1050

Which Non-Invasive Disease Activity Index Should Be Used in UlcerativeColitis? A Systematic Head-to-Head Psychometric ComparisonDan Turner, Cynthia H. Seow, Mark S. Silverberg, Gordon R. Greenberg, Anne M.Griffiths, A. Hillary Steinhart

Background: Several non-invasive indices are available to measure disease activity in ulcerativecolitis (UC), but sparse evidence exists to guide their use. We aimed to systematicallycompare the psychometric properties of all existing indices and to determine cutoff scoresthat correspond to remission and response. Methods: In this prospective longitudinal study,86 adults with UC were recruited (52% males, mean age 37.6 ± 13.7 years, median diseaseduration 6.6 (2.1-13.1) years). Items from the following indices were scored: Mayo score,Rachmilewitz, Lichtiger, Seo, Pediatric UC Activity Index (PUCAI), Partial Powell-Tuck,Endoscopic-Clinical Correlation Index (ECCI), Beattie, and Walmsley (SCCAI). Physicianglobal assessment, colonoscopic score, blood tests and the Mayo score were used to assessconstruct and discriminative validity. Follow-up evaluation of 61 patients was used to assesstest-retest reliability and responsiveness. Results: The PUCAI and Walmsley indices rankedthe best for each of the four psychometric properties evaluated. For construct validity, theaverage correlation for the five included constructs were r=0.79 and r=0.80 for the PUCAIandWalmsley respectively (both p<0.001); discriminative validity AUC=0.95 (95% CI, 0.90-0.99) and AUC=0.93 (95% CI, 0.87-0.98); test-retest reliability ICC=0.89 (95%CI, 0.76-0.95) and ICC=0.94 (95% CI, 0.86-0.97) and responsiveness AUC=0.84 (95% CI, 0.72-0.96) and AUC=0.86 (95%CI, 0.74-0.99) respectively. The partial Mayo score ranked wellon three of the four properties evaluated: construct validity r=0.79 (p<0.001); discriminativevalidity AUC=0.95 (95% CI, 0.90-0.99); and responsiveness AUC=0.84 (95%CI, 0.72-0.96).However, this index demonstrated inferior test-retest reliability ICC=0.82 (95% CI, 0.60-0.92). The Rachmilewitz index showed good validity (construct validity r=0.81 (p<0.001);discriminative validity AUC 0.92 (95% CI, 0.87-0.98) and reliability ICC=0.89 (95% CI,0.76-0.95) but inferior responsiveness AUC=0.74 (95%CI, 0.58-0.90). Cutoff scores thatdefine clinical-endoscopic remission and response were determined using ROC curve analysisfor all instruments and were broadly similar to those cutoffs that had been empiricallyderived and used with each of the instruments. Conclusion: The Walmsley, PUCAI andpartial Mayo are valid, reliable and responsive non-invasive indices to assess disease activityin adult UC. Given their robust psychometric properties, these instruments may permit lessfrequent endoscopic assessment in clinical practice and in research.

1051

Assessment of Wireless Capsule Endoscopy in Patients with Ulcerative ColitisDavid T. Rubin, Marc Schwartz, Jami A. Rothe, Bonnie L. Surma, Sam Gavzy, Alana P.Bunnag, Andrew S. Ross

Background: Approximately 10-15% of patients with colitis are classified as indeterminatedue tomixed features at diagnosis or during subsequent treatment and follow-up. In addition,some patients thought to have UC develop Crohn's disease (CD) after surgery. Wirelesscapsule endoscopy (WCE) provides a highly sensitive examination of the small bowel, andhas been shown to have superior yield in known or suspected CD, but has not been studiedprospectively in UC. Objective: The aim of this prospective study was to determine theprevalence of small bowel findings with WCE in adult patients with a clinical diagnosis ofUC. Methods: Patients with clinical, endoscopic and histologic evidence of UC and noevidence of terminal ileitis (by ileoscopy or radiographic study) underwent WCE. Diseaseactivity was assessed using the Simple Clinical Colitis Activity Index (SCCAI) and serologictesting with Serology 7 (Prometheus Laboratories, San Diego, CA) was performed. Twoexperienced examiners blinded to patient history independently assessed the WCE findings.Discrepancies were resolved by meeting and review. Small bowel findings were convertedto Lewis Scores (<135 is “normal”), and compared to SCCAI and serology results. Results:Thirty-six patients met screening criteria and participated in the study. 19 (53%) were male,and 24 (67%) were non-smokers, 7 (19%) ex-smokers and 5 smokers < 1ppd. Patients weremedian 43y old (range: 18-78y), with median age of onset 29y (12-54y) and median durationof disease 10y (0-37y). Twenty-four patients had pancolitis, 11 had left-sided disease and1 had proctitis. The median SCCAI score was 5 (1-13) and 14 patients (39%) had score >7. Median small bowel transit time was 199.5 min (65-374 min). Serology 7 predicted UCin 13 patients, CD in 12 patients and no IBD in 11 patients. No patient had an abnormalLewis Score (mean score=1.2 (SD 5)), but 2 patients had a single pinpoint erosion (serologypredicted UC) and 1 patient (with prior negative ileoscopy) had an ileal ulcer <1/4 of thelumen (serology predicted CD). SCCAI did not correlate with these findings and review ofindividual titers did not change this assessment. Conclusions: In this series of well-definedadult UC patients with various degrees of clinical activity, WCE and Lewis Scoring did notidentify small bowel findings of significance and did not change the diagnosis in 97% ofthese patients. In this cohort of patients, the sensitivity of Serology 7 for UC was only 37%.These findings have important clinical implications for diagnosis and management decisions.

1052

Abnormal Counts of Small Bowel Bacteria or Abnormal Lactulose HydrogenBreath Test in Irritable Bowel Syndrome: Relevance for Symptoms?Iris Posserud, Per-Ove Stotzer, Hasse Abrahamsson, Magnus Simren

Abnormal lactulose hydrogen breath tests (LHBT) indicating abnormal counts of small bowelbacteria are proposed to be common in irritable bowel syndrome (IBS). In a recent study,culture verified small intestinal bacterial overgrowth (SIBO) was rare in IBS, but a proportionof patients had mildly increased counts of small bowel bacteria compared with controls(Posserud et al. Gut 2007). However, the clinical importance of abnormal counts of smallbowel bacteria as indicated by LHBT or culture remains unclear. AIM: Assess the relevanceof abnormal counts of small bowel bacteria and symptoms in IBS. METHODS: Jejunalcultures were obtained from 126 IBS patients (mean age 36 years; 92 females). Another 80IBS patients (mean age 40 years; 63 females) underwent a LHBT. All patients completedvalidated questionnaires assessing IBS symptoms and stool consistency and frequency. SIBO

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was defined as ≥105 colonic bacteria/ml fluid and mildly increased bacteria was defined as>5x103 bacteria/ml or ≥5x103 colonic bacteria/ml (Posserud et al. Gut 2007). For the LHBTa double peak pattern or a >20 ppm H2 rise within 90 min was considered abnormal(Pimentel et al. Am J G 2003). RESULTS: SIBO was found in 4 patients (3%), whereas≥5x103 colonic bacteria/ml was seen in 11 patients (9%), and >5x103 bacteria/ml in 32patients (25%). No significant differences in symptoms were reported by patients with andwithout SIBO. Patients with >5x103 bacteria/ml had looser stools (4.6±1.1 vs 4.0±1.2; p<.05)and tended to have less severe abdominal pain (3.1±0.8 vs 3.5±1.1; p=.05) than patientswith normal small bowel bacterial counts. Having≥5x103 colonic bacteria/ml was associatedwith more severe dyspeptic symptoms (3.3±1.7 vs 2.2±1.2; p<.05). The LHBT of 5 patients(6%) showed a double peak pattern, whereas 34 patients (43%) had a single H2 increasewithin 90 min. A LHBT with a double peak pattern was not associated with any specificsymptoms. Patients with a H2 rise within 90 min reported more severe symptoms of diarrhea(4.6±1.4 vs 3.2±1.6; p<.05) and looser stools (5.1±0.9 vs 4.0±0.9; p<.05) compared topatients with a normal LHBT. Overall symptom severity was not different in patients withnormal and abnormal LHBTs. CONCLUSIONS: We found no clear associations betweensymptoms or symptom severity and culture verified SIBO, mildly increased small bowelbacteria or abnormal LHBT. A H2 rise within 90 min was associated with looser stools andmore severe symptoms of diarrhea, possibly as a consequence of faster small bowel transitin these patients. Thus, the clinical importance of abnormal small bowel bacterial countsin IBS patients is questionable.

1053

Risk Exposures for Functional Dyspepsia Versus IBS in Latin America: APopulation-Based Study in NicaraguaEdgar M. Peña, Loreto Cortes, Rodolfo Pena, Paris . Heidt, Douglas Morgan

BACKGROUND: Risk factors for functional dyspepsia (FD) are uninvestigated in LatinAmerica. The University of Nicaragua (UNAN) maintains a population-based epidemiologysurveillance system for western Nicaragua, encompassing 24% (11,000 homes) of the region'spopulation (200,000). As the only Latin American member of the INDEPTH network (globalnetwork of developing nation surveillance systems), UNAN can uniquely conduct population-based investigations in the Latino population. We have demonstrated an association betweenIBS and psychosocial risk exposures (domestic violence, war trauma) in this population.The aim of the study was to delineate the epidemiology of FD in this Latino population.METHODS: We conducted a population-based, cross-sectional survey in western Nicaragua.A random sample was chosen utilizing the UNAN population surveillance system. Thevalidated Spanish Rome II Modular Questionnaire (R2MQ) was used for the identificationof FD cases for comparison with random healthy controls. The validated Spanish ConflictTactics Scales assessed domestic violence and sexual abuse. The war trauma instrument forexposures in the Sandinista Revolution, was previously validated in Nicaragua, with assess-ment of physical or psychological abuse, witnessed executions, and economic loss. Householdsocioeconomic status was assessed with a regionally validated poverty index [Renzi1993],which was calculated with the United Nation's unsatisfied basic needs measurement, basedon housing, sanitation, education, unemployment. Mantel-Haensztel summary ORs werecalculated, controlled for age and gender. RESULTS: In this population-based survey ofrandomly selected subjects (n=1624), the overall prevalence of FD was 10.3%. This preval-ence is higher than reported in western populations, but consistent with clinical experience.As in the case of IBS in this population, exposure to war trauma was a risk factor for FD,OR 2.0 (95%CI, 1.15-3.5). Poverty did not increase the risk of FD, OR 1.1 (95%CI, 0.78-1.7). In contrast to a positive association in IBS, domestic violence was not a risk factor forFD overall, OR 1.1 (95%CI, 0.68-1.8), or among females, OR 0.98 (95%CI, 0.55-1.7).CONCLUSIONS War trauma is an independent risk factor for functional dyspepsia, as forIBS, among Latinos in Nicaragua. Poverty and domestic violence do not appear to beindependently associated. FUNDING: Rome Foundation.

1054

Prevalence of Small Intestinal Bacterial Overgrowth in Irritable BowelSyndrome: Systematic Review and Meta-AnalysisAlexander C. Ford, Nicholas J. Talley, Brennan M. Spiegel, Paul Moayyedi

Introduction: Small intestinal bacterial overgrowth (SIBO) may explain symptoms in indi-viduals with irritable bowel syndrome (IBS). A high prevalence of SIBO in IBS has beenreported. As a result, treatment of IBS with antibiotics has been advocated. However, studydata are conflicting. Methods: We conducted a systematic review and meta-analysis toexamine this issue. MEDLINE and EMBASE were searched up to November 2008 to identifycase series and case-control studies reporting on prevalence of SIBO, according to variousdiagnostic tests, in unselected adults (> 16 years) meeting diagnostic criteria for IBS. Propor-tion of individuals with a presumptive diagnosis of IBS testing positive using lactulose,glucose, or sucrose hydrogen breath tests, or jejunal aspirate and culture, were combinedfor case series and case-control studies to give a pooled prevalence of SIBO, according tothe test used, in subjects meeting diagnostic criteria for IBS. In addition, for case-controlstudies data were pooled for cases and controls, regardless of test used, and pooled prevalenceof SIBO was compared between the two with an odds ratio (OR) and 95% confidenceinterval (CI). All data were pooled using a random effects model. Results: The searchidentified 2542 studies. Of these 16 appeared eligible and were evaluated. Eleven studies,containing 1778 subjects with symptoms suggestive of IBS met eligibility criteria. Six werecase-control studies using healthy members of the general population, or healthy relatives,as controls. Prevalence of SIBO, according to various tests, is reported in the table. Whendata were pooled for cases meeting diagnostic criteria for IBS compared to controls, regardlessof the test used, the OR for SIBO in IBS was 3.6 (95% CI 1.0-12.4, I2 = 83%). Conclusions:Prevalence of SIBO in individuals meeting diagnostic criteria for IBS appeared high, butthere was a large degree of heterogeneity between studies, and no statistically significantincrease in cases compared with controls. When jejunal aspirate and culture, the gold-standard for the diagnosis of SIBO, was used prevalence was only 4%. These data suggesta definite role for SIBO in IBS is debatable.

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