low-incidence countries, UC is more common than CD. The peak incidence of IBD is between 20 and 44 years old followed by the group between 15 and 19 years old. This study establishes a precedent to follow the evolution of IBD epidemiology in Uruguay.