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910 A Prospective Study Evaluating the Association Between Timing and Quality of Bowel Preparation for Colonoscopy and Adenoma Detection Rate
Abstracts
805 Complications of Gastrointestinal Endoscopy in 85,391 Procedures Alberto Espino*1,3, Ximena Garcia1,3, Macarena Mac-Namara1, Hugo Richter2,3, Fernando Pimentel2,3, Francisco Biel1,3, Camila Robles1, Matías Callejas1, Allan C. Sharp2,3, Andres Donoso2,3, Roberto Candia1,3, Robinson G. Gonzalez1,3, Nicolas Jarufe2,3, Marco Arrese1,3, Manuel Alvarez-Lobos1,3, Oslando Padilla4 1 Gastroenterology, Pontifical Catholic University of Chile, Santiago, Chile; 2Digestive Surgery, Pontifical Catholic University of Chile, Santiago, Chile; 3The Digestive Endoscopy Center of University Clinical Hospital, Pontifical Catholic University of Chile, Santiago, Chile; 4 Public Health, Pontifical Catholic University of Chile, Santiago, Chile Background: Complications are inherent to GI endoscopy (GIE) and do not necessarily imply endoscopist’s negligence. They may occur even using highest standards of practice. Objectives: To analyze the frequency and severity of complications occurring within 30 days after of the GIE at a single university hospital in Chile. Methods: We reviewed the records about patients who underwent GIE from January 2001 through May 2011. Results: A total of 85,391 GIE were evaluated. Procedures: 46,928 (55%) esophagogastroduodenoscopy (EGD); 27,993 (32.8%) diagnostic colonoscopies; 1427 (1.7%) polypectomies; and other procedures (hemostasis, variceal band ligation (VBL), foreign-body removal, dilation, stents, PEG, ERCP, EUS and double balloon endoscopy) 9043 (10.5%). A total of 299 complications were associated with GIE (59 % female, mean age 63 years, range 5 - 99). The overall complications rate was 0.35% (cardiopulmonary (CP) 0.1%, bleeding 0.07%, perforation 0.06%, infection 0.04%, pancreatitis 0.03% and other). The overall complication rate was higher in therapeutic procedures (TP) vs diagnostic procedures (DP) (2.7% v/s 0.16%, p⬍0.0001). The percentage of severe complications was higher in TP vs DP (52.3% vs 28.4%, p⬍0.0001). The overall complication rate for EGD was 0.14% (CP 0.07%, perforation 0.017%, bleeding 0.019%); diagnostic colonoscopy, 0.27% (CP 0.1%, perforation 0.06%, bleeding 0.02%); and polypectomy, 1.8% (CP 0.14%, perforation 0.28%, bleeding 0.98%). A total of 15 deaths occurred (overall rate 0.018%, 83% in TP). The overall mortality rate was higher in TP vs DP (0.2% v/s 0.003%, p⬍0.0001). The mortality rate for PEG was 0.7%; VBL 0.4%; ERCP 0.2%; diagnostic colonoscopy 0.004%; EGD 0.004%; and polypectomy 0%. Conclusions: GIE is associated with complications and mortality. The severity and risk of complications are higher in therapeutic procedures. These risks should be clearly explained to patients and their family before the procedure.
910 A Prospective Study Evaluating the Association Between Timing and Quality of Bowel Preparation for Colonoscopy and Adenoma Detection Rate Kidist Yimam*, Edward W. Holt, Hanley Ma, Richard E. Shaw, Richard Sundberg, Michael S. Verhille Gastroenterology, California Pacific Medical Center, San Francisco, CA Background: Observational data has shown an inverse relationship between adenoma detection rate (ADR) and interval colon cancer (⬍5 years after colonoscopy). Recent evidence links split-dose bowel prep to higher quality bowel prep and higher polyp detection rates (PDR) than when day-before prep is used. The association between the timing and quality of prep and adenoma yield has not been studied in the right colon alone.Purpose: To evaluate the relationship between the timing of prep (last prep intake to start of colonoscopy) and both the quality of prep and ADR. Methods: We prospectively enrolled patients undergoing outpatient colonoscopy from March to July 2011. Patients documented the time they last consumed prep in a questionnaire. Colonoscopy reports were used to calculate prep-to-colonoscopy interval and quality of prep (Ottawa scale). ADR was calculated from pathology reports. Kendall’s tau-b test was used to identify factors associated with detection of polyps and adenomas. Multiple logistic regression was used to determine independent predictors of polyp and adenoma detection in the entire colon and the right colon. Results: 430 patients were enrolled in the study. Mean age was 60.4 (24-84) years and 211 participants (49.1%) were male. Mean prep-to-colonoscopy interval was 4.6 hours (1.0-13.9). Average Ottawa score was 2.41 (0-11). Prep was rated excellent (Ottawa score 4 or less) in 87.3% of procedures. Overall PDR was 57.4% and ADR was 44%. 35.5% of adenomas were in the right colon (cecum or ascending colon). In a univariate analysis, shorter prep-to-colonoscopy interval was associated with lower Ottawa scores in both the right colon (p⫽0.017) and the entire colon (p⫽0.038). Lower Ottawa scores in the right colon were associated with higher ADR in the right colon (p⫽ 0.047), but this was not reproduced for the entire colon. Lower Ottawa scores in the right colon still predicted ADR in the right colon in a multivariate analysis (p⫽0.009). When comparing prep-tocolonoscopy intervals of Table 1. Mean Ottawa score for entire colon, right, mid, rectosigmoid colon, and Ottawa fluid score for entire colon in patients with prep-end-colonoscopy
www.giejournal.org
interval < 6 hours vs. >6 hours (ANOVA test of means)
Entire colon (0-14) Right colon (0-4) Mid colon (0-4) Rectosigmoid (0-4) Entire colon fluid score (0-2)
< 6 hours Mean Ottawa score (SD) (nⴝ377)
> 6 hours Mean Ottawa score (SD) (nⴝ40)
p-value
2.29 (1.841) 0.51 (0.748) 0.45 (0.621) 0.48 (0.652) 0.85 (0.464)
3.35 (2.476) 0.97 (0.811) 0.70 (0.823) 0.87 (0.853) 0.83 (0.636)
0.001 ⬍0.001 0.020 ⬍0.001 0.788
911 Development of an Online Calculator to Predict Sub-Optimal Bowel Preparation Among Patients Scheduled for Colonoscopy Rusha Modi2, Hank S. Wang*1, Gobind N. Sharma2, Luis H. Ocampo2, Michael D. Baek2, Aaron Lee2, Jessica Liu2, Scott Kubomoto2, Nattapaun N. Thepyasuwan2, Alexander Levy2, Michelle Vu2, Victoria Sheen1, Mary A. Atia2, Kamyar Shahedi3, Bradley J. Snyder1, Poyrung Poysophon1, Brennan M. Spiegel1 1 Digestive Diseases, VA/UCLA, Los Angeles, CA; 2Gastroenterology, Cedars Sinai/VA, Los Angeles, CA; 3Gastroenterology, Olive View Medical Center, Los Angeles, CA Background: The success of colonoscopy depends on high quality bowel preparation; yet inadequate prep is common. We previously found that intensive patient education can improve prep (Spiegel 2011;106:875). However, provision of instructional materials is resource-intensive and unnecessary for those who would otherwise prepare successfully. Although individual predictors of suboptimal prep are known (e.g. diabetes, male), they have not been incorporated into an integrated predictive model. We sought to develop a score that could help providers identify patients at highest risk for sub-optimal prep. Methods: To develop an individualized sub-optimal prep prediction score, we first collected data on poor prep predictors in a cohort of colonoscopy appointments in a University-based VA from 2005-2011. We defined sub-optimal prep as a score ⱕ4 on a 6-point Likert scale. We evaluated 41 hypothesized predictors of suboptimal prep, including demographics (age, sex, race), co-morbidities, social habits (smoking, substance abuse), medications, and procedure traits (indication, month, day, time). We first identified unadjusted predictors of sub-optimal prep, and then entered these into a multivariable logistic model. We performed bestsubset analysis to optimize parsimony, and logit modeling to identify a test cutpoint maximizing specificity over sensitivity while preserving area under the receiver operating characteristics curve (measured with c statistic). Results: There were 2521 colonoscopies (mean patient age⫽62⫾10; 96% men; 50% white; 29% black). 55% had sub-optimal prep. An 8-variable model predicting sub-optimal prep achieved a c-statistic of 0.64 and included afternoon appointment time, Friday procedure, non-screening indication, insulin-dependent diabetes, history of constipation, positive fecal occult blood or immunohistochemistry test, iron deficiency anemia, and black race. Using a threshold of 75 points on a 0-100 scale, the prediction score achieved a specificity and positive predictive value of 92% and 80%, respectively. Of 392 patients testing “positive” for sub-optimal prep risk, fully 314 actually presented as such (i.e. high specificity). In contrast, sensitivity was low at 20%. The calculator is available at: www.ResearchCore.org/ Prep_Predictor. Discussion: We developed an online calculator with an 80% positive predictive value and 92% specificity for sub-optimal prep. While limited in sensitivity, our model identifies patients for whom targeted interventions may yield substantial benefits while minimizes over treatment of inadequate prep. This cost-effective approach is based on patient and procedural traits, suggesting attempts to categorically improve bowel prep must address both individual and system level variables.
912 Variations in Proximal Serrated Polyp Detection Between Endoscopists Are Caused by Withdrawal Time and Not by the Quality of the Bowel Preparation Thomas R. De Wijkerslooth*1, Esther M. Stoop2, Patrick M. Bossuyt3, Kristien M. Tytgat1, Jan Dees2, Elisabeth M. Mathus-Vliegen1, Ernst J. Kuipers2, Paul Fockens1, Monique Van Leerdam2, Evelien Dekker1 1 Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, Netherlands; 2Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, Netherlands; 3Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam, Netherlands Background: Presence of serrated polyps in the proximal colon is associated with synchronous and likely metachronous advanced neoplasia. This might
Volume 75, No. 4S : 2012
GASTROINTESTINAL ENDOSCOPY
AB170
805 Complications of Gastrointestinal Endoscopy in 85,391 Procedures Alberto Espino*1,3, Ximena Garcia1,3, Macarena Mac-Namara1, Hugo Richter2,3, Fernando Pimentel2,3, Francisco Biel1,3, Camila Robles1, Matías Callejas1, Allan C. Sharp2,3, Andres Donoso2,3, Roberto Candia1,3, Robinson G. Gonzalez1,3, Nicolas Jarufe2,3, Marco Arrese1,3, Manuel Alvarez-Lobos1,3, Oslando Padilla4 1 Gastroenterology, Pontifical Catholic University of Chile, Santiago, Chile; 2Digestive Surgery, Pontifical Catholic University of Chile, Santiago, Chile; 3The Digestive Endoscopy Center of University Clinical Hospital, Pontifical Catholic University of Chile, Santiago, Chile; 4 Public Health, Pontifical Catholic University of Chile, Santiago, Chile Background: Complications are inherent to GI endoscopy (GIE) and do not necessarily imply endoscopist’s negligence. They may occur even using highest standards of practice. Objectives: To analyze the frequency and severity of complications occurring within 30 days after of the GIE at a single university hospital in Chile. Methods: We reviewed the records about patients who underwent GIE from January 2001 through May 2011. Results: A total of 85,391 GIE were evaluated. Procedures: 46,928 (55%) esophagogastroduodenoscopy (EGD); 27,993 (32.8%) diagnostic colonoscopies; 1427 (1.7%) polypectomies; and other procedures (hemostasis, variceal band ligation (VBL), foreign-body removal, dilation, stents, PEG, ERCP, EUS and double balloon endoscopy) 9043 (10.5%). A total of 299 complications were associated with GIE (59 % female, mean age 63 years, range 5 - 99). The overall complications rate was 0.35% (cardiopulmonary (CP) 0.1%, bleeding 0.07%, perforation 0.06%, infection 0.04%, pancreatitis 0.03% and other). The overall complication rate was higher in therapeutic procedures (TP) vs diagnostic procedures (DP) (2.7% v/s 0.16%, p⬍0.0001). The percentage of severe complications was higher in TP vs DP (52.3% vs 28.4%, p⬍0.0001). The overall complication rate for EGD was 0.14% (CP 0.07%, perforation 0.017%, bleeding 0.019%); diagnostic colonoscopy, 0.27% (CP 0.1%, perforation 0.06%, bleeding 0.02%); and polypectomy, 1.8% (CP 0.14%, perforation 0.28%, bleeding 0.98%). A total of 15 deaths occurred (overall rate 0.018%, 83% in TP). The overall mortality rate was higher in TP vs DP (0.2% v/s 0.003%, p⬍0.0001). The mortality rate for PEG was 0.7%; VBL 0.4%; ERCP 0.2%; diagnostic colonoscopy 0.004%; EGD 0.004%; and polypectomy 0%. Conclusions: GIE is associated with complications and mortality. The severity and risk of complications are higher in therapeutic procedures. These risks should be clearly explained to patients and their family before the procedure.
910 A Prospective Study Evaluating the Association Between Timing and Quality of Bowel Preparation for Colonoscopy and Adenoma Detection Rate Kidist Yimam*, Edward W. Holt, Hanley Ma, Richard E. Shaw, Richard Sundberg, Michael S. Verhille Gastroenterology, California Pacific Medical Center, San Francisco, CA Background: Observational data has shown an inverse relationship between adenoma detection rate (ADR) and interval colon cancer (⬍5 years after colonoscopy). Recent evidence links split-dose bowel prep to higher quality bowel prep and higher polyp detection rates (PDR) than when day-before prep is used. The association between the timing and quality of prep and adenoma yield has not been studied in the right colon alone.Purpose: To evaluate the relationship between the timing of prep (last prep intake to start of colonoscopy) and both the quality of prep and ADR. Methods: We prospectively enrolled patients undergoing outpatient colonoscopy from March to July 2011. Patients documented the time they last consumed prep in a questionnaire. Colonoscopy reports were used to calculate prep-to-colonoscopy interval and quality of prep (Ottawa scale). ADR was calculated from pathology reports. Kendall’s tau-b test was used to identify factors associated with detection of polyps and adenomas. Multiple logistic regression was used to determine independent predictors of polyp and adenoma detection in the entire colon and the right colon. Results: 430 patients were enrolled in the study. Mean age was 60.4 (24-84) years and 211 participants (49.1%) were male. Mean prep-to-colonoscopy interval was 4.6 hours (1.0-13.9). Average Ottawa score was 2.41 (0-11). Prep was rated excellent (Ottawa score 4 or less) in 87.3% of procedures. Overall PDR was 57.4% and ADR was 44%. 35.5% of adenomas were in the right colon (cecum or ascending colon). In a univariate analysis, shorter prep-to-colonoscopy interval was associated with lower Ottawa scores in both the right colon (p⫽0.017) and the entire colon (p⫽0.038). Lower Ottawa scores in the right colon were associated with higher ADR in the right colon (p⫽ 0.047), but this was not reproduced for the entire colon. Lower Ottawa scores in the right colon still predicted ADR in the right colon in a multivariate analysis (p⫽0.009). When comparing prep-tocolonoscopy intervals of Table 1. Mean Ottawa score for entire colon, right, mid, rectosigmoid colon, and Ottawa fluid score for entire colon in patients with prep-end-colonoscopy
www.giejournal.org
interval < 6 hours vs. >6 hours (ANOVA test of means)
Entire colon (0-14) Right colon (0-4) Mid colon (0-4) Rectosigmoid (0-4) Entire colon fluid score (0-2)
< 6 hours Mean Ottawa score (SD) (nⴝ377)
> 6 hours Mean Ottawa score (SD) (nⴝ40)
p-value
2.29 (1.841) 0.51 (0.748) 0.45 (0.621) 0.48 (0.652) 0.85 (0.464)
3.35 (2.476) 0.97 (0.811) 0.70 (0.823) 0.87 (0.853) 0.83 (0.636)
0.001 ⬍0.001 0.020 ⬍0.001 0.788
911 Development of an Online Calculator to Predict Sub-Optimal Bowel Preparation Among Patients Scheduled for Colonoscopy Rusha Modi2, Hank S. Wang*1, Gobind N. Sharma2, Luis H. Ocampo2, Michael D. Baek2, Aaron Lee2, Jessica Liu2, Scott Kubomoto2, Nattapaun N. Thepyasuwan2, Alexander Levy2, Michelle Vu2, Victoria Sheen1, Mary A. Atia2, Kamyar Shahedi3, Bradley J. Snyder1, Poyrung Poysophon1, Brennan M. Spiegel1 1 Digestive Diseases, VA/UCLA, Los Angeles, CA; 2Gastroenterology, Cedars Sinai/VA, Los Angeles, CA; 3Gastroenterology, Olive View Medical Center, Los Angeles, CA Background: The success of colonoscopy depends on high quality bowel preparation; yet inadequate prep is common. We previously found that intensive patient education can improve prep (Spiegel 2011;106:875). However, provision of instructional materials is resource-intensive and unnecessary for those who would otherwise prepare successfully. Although individual predictors of suboptimal prep are known (e.g. diabetes, male), they have not been incorporated into an integrated predictive model. We sought to develop a score that could help providers identify patients at highest risk for sub-optimal prep. Methods: To develop an individualized sub-optimal prep prediction score, we first collected data on poor prep predictors in a cohort of colonoscopy appointments in a University-based VA from 2005-2011. We defined sub-optimal prep as a score ⱕ4 on a 6-point Likert scale. We evaluated 41 hypothesized predictors of suboptimal prep, including demographics (age, sex, race), co-morbidities, social habits (smoking, substance abuse), medications, and procedure traits (indication, month, day, time). We first identified unadjusted predictors of sub-optimal prep, and then entered these into a multivariable logistic model. We performed bestsubset analysis to optimize parsimony, and logit modeling to identify a test cutpoint maximizing specificity over sensitivity while preserving area under the receiver operating characteristics curve (measured with c statistic). Results: There were 2521 colonoscopies (mean patient age⫽62⫾10; 96% men; 50% white; 29% black). 55% had sub-optimal prep. An 8-variable model predicting sub-optimal prep achieved a c-statistic of 0.64 and included afternoon appointment time, Friday procedure, non-screening indication, insulin-dependent diabetes, history of constipation, positive fecal occult blood or immunohistochemistry test, iron deficiency anemia, and black race. Using a threshold of 75 points on a 0-100 scale, the prediction score achieved a specificity and positive predictive value of 92% and 80%, respectively. Of 392 patients testing “positive” for sub-optimal prep risk, fully 314 actually presented as such (i.e. high specificity). In contrast, sensitivity was low at 20%. The calculator is available at: www.ResearchCore.org/ Prep_Predictor. Discussion: We developed an online calculator with an 80% positive predictive value and 92% specificity for sub-optimal prep. While limited in sensitivity, our model identifies patients for whom targeted interventions may yield substantial benefits while minimizes over treatment of inadequate prep. This cost-effective approach is based on patient and procedural traits, suggesting attempts to categorically improve bowel prep must address both individual and system level variables.
912 Variations in Proximal Serrated Polyp Detection Between Endoscopists Are Caused by Withdrawal Time and Not by the Quality of the Bowel Preparation Thomas R. De Wijkerslooth*1, Esther M. Stoop2, Patrick M. Bossuyt3, Kristien M. Tytgat1, Jan Dees2, Elisabeth M. Mathus-Vliegen1, Ernst J. Kuipers2, Paul Fockens1, Monique Van Leerdam2, Evelien Dekker1 1 Gastroenterology and Hepatology, Academic Medical Center, Amsterdam, Netherlands; 2Gastroenterology and Hepatology, Erasmus University Medical Center, Rotterdam, Netherlands; 3Clinical Epidemiology and Biostatistics, Academic Medical Center, Amsterdam, Netherlands Background: Presence of serrated polyps in the proximal colon is associated with synchronous and likely metachronous advanced neoplasia. This might
Volume 75, No. 4S : 2012
GASTROINTESTINAL ENDOSCOPY
AB170