- Email: [email protected]
Colonoscopy: The positive and the negative
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G. Minoli / Digestive and Liver Disease 38 (2006) 918–920
Commentary
Colonoscopy: The positive and the negative G. Minoli Gastroenterology Division, Valduce Hospital, Via Dante 11-22100 Como, Italy Available online 18 October 2006
Colonoscopy is considered the ‘gold standard’ for detecting colorectal neoplasia, and is increasingly viewed as a primary screening approach for these cancers [1]. However, it may fail to detect clinically important neoplastic lesions. Three large retrospective studies [2–4] and one populationbased analysis [5] consistently showed that in routine clinical practice, miss rates for colorectal cancer at colonoscopy range from 2 to 6%. In the National Polyp Study, experienced endoscopists failed to identify approximately 25% of patients with incidental adenomas [6]. In tandem colonoscopy studies, the pooled miss rate for polyps of any size was 22% [7]. In addition, the sensitivity of this examination for colorectal tumors varies between centres and examiners, causing differences in the quality of performance [8]. Improving quality in the technical execution of colonoscopy is therefore mandatory to boost the impact of this examination on the detection and prevention of colorectal cancer. An essential part of any quality improvement scheme is the identification and measurement of specific quality indicators associated with desirable outcomes. Once these have been established, benchmarks must be agreed, for use as comparators. Benchmarks can serve as a threshold for acceptable performance but also as a ‘best level’ and a goal for improving performance [9,10]. In 2002, the US Multi-Society Task Force on Colorectal Cancer identified specific quality indicators for colonoscopy and established threshold levels for each that could serve as targets for achieving a high-quality procedure, and to facilitate the development of constructive programs for continuous quality improvement (CQI) [11]. CQI is recommended by professional societies as part of every colonoscopy program but little is known about its real effect on the outcomes of the examination [11,12]. Before setting up a CQI program we must know which indicators to measure, and what are the our local values for those indicators are; they must then be compared with the values reported by others and – very important – with our own values from the past, if we are to gauge progress. The international literature provides the indicators. Besides the US Task Force [11] there are the combined efforts E-mail address: [email protected]
of AGC, ASGE and AGA [12–14]. However, we must bear in mind that the literature lists all possible indicators, not just those that lend themselves to routine use, which is what interests us most. To be truly useful, the indicators must be: (1) few, because in everyday practice it is impossible to check a long list; (2) easy to detect and record; (3) above all measurable and quantifiable. We therefore need to select reports that give information on how to measure them and what patterns to expect in everyday practice, outside reference centres. The literature often refers to ideal situations, but what about real life? Are these data only likely to be encountered in reference centres, or can we hope to find them in ‘normal’ hospitals—like where I work? Hence the need for studies giving information like this by our Portuguese colleagues (M Isabelle Cremers, Pedro Marques-Vidal: colonoscopies in Portuguese district hospitals: a multicentric transverse study) [15]. They focussed on real-life situations, i.e. the clinical effectiveness of colonoscopy in everyday work, in everyday departments, with the structures available every day, and everyday endoscopists. They analysed 1245 colonoscopies done in 1 week in 33 district hospitals in Portugal, collecting information mainly (25 hospitals) from computer databases; these 33 hospitals account for about 70% of the colonoscopies done in Portugal. An inevitable limit of this kind of study is the good faith of the people who collect and enter the data: no one can check, for instance, whether the proportion of cases where the scope reportedly reached the cecum is actually true. It is equally difficult – perhaps impossible – to extrapolate the results to other situations on account of differences in ‘culture’, organisation and on what basis patients are referred for the examination. However, the findings can always serve as a stimulus for reflection, which can lead to suggestions for use in other situations. The colleagues did not use the US Task Force indicators [11], but this depended on the information available in the Portuguese database (employed in 25 centres). The indications for the examination help assess its appropriateness. The Portuguese data are much the same as in other reports except for the high percentage of examinations done for polypectomies (a finding that surprised the authors themselves).
G. Minoli / Digestive and Liver Disease 38 (2006) 918–920
Also surprising is that only 12 centres required informed consent from their patients – only for polypectomy in three and for sedation in one – as if in Portugal the idea of the patient being involved in decisions concerning his health has not yet caught on. It is certainly the most unsatisfactory aspect and Portuguese colleagues will have to work hard on this before they are obliged to by the courts and claims for damages. We could not see exactly what was meant by informed consent—but we hope that it is not limited, in the few hospitals where it is required, to the mere bureaucratic request for signature on a form, and that patients are given enough information to enable them to participate in these decisions. Sedation was used very rarely—only about a quarter of the patients received it, and the drugs, routes of administration and timing are not specified. We know there is a big difference between the English-speaking world, where sedation is the rule, and the Northern-European or Japanese areas where it is used much less. This is not the place to go into the reasons—fear of complications, cost considerations, implicit admission of the operator’s lack of skill, or others? We have only to ask whether it is a useful indicator for achieving continuous improvements in quality. I personally have no doubt that sedation can make this an examination that is always well tolerated, and can help overcome the notion – still widely held among patients – that the colonoscope is an instrument of torture! This is even more important in the light of today’s pressing need to convince people to present for screening colonoscopy. Obviously there are patients in whom the examination causes little discomfort but it is hard to identify these beforehand. Then too, not all colonoscopists are equally ‘light-handed’ and even the good ones have their bad days, when quite possibly they also pay less attention to whether they cause pain. There is no proof that sedation raises the risk of complications [16,17] but it does improve the likelihood of reaching the cecum, as reported not only in this article but also by Radaelli et al. [18,19]. Then how does one define the completeness of colonoscopy? On the basis of the endoscopist’s impression – observation of the valve – or of the valve and the appendicular orifice? Does it depend on photographic documentation? What are the reference values? Some say the cecum should be intubated in 90% of all cases and in 95% of those done for screening. But are these percentages of all examinations, or only those done for diagnosis? Of non-operated patients? Of those with adequate preparation—or of those with stenosis? What about those with anatomical abnormalities [12–14,20]? The North American gastroenterological societies, AGA, ASGE and ACG [12–14], have recently established that (1) colonoscopy is complete when the instrument is pushed proximally up to the ileocecal valve so as to show the part between the medial wall of the cecum and the appendicular orifice; (2) that reaching the valve should be documented, mentioning observation of the valve and the appendicular orifice; (3) that in doubtful cases observation of the lips of the valve, or
919
ileal intubation should be described; (4) that photographic documentation should be recommended; (5) that the percentage of intubations should include colonoscopies with stenosis but not the failures due to poor preparation or severe inflammation. Similarly, examinations done for distal operative procedures, such as polypectomy, placing a stent, or dilatation of a stenosis, should not be counted. The Portuguese authors talk of completeness in 69.6% of cases, but this rises to nearly 75% if one excludes examinations for polypectomy, which comes close, for example, to a British report [21]. However, there is also a more ‘expressive’ way of reporting data on completeness: this involves calculating the number of centres where the cecum is not reached in a satisfactory proportion of cases. In one Italian study (unpublished data), only 22% of centres reached the end of the cecum in more than 90% of cases, though the mean proportion for reaching this point – defined as observation of the valve – was 82% [18,19]. The quality of intestinal preparation is confirmed as crucial [22,23]. The Portuguese found the preparation was ‘good’ in only half the patients, applying non-standardised definitions. The ASGE [12,13] defines as good a preparation with ‘no or minimal solid stool with large amounts of clear fluid requiring suction’ and recommends that ‘the procedure be considered adequate if it allows (within the technical limitations of the procedure) detection of polyps 5 mm or larger’. Here, the Portuguese scientific societies have plenty of work on their slate. What other indicators do the scientific authorities recommend? Certainly the most important and usable, besides reaching the cecum, include the polyp detection rate, the time taken to extract the instrument, and the post-polypectomy surveillance times [12]. At the present stage of our organisational and cultural capacities we can never stress enough the importance of ‘measuring to count’. The Italian AIGO study found that half the units surveyed had systematic programs for recording their outcomes, as the indispensable groundwork for a CQI program [18,19]. Often just ‘measuring’ is enough to improve outcomes [24]. There is only one path for improving the quality of medical performance—it is long and compulsory and we are only just starting out. It may even be a bit painful, especially for the older practitioners who suffer Freudian angst as they see their much-maligned convictions (‘I am the doctor and I do whatever I want’) lose ground. In the USA, the idea of ‘P4P’ (pay for performance) is catching on, meaning payment in proportion to the quality of the procedure, not just its execution [25]. Will this become necessary in other health care models? Will it be possible—or desirable? It is our duty to do everything possible to be ready.
Conflict of interest statement None declared.
920
G. Minoli / Digestive and Liver Disease 38 (2006) 918–920
References [1] Rex DK. Colonoscopy. Gastrointest Endosc Clin N Am 2000; 10:135–60. [2] Rex DK, Rahmani EY, Haseman JH, Lemmel GT, Kaster S, Buckley JS, et al. Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice. Gastroenterology 1997;112:17–23. [3] Hosokawa O, Shirasaki S, Kaizaki Y, Hayashi H, Douden K, Hattori M. Invasive colorectal cancer detected up to 3 years after a colonoscopy negative for cancer. Endoscopy 2003;35:506–10. [4] Leaper M, Johnston MJ, Barclay M, Dobbs BR, Frizelle FA. Reasons for failure to diagnose colorectal carcinoma at colonoscopy. Endoscopy 2004;36:499–503. [5] Bressler B, Paszat LF, Vinden C, Li C, He J, Rabeneck L. Colonoscopic miss rates for right-sided colon cancer: a population-based analysis. Gastroenterology 2004;127:452–6. [6] Winawer SJ, Zauber AG, O’Brien MJ, Ho MN, Gottlieb L, Sternberg SS, et al. Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. N Engl J Med 1993;328:901–6. [7] van Rijn JC, Reitsma JB, Stoker J, Bossuyt PM, van Deventer SJ, Dekker E. Polyp miss rate determined by tandem colonoscopy: a systematic review. Am J Gastroenterol 2006;11:343–50. [8] Haseman JH, Lemmel GT, Rahmani EY, Rex DK. Failure of colonoscopy to detect colorectal cancer: evaluation of 47 cases in 20 hospitals. Gastrointest Endosc 1997;45:451–5. [9] Berwick DM, Nolan TW. Physicians as leaders in improving health care. Ann Intern Med 1998;128:289–92. [10] Johanson JF. Continuous quality improvement in the ambulatory endoscopy center. Gastrointest Endosc Clin N Am 2002;12:351– 65. [11] Rex DK, Bond JH, Winawer S, Levin TR, Burt RW, Johnson DA, et al. US Multi-Society Task Force on Colorectal Cancer. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol 2002;97:1296–308. [12] Rex DK, Petrini J, Todd B, Chak A, Cohen J, Deal ES, et al. Quality indicators for colonoscopy. Gastrointest Endosc IE 2006;63:s16–28. [13] Rex DK, Petrini JL, Baron TH, Chak A, Cohen J, Deal SE, et al. ASGE/ACG Taskforce on Quality in Endoscopy Quality indicators for colonoscopy. Am J Gastroenterol 2006;101:873–85.
[14] Winawer S, Zauber AG, Fletcher RH, Stillman JS, O’Brien MJ, Levin B, et al. Guidelines for colonoscopy surveillance after polypectomy: a consensus update by the US Multi-Society Task Force on colorectal cancer and the American Cancer Society. Gastroenterology 2006;130:1872–85. [15] Cremers MI, Marques-Vidal P. Colonoscopy in Portuguese district hospitals: A multicentric transverse study. Dig Liver Dis 2006:38. [16] Bowering K, McPhillips J, Vithanarchchi U, Mahindra P, Byrne A, Sturges RK et al. Is sedation practice really linked with adverse endoscopic outcomes? An audit of 7234 procedures in a UH large teaching hospital GIE 2006; 63:AB191. [17] Lieberman DA, Weiss DG, Veterans Affairs Cooperative Study Group 380. One-time screening for colorectal cancer with combined fecal occult-blood testing and examination of the distal colon. N Engl J Med 2001:345555–60. [18] Radaelli F, Meucci G, Bartesaghi G, Minoli G, Associazione Italiana Gastroenterologi & Endoscopisti Ospedalieri. Factors influencing the effectiveness of colonoscopy. Dig Liver Dis 2006;38(Suppl. 1):s37. [19] Radaelli F, Meucci G, Bartesaghi G, Minoli G, Associazione Italiana Gastroenterologi & Endoscopisti Ospedalieri. Sedation practice influences the effectiveness of colonoscopy: Results from a large, multicentre prospective study. Dig Liver Dis 2006;38(Suppl. 1):s144. [20] Rex DK. Qualit`a in Colonoscopy: cecal intubation first, then what? Am J Gastroenterol 2006;101:732–4. [21] Bowles CJA, Leicester R, Ramaya C, Swarbrick E, Williams CB, Epstein O. A prospective study of colonoscopy practice in the UK today: are we adequately prepared for national colorectal cancer screening tomorrow? Gut 2004;553:277–83. [22] Harewood GC, Sharma VK, de Galmo P. Impact of colonoscopy preparation quality on detection of suspected colonic neoplasia. Gastrointest Endosc 2003;58:76–9. [23] Froelich F, Wietslibach V, Gonvers JL, Gonvers JJ, Burnand B, Vader JP, et al. Impact of colonic cleansing on quality and diagnostic yield of colonoscopy: the European Panel of Appropriateness of Gastrointestinal Endoscopy European multicenter study. Gastrointest Endosc 2005;61:378–84. [24] Imperiali G, Minoli G. Monitorare gli outcomes migliora gli outcomes? Clin Governance 2005:36–7. [25] American Gastroenterological Association. AGA Task force in quality in practice: a national overview and implications for GI practice. Gastroenterology 2005;129:361–9. doi: 10.1016/j.dld.2006.09.010
G. Minoli / Digestive and Liver Disease 38 (2006) 918–920
Commentary
Colonoscopy: The positive and the negative G. Minoli Gastroenterology Division, Valduce Hospital, Via Dante 11-22100 Como, Italy Available online 18 October 2006
Colonoscopy is considered the ‘gold standard’ for detecting colorectal neoplasia, and is increasingly viewed as a primary screening approach for these cancers [1]. However, it may fail to detect clinically important neoplastic lesions. Three large retrospective studies [2–4] and one populationbased analysis [5] consistently showed that in routine clinical practice, miss rates for colorectal cancer at colonoscopy range from 2 to 6%. In the National Polyp Study, experienced endoscopists failed to identify approximately 25% of patients with incidental adenomas [6]. In tandem colonoscopy studies, the pooled miss rate for polyps of any size was 22% [7]. In addition, the sensitivity of this examination for colorectal tumors varies between centres and examiners, causing differences in the quality of performance [8]. Improving quality in the technical execution of colonoscopy is therefore mandatory to boost the impact of this examination on the detection and prevention of colorectal cancer. An essential part of any quality improvement scheme is the identification and measurement of specific quality indicators associated with desirable outcomes. Once these have been established, benchmarks must be agreed, for use as comparators. Benchmarks can serve as a threshold for acceptable performance but also as a ‘best level’ and a goal for improving performance [9,10]. In 2002, the US Multi-Society Task Force on Colorectal Cancer identified specific quality indicators for colonoscopy and established threshold levels for each that could serve as targets for achieving a high-quality procedure, and to facilitate the development of constructive programs for continuous quality improvement (CQI) [11]. CQI is recommended by professional societies as part of every colonoscopy program but little is known about its real effect on the outcomes of the examination [11,12]. Before setting up a CQI program we must know which indicators to measure, and what are the our local values for those indicators are; they must then be compared with the values reported by others and – very important – with our own values from the past, if we are to gauge progress. The international literature provides the indicators. Besides the US Task Force [11] there are the combined efforts E-mail address: [email protected]
of AGC, ASGE and AGA [12–14]. However, we must bear in mind that the literature lists all possible indicators, not just those that lend themselves to routine use, which is what interests us most. To be truly useful, the indicators must be: (1) few, because in everyday practice it is impossible to check a long list; (2) easy to detect and record; (3) above all measurable and quantifiable. We therefore need to select reports that give information on how to measure them and what patterns to expect in everyday practice, outside reference centres. The literature often refers to ideal situations, but what about real life? Are these data only likely to be encountered in reference centres, or can we hope to find them in ‘normal’ hospitals—like where I work? Hence the need for studies giving information like this by our Portuguese colleagues (M Isabelle Cremers, Pedro Marques-Vidal: colonoscopies in Portuguese district hospitals: a multicentric transverse study) [15]. They focussed on real-life situations, i.e. the clinical effectiveness of colonoscopy in everyday work, in everyday departments, with the structures available every day, and everyday endoscopists. They analysed 1245 colonoscopies done in 1 week in 33 district hospitals in Portugal, collecting information mainly (25 hospitals) from computer databases; these 33 hospitals account for about 70% of the colonoscopies done in Portugal. An inevitable limit of this kind of study is the good faith of the people who collect and enter the data: no one can check, for instance, whether the proportion of cases where the scope reportedly reached the cecum is actually true. It is equally difficult – perhaps impossible – to extrapolate the results to other situations on account of differences in ‘culture’, organisation and on what basis patients are referred for the examination. However, the findings can always serve as a stimulus for reflection, which can lead to suggestions for use in other situations. The colleagues did not use the US Task Force indicators [11], but this depended on the information available in the Portuguese database (employed in 25 centres). The indications for the examination help assess its appropriateness. The Portuguese data are much the same as in other reports except for the high percentage of examinations done for polypectomies (a finding that surprised the authors themselves).
G. Minoli / Digestive and Liver Disease 38 (2006) 918–920
Also surprising is that only 12 centres required informed consent from their patients – only for polypectomy in three and for sedation in one – as if in Portugal the idea of the patient being involved in decisions concerning his health has not yet caught on. It is certainly the most unsatisfactory aspect and Portuguese colleagues will have to work hard on this before they are obliged to by the courts and claims for damages. We could not see exactly what was meant by informed consent—but we hope that it is not limited, in the few hospitals where it is required, to the mere bureaucratic request for signature on a form, and that patients are given enough information to enable them to participate in these decisions. Sedation was used very rarely—only about a quarter of the patients received it, and the drugs, routes of administration and timing are not specified. We know there is a big difference between the English-speaking world, where sedation is the rule, and the Northern-European or Japanese areas where it is used much less. This is not the place to go into the reasons—fear of complications, cost considerations, implicit admission of the operator’s lack of skill, or others? We have only to ask whether it is a useful indicator for achieving continuous improvements in quality. I personally have no doubt that sedation can make this an examination that is always well tolerated, and can help overcome the notion – still widely held among patients – that the colonoscope is an instrument of torture! This is even more important in the light of today’s pressing need to convince people to present for screening colonoscopy. Obviously there are patients in whom the examination causes little discomfort but it is hard to identify these beforehand. Then too, not all colonoscopists are equally ‘light-handed’ and even the good ones have their bad days, when quite possibly they also pay less attention to whether they cause pain. There is no proof that sedation raises the risk of complications [16,17] but it does improve the likelihood of reaching the cecum, as reported not only in this article but also by Radaelli et al. [18,19]. Then how does one define the completeness of colonoscopy? On the basis of the endoscopist’s impression – observation of the valve – or of the valve and the appendicular orifice? Does it depend on photographic documentation? What are the reference values? Some say the cecum should be intubated in 90% of all cases and in 95% of those done for screening. But are these percentages of all examinations, or only those done for diagnosis? Of non-operated patients? Of those with adequate preparation—or of those with stenosis? What about those with anatomical abnormalities [12–14,20]? The North American gastroenterological societies, AGA, ASGE and ACG [12–14], have recently established that (1) colonoscopy is complete when the instrument is pushed proximally up to the ileocecal valve so as to show the part between the medial wall of the cecum and the appendicular orifice; (2) that reaching the valve should be documented, mentioning observation of the valve and the appendicular orifice; (3) that in doubtful cases observation of the lips of the valve, or
919
ileal intubation should be described; (4) that photographic documentation should be recommended; (5) that the percentage of intubations should include colonoscopies with stenosis but not the failures due to poor preparation or severe inflammation. Similarly, examinations done for distal operative procedures, such as polypectomy, placing a stent, or dilatation of a stenosis, should not be counted. The Portuguese authors talk of completeness in 69.6% of cases, but this rises to nearly 75% if one excludes examinations for polypectomy, which comes close, for example, to a British report [21]. However, there is also a more ‘expressive’ way of reporting data on completeness: this involves calculating the number of centres where the cecum is not reached in a satisfactory proportion of cases. In one Italian study (unpublished data), only 22% of centres reached the end of the cecum in more than 90% of cases, though the mean proportion for reaching this point – defined as observation of the valve – was 82% [18,19]. The quality of intestinal preparation is confirmed as crucial [22,23]. The Portuguese found the preparation was ‘good’ in only half the patients, applying non-standardised definitions. The ASGE [12,13] defines as good a preparation with ‘no or minimal solid stool with large amounts of clear fluid requiring suction’ and recommends that ‘the procedure be considered adequate if it allows (within the technical limitations of the procedure) detection of polyps 5 mm or larger’. Here, the Portuguese scientific societies have plenty of work on their slate. What other indicators do the scientific authorities recommend? Certainly the most important and usable, besides reaching the cecum, include the polyp detection rate, the time taken to extract the instrument, and the post-polypectomy surveillance times [12]. At the present stage of our organisational and cultural capacities we can never stress enough the importance of ‘measuring to count’. The Italian AIGO study found that half the units surveyed had systematic programs for recording their outcomes, as the indispensable groundwork for a CQI program [18,19]. Often just ‘measuring’ is enough to improve outcomes [24]. There is only one path for improving the quality of medical performance—it is long and compulsory and we are only just starting out. It may even be a bit painful, especially for the older practitioners who suffer Freudian angst as they see their much-maligned convictions (‘I am the doctor and I do whatever I want’) lose ground. In the USA, the idea of ‘P4P’ (pay for performance) is catching on, meaning payment in proportion to the quality of the procedure, not just its execution [25]. Will this become necessary in other health care models? Will it be possible—or desirable? It is our duty to do everything possible to be ready.
Conflict of interest statement None declared.
920
G. Minoli / Digestive and Liver Disease 38 (2006) 918–920
References [1] Rex DK. Colonoscopy. Gastrointest Endosc Clin N Am 2000; 10:135–60. [2] Rex DK, Rahmani EY, Haseman JH, Lemmel GT, Kaster S, Buckley JS, et al. Relative sensitivity of colonoscopy and barium enema for detection of colorectal cancer in clinical practice. Gastroenterology 1997;112:17–23. [3] Hosokawa O, Shirasaki S, Kaizaki Y, Hayashi H, Douden K, Hattori M. Invasive colorectal cancer detected up to 3 years after a colonoscopy negative for cancer. Endoscopy 2003;35:506–10. [4] Leaper M, Johnston MJ, Barclay M, Dobbs BR, Frizelle FA. Reasons for failure to diagnose colorectal carcinoma at colonoscopy. Endoscopy 2004;36:499–503. [5] Bressler B, Paszat LF, Vinden C, Li C, He J, Rabeneck L. Colonoscopic miss rates for right-sided colon cancer: a population-based analysis. Gastroenterology 2004;127:452–6. [6] Winawer SJ, Zauber AG, O’Brien MJ, Ho MN, Gottlieb L, Sternberg SS, et al. Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. N Engl J Med 1993;328:901–6. [7] van Rijn JC, Reitsma JB, Stoker J, Bossuyt PM, van Deventer SJ, Dekker E. Polyp miss rate determined by tandem colonoscopy: a systematic review. Am J Gastroenterol 2006;11:343–50. [8] Haseman JH, Lemmel GT, Rahmani EY, Rex DK. Failure of colonoscopy to detect colorectal cancer: evaluation of 47 cases in 20 hospitals. Gastrointest Endosc 1997;45:451–5. [9] Berwick DM, Nolan TW. Physicians as leaders in improving health care. Ann Intern Med 1998;128:289–92. [10] Johanson JF. Continuous quality improvement in the ambulatory endoscopy center. Gastrointest Endosc Clin N Am 2002;12:351– 65. [11] Rex DK, Bond JH, Winawer S, Levin TR, Burt RW, Johnson DA, et al. US Multi-Society Task Force on Colorectal Cancer. Quality in the technical performance of colonoscopy and the continuous quality improvement process for colonoscopy: recommendations of the US Multi-Society Task Force on Colorectal Cancer. Am J Gastroenterol 2002;97:1296–308. [12] Rex DK, Petrini J, Todd B, Chak A, Cohen J, Deal ES, et al. Quality indicators for colonoscopy. Gastrointest Endosc IE 2006;63:s16–28. [13] Rex DK, Petrini JL, Baron TH, Chak A, Cohen J, Deal SE, et al. ASGE/ACG Taskforce on Quality in Endoscopy Quality indicators for colonoscopy. Am J Gastroenterol 2006;101:873–85.
[14] Winawer S, Zauber AG, Fletcher RH, Stillman JS, O’Brien MJ, Levin B, et al. Guidelines for colonoscopy surveillance after polypectomy: a consensus update by the US Multi-Society Task Force on colorectal cancer and the American Cancer Society. Gastroenterology 2006;130:1872–85. [15] Cremers MI, Marques-Vidal P. Colonoscopy in Portuguese district hospitals: A multicentric transverse study. Dig Liver Dis 2006:38. [16] Bowering K, McPhillips J, Vithanarchchi U, Mahindra P, Byrne A, Sturges RK et al. Is sedation practice really linked with adverse endoscopic outcomes? An audit of 7234 procedures in a UH large teaching hospital GIE 2006; 63:AB191. [17] Lieberman DA, Weiss DG, Veterans Affairs Cooperative Study Group 380. One-time screening for colorectal cancer with combined fecal occult-blood testing and examination of the distal colon. N Engl J Med 2001:345555–60. [18] Radaelli F, Meucci G, Bartesaghi G, Minoli G, Associazione Italiana Gastroenterologi & Endoscopisti Ospedalieri. Factors influencing the effectiveness of colonoscopy. Dig Liver Dis 2006;38(Suppl. 1):s37. [19] Radaelli F, Meucci G, Bartesaghi G, Minoli G, Associazione Italiana Gastroenterologi & Endoscopisti Ospedalieri. Sedation practice influences the effectiveness of colonoscopy: Results from a large, multicentre prospective study. Dig Liver Dis 2006;38(Suppl. 1):s144. [20] Rex DK. Qualit`a in Colonoscopy: cecal intubation first, then what? Am J Gastroenterol 2006;101:732–4. [21] Bowles CJA, Leicester R, Ramaya C, Swarbrick E, Williams CB, Epstein O. A prospective study of colonoscopy practice in the UK today: are we adequately prepared for national colorectal cancer screening tomorrow? Gut 2004;553:277–83. [22] Harewood GC, Sharma VK, de Galmo P. Impact of colonoscopy preparation quality on detection of suspected colonic neoplasia. Gastrointest Endosc 2003;58:76–9. [23] Froelich F, Wietslibach V, Gonvers JL, Gonvers JJ, Burnand B, Vader JP, et al. Impact of colonic cleansing on quality and diagnostic yield of colonoscopy: the European Panel of Appropriateness of Gastrointestinal Endoscopy European multicenter study. Gastrointest Endosc 2005;61:378–84. [24] Imperiali G, Minoli G. Monitorare gli outcomes migliora gli outcomes? Clin Governance 2005:36–7. [25] American Gastroenterological Association. AGA Task force in quality in practice: a national overview and implications for GI practice. Gastroenterology 2005;129:361–9. doi: 10.1016/j.dld.2006.09.010