AG

AA

bst

ract

sS1155

A Population-Based Ecological Study Identifies Population Density, Urban/Rural Location, and Spatial Clustering As Determinants of Susceptibility toEarly-Onset Inflammatory Bowel Disease in ScotlandDavid C. Wilson, Kevin G. Pollock, Johan Van Limbergen, Emma L. Armitage, Marian C.Aldhous, Hazel E. Drummond, Helen E. Ternent, Giles T. Innocent, Jack Satsangi

Background and Aims - The recent increase in incidence of early-onset inflammatory boweldisease (EO IBD) and geographical variability suggest either environmental factors or gene-environmental interactions contribute to aetiology. By use of an ecological study, we aimto describe spatial and temporal epidemiology of EO IBD in Scotland, looking at populationlevel variations in EO IBD and in socio-demographic and environmental associations withthese variations. Methods - The Scottish Hospital Discharges Linked Database followed bycase note verification was used to identify all children aged less then 16 years for thediagnosis of Crohn's disease (CD) or ulcerative colitis (UC) between January 1986 andDecember 1995, with diagnosis of IBD by Lennard-Jones criteria (Scand J Gastro1989;170(suppl): 2-6). Postcode sectors were used to study human population data basedon the 2001 census and livestock data from the 2000 agricultural census. A binomial modelwas fitted to data using a generalised linear model (GLM) with case diagnosis as CD or UC.Cases of UC and CD were modelled independently using a Poisson GLM, dependent variablecases per postcode sector and independent variables human population density, cattle popula-tion density, sheep population density, deer population density, goat population density,pig population density, ratio of farms per person and 2 orthogonal axes (west-east, south-north). Spatial scan statistic and space-time scan statistic were used to identify possibleclusters in space and time. Results - 417 patients (266 (64%) CD, 151 UC) with EO IBDwere included, with age ranging from 9 years to 15 years and 11 months at diagnosis. 219(53%) were male. On the binomial model, males were significantly more likely to developCD (OR 1.54, P<0.05). Human density was significantly protective for both CD (P <0.001)and UC (P<0.05). Farms per person (an index of rurality) was significant for CD (p<0.001)but not UC (p 0.07). Cases of UC were found more in the west than the east (P=0.07). Onspatial clustering, the north-west of Scotland had higher number of UC cases (p<0.001); therewere no temporal clusters and no significant space-time clusters. Summary and conclusions -Higher human density is protective at the time of diagnosis of IBD. CD but not UC is morelikely to develop in those living in the most rural of locations. Children and teenagers inthe west of Scotland were more likely to develop UC than in the east of Scotland. We haveconfirmed the male predominance of EO CD. This ecological study did not show anysignificant effect of animal population density.

S1156

Fatigue and Health Related Quality of Life (HRQOL) in PediatricInflammatory Bowel Disease (IBD)Seth B. Marcus, Jennifer A. Strople, Katie Neighbors, Jill Weissberg-Benchell, James W.Varni, Estella M. Alonso

Fatigue is an integral component of one's quality of life and a common complaint amongpatients with IBD. This study examined the prevalence of fatigue and the level of HRQOLof children with IBD from the child's and parents' perspective. METHODS: Patients 10 to17 years of age with established IBD cared for at a university center were eligible. Patientsand parents completed an age-appropriate version of the Pediatric Quality of Life Inventory™(PedsQL™), the PedsQL™ Multidimensional Fatigue Scale, the IMPACT-III Quality of LifeQuestionnaire and the Children's Depression Inventory: Short Version. Disease activity wasdetermined according to the diagnosis using either the Pediatric Crohn's Disease ActivityIndex (PCDAI) or a Physician's Global Assessment (PGA). Results were compared to a sampleof age, gender, and SES matched healthy controls. Higher scores indicate less fatigue andhigher HRQOL. RESULTS: 70 children with IBD were compared with 157 controls. Patientswere 55% male, 69% Caucasian, and had a mean age of 14.1 ± 2.1 years. Those withCrohn's disease (N=52) had a median PCDAI of 0 (interquartile range, 0-7.5) and 56% withulcerative colitis (N=13) or indeterminate colitis (N=5) were in remission. Mean totalIMPACT-III score was 137.7 ± 20.9. There were no significant differences in ethnicity,depressive symptoms, or BMI between patients with IBD and controls. Mean PedsQL™Multidimensional Fatigue scores were 73.9 ± 16.8 and 82.2 ± 12.3 for patients with IBDand controls, respectively (p=0.0003). Mean PedsQL™ scores were 76.7 ± 14.2 and 85.9± 10.4 for patients with IBD and controls, respectively (p<0.0001). CONCLUSION: Childrenwith IBD report more fatigue and lower HRQOL than healthy controls. Effect sizes aremoderate to large suggesting differences are clinically relevant and may be targeted for inter-vention.PedsQL™ Multidimensional Fatigue Scale

a p<0.0001, b p<0.001, c p<0.01. Effect Size=Small(0.20),Medium(0.50),Large(>0.80)

T : 11501$$CH204-02-08 16:47:06 Page 190Layout: 11501B : e

A-190AGA Abstracts

S1157

CT Colonography in Patients with Incomplete Conventional Colonoscopy:Evaluation of a Colon Dissection Mode (Filet View) for Virtual ColonoscopyJuergen M. Gschossmann, Hanno Hoppe, Peter Vock, Bettina Saar

Background: During the last decade, virtual colonoscopy has turned into a potentiallyreliable alternative to established techniques for colon cancer screening. Multiple automatedpostprocessing tools have been developed to facilitate the time consuming analysis and toincrease the diagnostic accuracy. However, an incomplete colonoscopy due to often reducedcolon preparation with remaining stool and fluid artefacts continues to represent a majorchallenge. Aim: To evaluate A) a colon dissection mode (filet view) and B) an integratedcomputed assisted reading mode in patients with incomplete colonoscopy. Methods: Intotal, 30 patients (45-88 years, median age 63 years, 18 males, 12 females) with CTcolonoscopy (CTC) were included. Fifteen patients had undergone an incomplete colonos-copy beforehand and findings of CTC were correlated with the surgical results or a follow-up colonoscopy (test group). A second group of 15 patients underwent CTC first, followedby complete conventional colonoscopy on the same day (control group). CTC was performedin prone and supine position using multislice computed tomography (Sensation 16, Siemens;Asteion; Toshiba). Postprocessing was performed using a specific CT postprocessing workst-ation (Extended BrillianceTM Workspace, Philips) equipped with 3D-colon dissection mode(filet view) as well as a computed assisted reading system. Results: In the test group, 5carcinoma and 16 polyps >5 mm were found. In the control group, only 2 polyps >5 mmwere detected. Sensitivity and specificity using the filet view was 75% (sensitivity) and 100%(specificity) in mean analyzing time of 14.2 min for the test group. In the test group, onecarcinoma was missed in the filet view. For the control group, sensitivity/specificity were83% and 100% in mean analyzing time of 10.5 min. Using multiplanar reconstruction alonein the test group, sensitivity increased to 87% (100% looking only for carcinomas) andspecificity of 100%. However, analyzing time increased to 17.5 min using only multiplanarreconstruction in the test group. In the control group, sensitivity/specificity using multiplanarreconstruction reached 33% and 100% in mean analyzing time of 16 min. Computed assistedreading showed sensitivity/specificity of 57% and 62% in the test group versus 80% and54% in the control group. Conclusion: The completely automated 3D-reconstruction mode“Filet view” is time efficient and shows a high efficacy in a well prepared colon. However, inpatients with incomplete colonoscopy and poor colon preparation, additional time consuminganalyzing modes are needed. Computed assisted reading can be of additional help forscreening purposes.

S1158

Clostridium difficile Colitis in An Inpatient Population: Value of CT inEstablishing PrognosisAnil R. Balani, Gene Young Im, Paul Panzarella, Cheng Ting Lin, Rani J. Modayil, SimchaPollack, Douglas S. Katz, James H. Grendell

Background:Clostridium difficile-associated disease (CDAD) ranges from diarrhea to life-threatening pseudomembranous colitis, mostly associated with previous antibiotic exposure.Recent studies have shown the increasing incidence of CDAD and emergence of more virulentC. difficile strains leading to a healthcare burden of epidemic proportions and higher ratesof severe disease. CT is being used extensively to evaluate and diagnose patients with CDAD,although CT findings are often variable and non-specific. Three prior studies have examinedthe correlation between specific CT findings and severity of clinical disease in CDAD, buthave failed to find any definitive correlations. The purpose of our study is to evaluate therole of CT in determining prognosis in CDAD by correlating specific CT findings withoutcomes such as ICU admission, colectomy and death. Methods: Our retrospective studyanalyzed 106 inpatients with CT scans performed within 7 days of (+) C. difficile toxin assayfrom 1/2005 to 11/2006. Clinical and laboratory parameters of these pts were reviewed. CTscans were retrospectively reviewed by a radiologist with >20 years of experience withoutknowledge of prior readings. Statistical analyses were performed comparing CT findingswith clinical parameters and outcomes. Results: Eighty patients (75%) showed CT evidenceof colitis from CDAD. The majority had pancolitis (58 [73%] of 80 pts). Other CT findingssuggestive of colitis included accordion sign (29 pts [36%]), pericolonic stranding (75 pts[94%]), submucosal edema (53 pts [66%]), ascites (23 pts [29%]), bowel dilatation (61 pts[76%]) and pleural effusion (41 pts [51%]). Fifteen pts (15%) required ICU monitoringbecause of CDAD. Eight pts (8%) had colectomy. Death from CDAD was recorded for 10pts (9%) and overall mortality was 20%. Ascites on CT correlated with the need for ICUmonitoring because of CDAD (p < 0.001). The association between pts with accordion signand pleural effusion on CT and the need for ICU monitoring approached statistical signific-ance. Logistic regression analysis showed that the combination of clinical presentation(diarrhea, abdominal pain, nausea/vomiting and fever) with lab values (WBC, HCO3, BUN,Cr) at the time of CDAD diagnosis and presence of ascites on CT have predictive value forthe need for ICU monitoring (p < 0.002). Conclusions: The majority of pts with CDADhave CT evidence of colitis, mostly pancolitis. The finding of ascites on CT appears to beindependently correlated to the need for ICU monitoring. There may be predictive valuein grouping clinical presentation, initial lab values and ascites on CT for determining prognosisin CDAD.

S1159

Blood Flow Assessed By Perfusion CT Reflects Angiogenesis and Correlateswith Prognostic Factors in pts with Pancreatic Endocrine TumorsGaspard d'Assignies, Anne Couvelard, S. Bahrami, Marie Pierre Vullierme, PascalHammel, Philippe Lévy, Alain Sauvanet, Philippe B. Ruszniewski, Valérie Vilgrain

Purpose To prospectively correlate multidetector computed tomographic (CT) perfusionmeasurement of endocrine pancreatic tumors and tumor's microvascular density assessedby histological techniques and to determine whether perfusion CT parameters differ betweenvarious tumor's grades. Materials And Methods : Thirty six patients (15 males, 19 females;