Dig Dis Sci (2014) 59:1726–1732 DOI 10.1007/s10620-014-3262-8
ORIGINAL ARTICLE
Nationwide Variability of Colonoscopy Preparation Instructions Loc Ton • Helen Lee • Pushpak Taunk • Audrey H. Calderwood • Brian C. Jacobson
Received: 16 May 2014 / Accepted: 18 June 2014 / Published online: 2 July 2014 Ó Springer Science+Business Media New York 2014
Abstract Background Patients undergoing colonoscopy are typically provided preparation instructions. However, these are not standardized for type of bowel purgative, dietary restrictions, or management of prescription and nonprescription medications. Aim To examine the degree of variability in colonoscopy instructions across the USA. Methods Collected colonoscopy preparation instructions from endoscopy units that successfully participated in the American Society for Gastrointestinal Endoscopy’s Endoscopy Unit Recognition Program (EURP). Descriptive statistics were used to describe the variability in bowel preparation, dietary restrictions, medication instructions, and other patient advice. Results Preparation instructions were available from 201 (49 %) of 411 EURP units. Split dosing of bowel purgatives was used by 82 % of practices, although 79 units (39 %) offered instructions for both single- and split-dose regimens and 18 % of units relied only on single-dose regimens. Patients were restricted to a clear liquid diet on the day prior to the colonoscopy by 91 % of practices, but other specific dietary instructions (such as avoidance of nuts or legumes) varied. Instructions for the management of anti-thrombotic and anti-platelet agents, nonsteroidal anti-inflammatory drugs and diabetes medications varied widely among practices. Geographic variations in instructions were also observed. Compared to units in the northeast, units in the west were more likely to rely on split-dose
L. Ton H. Lee P. Taunk A. H. Calderwood B. C. Jacobson (&) Boston University Medical Center, 85 East Concord Street, Room 7721, Boston, MA 02118, USA e-mail: [email protected]
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preparations exclusively (p = 0.05) and units in the south were less likely to include instructions on warfarin management (p \ 0.02). Units throughout the USA were less likely to specifically recommend continuing aspirin use compared to the northeast (p \ 0.02). Conclusion Despite national recommendations for use of split-dose bowel purgatives, many practices are still relying on single-dose preparations. Clear liquid diets are widely recommended for the day prior to the colonoscopy, despite a lack of data to support the need for such a strict dietary regimen. Patients receive disparate instructions regarding the management of their medications. These findings suggest a need for more evidence-based and comprehensive colonoscopy preparation instructions. Keywords Variability Colonoscopy Endoscopy Bowel Preparation instructions Endoscopist Ambulatory surgical centers (ASC) Endoscopy Unit Recognition Program (EURP)
Introduction An estimated 11–14 million colonoscopies are performed annually in the USA for a variety of indications, and colonoscopy is now the most relied-upon means of colorectal cancer screening having been performed on more than 53 % of the screening-eligible population in every state [1–3]. Prior to the colonoscopy, patients typically receive instructions on how to prepare for their procedure, including dietary restrictions, proper use of a bowel purgative (usually 2–4 l of an isosmotic or hyperosmotic solution), and any alterations in the use of their usual medications. Current guidelines surrounding preparation for colonoscopy are scant, limited to administration of the
Dig Dis Sci (2014) 59:1726–1732
bowel purgative in a split-dose fashion (i.e., consuming half to three quarters of the purgative the day prior to the procedure and consuming the remainder the morning of the procedure) and the management of anti-platelet and antithrombotic agents [4–6]. We sought to assess the degree of variability in colonoscopy preparation instructions across the USA in order to determine the extent to which existing guidelines are being followed and to identify areas of practice variation that might benefit from further research.
Methods This study was approved by the Institutional Review Board (IRB) at Boston University Medical Center. A list of 411 endoscopy units that successfully participated in the American Society for Gastrointestinal Endoscopy’s (ASGE) Endoscopy Unit Recognition Program (EURP) was obtained from the publically available pages of the ASGE website on January 24, 2013 [7]. The EURP recognizes endoscopy units that, among other requirements, has current accreditation by a recognized accrediting body; has sent a representative to attend the ASGE’s Improving Quality and Safety in Your Endoscopy Unit course; attests that the unit has adopted ASGE and Centers for Disease Control and Prevention privileging, reprocessing and infection control guidelines; and has an ongoing quality improvement program with the measurement of several important quality measures including quality of bowel preparation during colonoscopy and patient satisfaction. The EURP is open to all settings where gastrointestinal endoscopy is performed, including office-based endoscopy units, hospital-based endoscopy units, and ambulatory surgical centers (ASCs). We conducted an internet search to identify each unit’s contact information, and to determine whether online colonoscopy preparation instructions were available from that unit’s own website. We made telephone calls to all endoscopy units that lacked a website or online instructions. After briefly explaining our study and confirming the organization’s name and location, we requested copies of their preparation instructions. If an endoscopy unit (such as an ASC) did not have instructions available at that unit, we requested the contact information of the endoscopist(s) or practice group(s) that performed procedures at that unit. When different instructions were obtained from multiple endoscopists that performed endoscopy at a single EURP unit, we treated all instructions collectively as if they were from a single unit. All calls were made during normal business hours and a maximum of two calls were made to each unit. If we were unable to obtain information after the second call, the unit was excluded from further analysis. A copy of our IRB approval letter was offered to any
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interested participants. Preparation instructions were received by either secured facsimile or e-mail. We collected information about preparation instructions in four distinct categories: bowel purgative and method of administration, dietary instructions, medication instructions, and patient safety and comfort instructions. Bowel purgative methods were categorized as single-dose (i.e., all purgative taken the day prior to, or morning of the procedure), split-dose, or a combination of the two when a unit provided both types of instructions to patients. Dietary restrictions were categorized as either a strict clear liquid diet or a more liberal diet for the day prior to the colonoscopy. Dietary instructions were categorized as having recommendations about specific food items such as nuts, seeds, gelatin, dairy, alcohol, and colored or dyed foods. We also examined the instructions for common medications, such as anti-thrombotic and anti-platelet agents (aspirin, clopidogrel and warfarin), nonsteroidal antiinflammatory drugs (NSAIDs), cardiac medications (antiarrhythmic and antihypertensive agents), diabetes medications (oral hypoglycemic agents and insulin), and iron supplements. Data on patient safety and comfort instructions included information about what to do in the event of difficulties during bowel preparation, what to wear the day of the procedure, and the need to arrange an escort home post-procedure. Descriptive statistics, including frequencies and percentages, were used. We examined the association between geographic region and specific aspects of bowel preparation to calculate odds ratios (OR) with 95 % confidence intervals (CI) using logistic regression with instructions from the northeast serving as the referent (SAS 9.1, Cary, NC).
Results We obtained online instructions from 142 EURP units and received instructions by e-mail and facsimile from an additional 59 units for a total of 201 units (49 %). The remaining 210 units lacked online preparation instructions, failed to return calls or declined to share their preparation instructions. The 201 units were geographically diverse with 45 units from the west, 44 units from the midwest, 50 units from the northeast and 62 units from the south. Among these 201 EURP units, 144 (72 %; 95 % CI 66–78 %) were ASCs, 56 (28 %; 95 % CI 49–63 %) were hospital-based units and 1 (0.5 %; 95 % CI 0–1 %) was an office-based unit. According to information from the ASGE, 59 % (95 % CI 54–64 %) of current EURP designees are ASCs, 34 % (95 % CI 30–38 %) are hospitalbased units and 7 % (95 % CI 5–10 %) are office-based units.
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Fig. 1 Frequency of bowel purgatives recommended for colonoscopy at endoscopy units
Single-dose bowel preparations were used exclusively at 37 units (18 %), split-dose preparations were used exclusively at 85 units (42 %), and both single- and split-dose preparations were used at 79 units (39 %). There was a range of purgatives prescribed, including isosmotic fulland half-volume polyethylene glycol-based preparations and hyperosmotic preparations (Fig. 1). A MiraLAX (MSD Consumer Care, Inc.) plus Gatorade (PepsiCo, Inc.) preparation was offered by 107 units (53 %), magnesium citrate with or without bisacodyl was offered by 41 units (20 %), and a phosphosoda preparation was offered by 17 units (8 %). There were 55 units (27 %) with purgative instructions that varied according to whether colonoscopy appointments were in the morning or afternoon (e.g., single-dose for morning procedures and split-dose for afternoon procedures), but only two units employed a same-day bowel preparation for afternoon procedures. A strict clear liquid diet was assigned for the day preceding colonoscopy by 183 units (91 %) while the remaining 18 units (9 %) offered more liberal diets. Many of these units also recommended against the intake of specific foods including nuts, seeds, pulp, and fiber (66 %); dairy products (84 %); alcohol (35 %); red, blue, green, and/or purple dyed foods (94 %) and gelatin (3 %). Instructions on when to begin avoidance of nuts, seeds, pulp, and fiber ranged from 1 to 10 days (median 3 days) prior to the colonoscopy. Some form of medication instructions were included in 188 units’ (94 %) instructions. Patients were asked to discontinue aspirin at 26 % of units, to continue taking aspirin at 27 % of units, and to consult with their prescribing physician about the need to continue or discontinue aspirin use at 17 % of units. The remaining 30 % of units did not include any information about aspirin use in their instructions. The majority of units recommended
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consulting the prescribing physician for help with management of clopidogrel (67 %) and warfarin (72 %). Only 50 % of units explicitly instructed patients to continue their antiarrhythmic and antihypertensive agents and 60 % of units encouraged discontinuation of iron supplementation. Figures 2 and 3 demonstrate the variability in medication instructions among these 201 endoscopy units, including significant variability in the management of oral hypoglycemic agents and insulin in the days prior to and day of colonoscopy (Fig. 3). There was significant geographic practice variation (Table 1). Compared to units in the northeast, units in the west were more likely to rely on split-dose preparations exclusively (OR 2.27, 95 % CI 1.00–5.18) and units in the south were less likely to include instructions on warfarin management (OR 0.25, 95 % CI 0.08–0.81). Units throughout the USA were less likely to specifically recommend continuing aspirin use compared to the northeast. Regarding patient safety and comfort instructions, 48 % of units provided specific contact information in the event that patients encountered problems with their bowel preparation and 22 % of units recommended products such as petroleum jelly, diaper wipes, zinc oxide cream, and topical phenylephrine creams and ointments to help with skin irritation. For the day of the colonoscopy, some units provided recommendations on appropriate attire (30 %) and information about the duration of the procedure (37 %). Nearly all units (91 %) provided clear instructions to arrange for an escort and transportation home.
Discussion This sampling of instructions from endoscopy units throughout the USA demonstrates significant variability in
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Fig. 2 Frequency of the types of medication instructions included or not included for the management of anti-thrombotic agents, anticoagulants, nonsteroidal anti-inflammatory drugs, cardiac medications, and iron supplementation
Fig. 3 Frequency of the types of medication instructions included or not included for the management of diabetic medications for the day prior to, and day of, colonoscopy
the quantity and content of information provided to patients regarding preparation for colonoscopy. We found variation in nearly every aspect of colonoscopy preparation including how to use the bowel purgative, what foods to avoid and when, how to manage other prescribed medications, and how to cope with the difficulties of the preparation. We also found an association between some aspects of bowel preparation and geographic location. In some cases, variability may reflect a lack of evidence-based data to support
one particular set of instructions for patients. However, we observed variability even when evidence-based guidelines exist for aspects of a bowel preparation, such as split dosing of the purgative and the importance of uninterrupted aspirin use for patients with a history of coronary artery disease [4, 6]. In 2008, the American College of Gastroenterology (ACG) adjusted its guidelines to recommend split-dose bowel preparation as one of the key measures for
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Table 1 Geographic practice variation Northeast (N = 50)
West (N = 45)
Midwest (N = 44)
South (N = 62)
Split-dose bowel preparation used exclusively
1.00 (reference)
2.27 (1.00–5.18)
0.58 (0.25–1.37)
0.81 (0.38–1.75)
Clear liquid diet advised for day before colonoscopy
1.00 (reference)
0.58 (0.09–3.66)
0.42 (0.07–2.39)
0.25 (0.05–1.19)
Continue taking aspirin
1.00 (reference)
0.23 (0.09–0.60)
0.32 (0.13–0.78)
0.32 (0.14–0.71)
Continue taking nonsteroidal anti-inflammatory drugs
1.00 (reference)
1.12 (0.26–4.78)
0.55 (0.10–3.15)
0.59 (0.13–2.74)
Management of clopidogrel included in instructions
1.00 (reference)
1.19 (0.40–3.52)
0.99 (0.35–2.83)
0.58 (0.23–1.45)
Management of warfarin included in instructions
1.00 (reference)
0.57 (0.15–2.15)
0.68 (0.17–2.70)
0.25 (0.08–0.81)
Odds ratios and 95 % CI for various aspects of bowel preparation included in patient instructions
improving quality and cost-effectiveness in colon cancer screening [4, 8]. A growing number of studies have suggested that a split-dose bowel preparation with minimally restricted diets improves the quality of bowel preparation and may increase patient satisfaction [9–12]. Our findings that 82 % of endoscopy units are recommending split-dose preparations to at least some of their patients suggests that the benefits of this regimen have been recognized by a large number of endoscopy practices. However, we found that only 42 % of units are relying on split dosing exclusively suggesting there may be barriers to implementation of the guideline. We also found that half of the units employed a MiraLAX plus Gatorade bowel preparation for some of their patients, and 18 units used this bowel preparation primarily for all of its patients. This may reflect a perceived ease of use for patients, but the literature suggests this regimen is inferior to isosmotic full- and half-dose bowel preparation regimens [13, 14]. Furthermore, the use of polyethylene glycol in this manner has not been approved by the Food and Drug Administration. Reports of severe hyponatremia and seizures associated with MiraLAX plus Gatorade have been published suggesting that further studies into safety are warranted [15]. Nonetheless, this particular regimen appears to be employed widely throughout the USA. We found that 91 % of units recommended a clear liquid diet in the 24 h preceding colonoscopy, despite a lack of evidence to support this practice. Recently, investigators have begun to examine whether such dietary restrictions are necessary [9, 16]. Randomized controlled trials have demonstrated that low-residue, or even an unrestricted diet, when coupled with a split-dose bowel preparation, resulted in similar or superior bowel cleansing compared to a clear liquid diet [9]. A less-restrictive diet may result in other improved outcomes as well, as suggested in one trial by fewer patients canceling their colonoscopy when randomized to a low-residue diet compared to a clear liquid diet (20 % versus 9 %; p = 0.03) [16]. The variability we
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observed in other dietary restrictions, such as avoidance of nuts and dairy products, indicates that more research is needed to develop evidence-based dietary instructions that optimize bowel cleanliness while maximizing patients’ dietary choices during the bowel preparation process. Medication instructions also varied across units and at times were contradictory, such as whether to continue or discontinue aspirin use. The ASGE recommends that aspirin and NSAIDs may be continued for all endoscopic procedures, although they also suggest clinicians may elect to discontinue aspirin and/or NSAIDs five to seven days before the procedure, depending on the underlying indication for anti-platelet therapy [6]. These recommendations are based on low quality evidence and this may account for the variability observed in colonoscopy instructions. Recent evidence that pacemakers and defibrillators can be implanted safely without discontinuing warfarin suggests that further studies are needed to better define the risks of colonoscopy in the setting of ongoing use of anti-platelet and anti-thrombotic agents [17]. Our findings suggest some potential ‘‘next steps’’ that could be taken to limit variability in bowel preparation. First, it appears that more rigorous dietary studies are needed to address the gaps in knowledge about exactly what foods are (or are not) associated with the adequacy of bowel preparation, and when dietary modifications should begin in the day(s) prior to the colonoscopy. Second, national gastroenterological societies could develop a standardized set of bowel instructions that include the latest evidence-based guidelines, including the appropriate use of aspirin and NSAIDs in the peri-endoscopy period. Finally, the GI Quality Improvement Consortium (GIQuIC) registry and the Digestive Health Outcomes Registry, both of which capture endoscopic data for purposes of quality improvement, could release standardized preparation instructions to their users and monitor endpoints such as bowel preparation adequacy. As relevant research findings become available, such instructions could be altered and disseminated immediately to endoscopists to be able to verify that
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improvements in preparation adequacy or other colonoscopy outcomes are indeed observed. Our study has several strengths, such as the use of a standardized protocol to collect data from a large number of geographically diverse endoscopy units. Nonetheless, we acknowledge certain limitations. We collected colonoscopy preparation instructions only from endoscopy units that participated in the ASGE EURP, so our findings may not be representative of all U.S. endoscopy units. However, as these units have been recognized for excellence in quality and safety, the variability we observed may actually underestimate the degree of variance from published guidelines across the USA. We also obtained pre-colonoscopy instructions from only half of the EURP units, but even if all non-responders provided exactly the same instructions to patients, the degree of variability in some aspects of preparation, such as management of medications, would still be substantial. Although were unable to get specific information about size, volume, and academic affiliations of the individual EURP sites from whom we obtained bowel preparation instructions, we did find that these sites were slightly different in type of unit (ASC vs. Hospital based vs. Office based) compared to the overall distribution of unit type among the entire EURP population. Therefore, our findings indicate a slight bias toward ASC practices compared to the entire EURP participating units. While it is possible hospital-based units all provide identical information to their patients, we suspect this is unlikely. We were also not able to capture the frequency with which each particular bowel purgative was prescribed, only when a particular purgative was included as a potential agent in use at each unit. We did not employ a questionnaire of endoscopy units and thus are unable to offer practice-specific information. Rather, our goal was to capture the ‘‘real world’’ experience of patients who obtain preparation instructions from a unit and then must rely on those instructions as they prepare for colonoscopy. Finally, whether the variability we observed in precolonoscopy instructions results in differences in clinically relevant patient outcomes, such as the need for repeat procedures, changes in adenoma detection rates or adverse events remains unknown. However, bowel preparations deemed inadequate for complete bowel visualization result in repeat colonoscopies either immediately or at accelerated surveillance intervals [8, 18]. Therefore, any aspect of bowel preparation that yields suboptimal results introduces patient and provider inconvenience, potentially exposes patients to otherwise unnecessary procedures, and wastes healthcare resources. When one considers that millions of colonoscopies are performed each year, the variability we documented suggests areas for quality improvement and comparative effectiveness research focused on nearly every
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aspect of pre-colonoscopy instruction, including greater diffusion of national guidelines. Conflict of interest
None.
References 1. Klabunde CN, Joseph DA, King JB, White A, Plescia M. Vital signs: colorectal cancer screening test use—United States, 2012. MMWR. 2013;62:881–888. 2. Seeff LC, Richards TB, Shaprio JA, et al. How many endoscopies are performed for colorectal cancer screening? Results from CDC’s survey of endoscopy capacity. Gastroenterology. 2004;127:1670–1677. 3. Peery AF, Dellon ES, Lund J, et al. Burden of gastrointestinal disease in the United States: 2012 update. Gastroenterology. 2012;143:1179–1187. 4. Rex DK, Johnson DA, Anderson JC, Schoenfeld PS, Burke CA, Inadomi JM. American College of Gastroenterology guidelines for colorectal cancer screening 2008. Am J Gastroenterol. 2009;104:739–750. 5. Hassan C, Bretthauer M, Kaminski MF, et al. Bowel preparation for colonoscopy: European Society of Gastrointestinal Endoscopy (ESGE) guideline. Endoscopy. 2013;45:142–150. 6. ASGE Standards of Practice Committee, Anderson MA, BenMenachem T, et al. Management of antithrombotic agents for endoscopic procedures. Gastrointest Endosc. 2009;70:1060–1070. 7. ASGE. ASGE Endoscopy Unit Recognition Program Recipients. http://www.asge.org/uploadedFiles/Clinical_Practice/Quality_ Course_-_Recognition_Program_-_GIQuic/EURP%20Honoree% 20Web%20Page%20List%201307(1).pdf. Accessed January 24, 2013. 8. Rex DK, Imperiale TF, Latinovich DR, Bratcher LL. Impact of bowel preparation on efficiency and cost of colonoscopy. Am J Gastroenterol. 2002;97:1696–1700. 9. Aoun E, Abdul-Baki H, Azar C, et al. A randomized single-blind trial of split-dose PEG-electrolyte solution without dietary restriction compared with whole dose PEG-electrolyte solution with dietary restriction for colonoscopy preparation. Gastrointest Endosc. 2005;62:213–218. 10. Abdul-Baki H, Hashash J, Elhajj I, et al. A randomized, controlled, double-blind trial of adjunct use of tegaserod in wholedose or split-dose polyethylene glycol electrolyte solution for colonoscopy preparation. Gastrointest Endosc. 2008;68:294–300. 11. El Sayed AM, Kanafani ZA, Mourad FH, et al. A randomized single-blind trial for whole versus split-dose polyethylene glycolelectrolyte solution for colonoscopy preparation. Gastrointest Endosc. 2003;58:36–40. 12. Siddiqui AA, Yang K, Spechler SJ, et al. Duration of the interval between the completion of bowel preparation and the start of colonoscopy predicts bowel-preparation quality. Gastrointest Endosc. 2009;69:700–706. 13. Enestvedt BK, Fennerty MB, Eisen GM. Randomised clinical trial: MiraLAX vs. Golytely—a controlled study of efficacy and patient tolerability in bowel preparation for colonoscopy. Aliment Pharmacol Ther. 2011;33:33–40. 14. Hjelkrem M, Stengel J, Liu M, Jones DP, Harrison SA. MiraLAX is not as effective as GoLytely in bowel cleansing before screening colonoscopies. Clin Gastroenterol Hepatol. 2011;9:326–332. 15. Nagler J, Poppers D, Turetz M. Severe hyponatremia and seizure following a polyethylene glycol-based bowel preparation for colonoscopy. J Clin Gastroenterol. 2006;40:558–559. 16. Sipe BW, Fischer M, Baluyut AR, et al. A low-residue diet improved patient satisfaction with split-dose oral sulfate solution
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1732 without impairing colonic preparation. Gastrointest Endosc. 2013;77:932–936. 17. Birnie DH, Healey JS, Wells GA, et al. Pacemaker or defibrillator surgery without interruption of anticoagulation. N Engl J Med. 2013;368:2084–2093.
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Dig Dis Sci (2014) 59:1726–1732 18. Menees SB, Kim HM, Elliott EE, Mickevicius JL, Graustein BB, Schoenfeld PS. The impact of fair colonoscopy preparation on colonoscopy use and adenoma miss rates in patients undergoing outpatient colonoscopy. Gastrointest Endosc. 2013;78:510–516.
ORIGINAL ARTICLE
Nationwide Variability of Colonoscopy Preparation Instructions Loc Ton • Helen Lee • Pushpak Taunk • Audrey H. Calderwood • Brian C. Jacobson
Received: 16 May 2014 / Accepted: 18 June 2014 / Published online: 2 July 2014 Ó Springer Science+Business Media New York 2014
Abstract Background Patients undergoing colonoscopy are typically provided preparation instructions. However, these are not standardized for type of bowel purgative, dietary restrictions, or management of prescription and nonprescription medications. Aim To examine the degree of variability in colonoscopy instructions across the USA. Methods Collected colonoscopy preparation instructions from endoscopy units that successfully participated in the American Society for Gastrointestinal Endoscopy’s Endoscopy Unit Recognition Program (EURP). Descriptive statistics were used to describe the variability in bowel preparation, dietary restrictions, medication instructions, and other patient advice. Results Preparation instructions were available from 201 (49 %) of 411 EURP units. Split dosing of bowel purgatives was used by 82 % of practices, although 79 units (39 %) offered instructions for both single- and split-dose regimens and 18 % of units relied only on single-dose regimens. Patients were restricted to a clear liquid diet on the day prior to the colonoscopy by 91 % of practices, but other specific dietary instructions (such as avoidance of nuts or legumes) varied. Instructions for the management of anti-thrombotic and anti-platelet agents, nonsteroidal anti-inflammatory drugs and diabetes medications varied widely among practices. Geographic variations in instructions were also observed. Compared to units in the northeast, units in the west were more likely to rely on split-dose
L. Ton H. Lee P. Taunk A. H. Calderwood B. C. Jacobson (&) Boston University Medical Center, 85 East Concord Street, Room 7721, Boston, MA 02118, USA e-mail: [email protected]
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preparations exclusively (p = 0.05) and units in the south were less likely to include instructions on warfarin management (p \ 0.02). Units throughout the USA were less likely to specifically recommend continuing aspirin use compared to the northeast (p \ 0.02). Conclusion Despite national recommendations for use of split-dose bowel purgatives, many practices are still relying on single-dose preparations. Clear liquid diets are widely recommended for the day prior to the colonoscopy, despite a lack of data to support the need for such a strict dietary regimen. Patients receive disparate instructions regarding the management of their medications. These findings suggest a need for more evidence-based and comprehensive colonoscopy preparation instructions. Keywords Variability Colonoscopy Endoscopy Bowel Preparation instructions Endoscopist Ambulatory surgical centers (ASC) Endoscopy Unit Recognition Program (EURP)
Introduction An estimated 11–14 million colonoscopies are performed annually in the USA for a variety of indications, and colonoscopy is now the most relied-upon means of colorectal cancer screening having been performed on more than 53 % of the screening-eligible population in every state [1–3]. Prior to the colonoscopy, patients typically receive instructions on how to prepare for their procedure, including dietary restrictions, proper use of a bowel purgative (usually 2–4 l of an isosmotic or hyperosmotic solution), and any alterations in the use of their usual medications. Current guidelines surrounding preparation for colonoscopy are scant, limited to administration of the
Dig Dis Sci (2014) 59:1726–1732
bowel purgative in a split-dose fashion (i.e., consuming half to three quarters of the purgative the day prior to the procedure and consuming the remainder the morning of the procedure) and the management of anti-platelet and antithrombotic agents [4–6]. We sought to assess the degree of variability in colonoscopy preparation instructions across the USA in order to determine the extent to which existing guidelines are being followed and to identify areas of practice variation that might benefit from further research.
Methods This study was approved by the Institutional Review Board (IRB) at Boston University Medical Center. A list of 411 endoscopy units that successfully participated in the American Society for Gastrointestinal Endoscopy’s (ASGE) Endoscopy Unit Recognition Program (EURP) was obtained from the publically available pages of the ASGE website on January 24, 2013 [7]. The EURP recognizes endoscopy units that, among other requirements, has current accreditation by a recognized accrediting body; has sent a representative to attend the ASGE’s Improving Quality and Safety in Your Endoscopy Unit course; attests that the unit has adopted ASGE and Centers for Disease Control and Prevention privileging, reprocessing and infection control guidelines; and has an ongoing quality improvement program with the measurement of several important quality measures including quality of bowel preparation during colonoscopy and patient satisfaction. The EURP is open to all settings where gastrointestinal endoscopy is performed, including office-based endoscopy units, hospital-based endoscopy units, and ambulatory surgical centers (ASCs). We conducted an internet search to identify each unit’s contact information, and to determine whether online colonoscopy preparation instructions were available from that unit’s own website. We made telephone calls to all endoscopy units that lacked a website or online instructions. After briefly explaining our study and confirming the organization’s name and location, we requested copies of their preparation instructions. If an endoscopy unit (such as an ASC) did not have instructions available at that unit, we requested the contact information of the endoscopist(s) or practice group(s) that performed procedures at that unit. When different instructions were obtained from multiple endoscopists that performed endoscopy at a single EURP unit, we treated all instructions collectively as if they were from a single unit. All calls were made during normal business hours and a maximum of two calls were made to each unit. If we were unable to obtain information after the second call, the unit was excluded from further analysis. A copy of our IRB approval letter was offered to any
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interested participants. Preparation instructions were received by either secured facsimile or e-mail. We collected information about preparation instructions in four distinct categories: bowel purgative and method of administration, dietary instructions, medication instructions, and patient safety and comfort instructions. Bowel purgative methods were categorized as single-dose (i.e., all purgative taken the day prior to, or morning of the procedure), split-dose, or a combination of the two when a unit provided both types of instructions to patients. Dietary restrictions were categorized as either a strict clear liquid diet or a more liberal diet for the day prior to the colonoscopy. Dietary instructions were categorized as having recommendations about specific food items such as nuts, seeds, gelatin, dairy, alcohol, and colored or dyed foods. We also examined the instructions for common medications, such as anti-thrombotic and anti-platelet agents (aspirin, clopidogrel and warfarin), nonsteroidal antiinflammatory drugs (NSAIDs), cardiac medications (antiarrhythmic and antihypertensive agents), diabetes medications (oral hypoglycemic agents and insulin), and iron supplements. Data on patient safety and comfort instructions included information about what to do in the event of difficulties during bowel preparation, what to wear the day of the procedure, and the need to arrange an escort home post-procedure. Descriptive statistics, including frequencies and percentages, were used. We examined the association between geographic region and specific aspects of bowel preparation to calculate odds ratios (OR) with 95 % confidence intervals (CI) using logistic regression with instructions from the northeast serving as the referent (SAS 9.1, Cary, NC).
Results We obtained online instructions from 142 EURP units and received instructions by e-mail and facsimile from an additional 59 units for a total of 201 units (49 %). The remaining 210 units lacked online preparation instructions, failed to return calls or declined to share their preparation instructions. The 201 units were geographically diverse with 45 units from the west, 44 units from the midwest, 50 units from the northeast and 62 units from the south. Among these 201 EURP units, 144 (72 %; 95 % CI 66–78 %) were ASCs, 56 (28 %; 95 % CI 49–63 %) were hospital-based units and 1 (0.5 %; 95 % CI 0–1 %) was an office-based unit. According to information from the ASGE, 59 % (95 % CI 54–64 %) of current EURP designees are ASCs, 34 % (95 % CI 30–38 %) are hospitalbased units and 7 % (95 % CI 5–10 %) are office-based units.
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Fig. 1 Frequency of bowel purgatives recommended for colonoscopy at endoscopy units
Single-dose bowel preparations were used exclusively at 37 units (18 %), split-dose preparations were used exclusively at 85 units (42 %), and both single- and split-dose preparations were used at 79 units (39 %). There was a range of purgatives prescribed, including isosmotic fulland half-volume polyethylene glycol-based preparations and hyperosmotic preparations (Fig. 1). A MiraLAX (MSD Consumer Care, Inc.) plus Gatorade (PepsiCo, Inc.) preparation was offered by 107 units (53 %), magnesium citrate with or without bisacodyl was offered by 41 units (20 %), and a phosphosoda preparation was offered by 17 units (8 %). There were 55 units (27 %) with purgative instructions that varied according to whether colonoscopy appointments were in the morning or afternoon (e.g., single-dose for morning procedures and split-dose for afternoon procedures), but only two units employed a same-day bowel preparation for afternoon procedures. A strict clear liquid diet was assigned for the day preceding colonoscopy by 183 units (91 %) while the remaining 18 units (9 %) offered more liberal diets. Many of these units also recommended against the intake of specific foods including nuts, seeds, pulp, and fiber (66 %); dairy products (84 %); alcohol (35 %); red, blue, green, and/or purple dyed foods (94 %) and gelatin (3 %). Instructions on when to begin avoidance of nuts, seeds, pulp, and fiber ranged from 1 to 10 days (median 3 days) prior to the colonoscopy. Some form of medication instructions were included in 188 units’ (94 %) instructions. Patients were asked to discontinue aspirin at 26 % of units, to continue taking aspirin at 27 % of units, and to consult with their prescribing physician about the need to continue or discontinue aspirin use at 17 % of units. The remaining 30 % of units did not include any information about aspirin use in their instructions. The majority of units recommended
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consulting the prescribing physician for help with management of clopidogrel (67 %) and warfarin (72 %). Only 50 % of units explicitly instructed patients to continue their antiarrhythmic and antihypertensive agents and 60 % of units encouraged discontinuation of iron supplementation. Figures 2 and 3 demonstrate the variability in medication instructions among these 201 endoscopy units, including significant variability in the management of oral hypoglycemic agents and insulin in the days prior to and day of colonoscopy (Fig. 3). There was significant geographic practice variation (Table 1). Compared to units in the northeast, units in the west were more likely to rely on split-dose preparations exclusively (OR 2.27, 95 % CI 1.00–5.18) and units in the south were less likely to include instructions on warfarin management (OR 0.25, 95 % CI 0.08–0.81). Units throughout the USA were less likely to specifically recommend continuing aspirin use compared to the northeast. Regarding patient safety and comfort instructions, 48 % of units provided specific contact information in the event that patients encountered problems with their bowel preparation and 22 % of units recommended products such as petroleum jelly, diaper wipes, zinc oxide cream, and topical phenylephrine creams and ointments to help with skin irritation. For the day of the colonoscopy, some units provided recommendations on appropriate attire (30 %) and information about the duration of the procedure (37 %). Nearly all units (91 %) provided clear instructions to arrange for an escort and transportation home.
Discussion This sampling of instructions from endoscopy units throughout the USA demonstrates significant variability in
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Fig. 2 Frequency of the types of medication instructions included or not included for the management of anti-thrombotic agents, anticoagulants, nonsteroidal anti-inflammatory drugs, cardiac medications, and iron supplementation
Fig. 3 Frequency of the types of medication instructions included or not included for the management of diabetic medications for the day prior to, and day of, colonoscopy
the quantity and content of information provided to patients regarding preparation for colonoscopy. We found variation in nearly every aspect of colonoscopy preparation including how to use the bowel purgative, what foods to avoid and when, how to manage other prescribed medications, and how to cope with the difficulties of the preparation. We also found an association between some aspects of bowel preparation and geographic location. In some cases, variability may reflect a lack of evidence-based data to support
one particular set of instructions for patients. However, we observed variability even when evidence-based guidelines exist for aspects of a bowel preparation, such as split dosing of the purgative and the importance of uninterrupted aspirin use for patients with a history of coronary artery disease [4, 6]. In 2008, the American College of Gastroenterology (ACG) adjusted its guidelines to recommend split-dose bowel preparation as one of the key measures for
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Table 1 Geographic practice variation Northeast (N = 50)
West (N = 45)
Midwest (N = 44)
South (N = 62)
Split-dose bowel preparation used exclusively
1.00 (reference)
2.27 (1.00–5.18)
0.58 (0.25–1.37)
0.81 (0.38–1.75)
Clear liquid diet advised for day before colonoscopy
1.00 (reference)
0.58 (0.09–3.66)
0.42 (0.07–2.39)
0.25 (0.05–1.19)
Continue taking aspirin
1.00 (reference)
0.23 (0.09–0.60)
0.32 (0.13–0.78)
0.32 (0.14–0.71)
Continue taking nonsteroidal anti-inflammatory drugs
1.00 (reference)
1.12 (0.26–4.78)
0.55 (0.10–3.15)
0.59 (0.13–2.74)
Management of clopidogrel included in instructions
1.00 (reference)
1.19 (0.40–3.52)
0.99 (0.35–2.83)
0.58 (0.23–1.45)
Management of warfarin included in instructions
1.00 (reference)
0.57 (0.15–2.15)
0.68 (0.17–2.70)
0.25 (0.08–0.81)
Odds ratios and 95 % CI for various aspects of bowel preparation included in patient instructions
improving quality and cost-effectiveness in colon cancer screening [4, 8]. A growing number of studies have suggested that a split-dose bowel preparation with minimally restricted diets improves the quality of bowel preparation and may increase patient satisfaction [9–12]. Our findings that 82 % of endoscopy units are recommending split-dose preparations to at least some of their patients suggests that the benefits of this regimen have been recognized by a large number of endoscopy practices. However, we found that only 42 % of units are relying on split dosing exclusively suggesting there may be barriers to implementation of the guideline. We also found that half of the units employed a MiraLAX plus Gatorade bowel preparation for some of their patients, and 18 units used this bowel preparation primarily for all of its patients. This may reflect a perceived ease of use for patients, but the literature suggests this regimen is inferior to isosmotic full- and half-dose bowel preparation regimens [13, 14]. Furthermore, the use of polyethylene glycol in this manner has not been approved by the Food and Drug Administration. Reports of severe hyponatremia and seizures associated with MiraLAX plus Gatorade have been published suggesting that further studies into safety are warranted [15]. Nonetheless, this particular regimen appears to be employed widely throughout the USA. We found that 91 % of units recommended a clear liquid diet in the 24 h preceding colonoscopy, despite a lack of evidence to support this practice. Recently, investigators have begun to examine whether such dietary restrictions are necessary [9, 16]. Randomized controlled trials have demonstrated that low-residue, or even an unrestricted diet, when coupled with a split-dose bowel preparation, resulted in similar or superior bowel cleansing compared to a clear liquid diet [9]. A less-restrictive diet may result in other improved outcomes as well, as suggested in one trial by fewer patients canceling their colonoscopy when randomized to a low-residue diet compared to a clear liquid diet (20 % versus 9 %; p = 0.03) [16]. The variability we
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observed in other dietary restrictions, such as avoidance of nuts and dairy products, indicates that more research is needed to develop evidence-based dietary instructions that optimize bowel cleanliness while maximizing patients’ dietary choices during the bowel preparation process. Medication instructions also varied across units and at times were contradictory, such as whether to continue or discontinue aspirin use. The ASGE recommends that aspirin and NSAIDs may be continued for all endoscopic procedures, although they also suggest clinicians may elect to discontinue aspirin and/or NSAIDs five to seven days before the procedure, depending on the underlying indication for anti-platelet therapy [6]. These recommendations are based on low quality evidence and this may account for the variability observed in colonoscopy instructions. Recent evidence that pacemakers and defibrillators can be implanted safely without discontinuing warfarin suggests that further studies are needed to better define the risks of colonoscopy in the setting of ongoing use of anti-platelet and anti-thrombotic agents [17]. Our findings suggest some potential ‘‘next steps’’ that could be taken to limit variability in bowel preparation. First, it appears that more rigorous dietary studies are needed to address the gaps in knowledge about exactly what foods are (or are not) associated with the adequacy of bowel preparation, and when dietary modifications should begin in the day(s) prior to the colonoscopy. Second, national gastroenterological societies could develop a standardized set of bowel instructions that include the latest evidence-based guidelines, including the appropriate use of aspirin and NSAIDs in the peri-endoscopy period. Finally, the GI Quality Improvement Consortium (GIQuIC) registry and the Digestive Health Outcomes Registry, both of which capture endoscopic data for purposes of quality improvement, could release standardized preparation instructions to their users and monitor endpoints such as bowel preparation adequacy. As relevant research findings become available, such instructions could be altered and disseminated immediately to endoscopists to be able to verify that
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improvements in preparation adequacy or other colonoscopy outcomes are indeed observed. Our study has several strengths, such as the use of a standardized protocol to collect data from a large number of geographically diverse endoscopy units. Nonetheless, we acknowledge certain limitations. We collected colonoscopy preparation instructions only from endoscopy units that participated in the ASGE EURP, so our findings may not be representative of all U.S. endoscopy units. However, as these units have been recognized for excellence in quality and safety, the variability we observed may actually underestimate the degree of variance from published guidelines across the USA. We also obtained pre-colonoscopy instructions from only half of the EURP units, but even if all non-responders provided exactly the same instructions to patients, the degree of variability in some aspects of preparation, such as management of medications, would still be substantial. Although were unable to get specific information about size, volume, and academic affiliations of the individual EURP sites from whom we obtained bowel preparation instructions, we did find that these sites were slightly different in type of unit (ASC vs. Hospital based vs. Office based) compared to the overall distribution of unit type among the entire EURP population. Therefore, our findings indicate a slight bias toward ASC practices compared to the entire EURP participating units. While it is possible hospital-based units all provide identical information to their patients, we suspect this is unlikely. We were also not able to capture the frequency with which each particular bowel purgative was prescribed, only when a particular purgative was included as a potential agent in use at each unit. We did not employ a questionnaire of endoscopy units and thus are unable to offer practice-specific information. Rather, our goal was to capture the ‘‘real world’’ experience of patients who obtain preparation instructions from a unit and then must rely on those instructions as they prepare for colonoscopy. Finally, whether the variability we observed in precolonoscopy instructions results in differences in clinically relevant patient outcomes, such as the need for repeat procedures, changes in adenoma detection rates or adverse events remains unknown. However, bowel preparations deemed inadequate for complete bowel visualization result in repeat colonoscopies either immediately or at accelerated surveillance intervals [8, 18]. Therefore, any aspect of bowel preparation that yields suboptimal results introduces patient and provider inconvenience, potentially exposes patients to otherwise unnecessary procedures, and wastes healthcare resources. When one considers that millions of colonoscopies are performed each year, the variability we documented suggests areas for quality improvement and comparative effectiveness research focused on nearly every
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aspect of pre-colonoscopy instruction, including greater diffusion of national guidelines. Conflict of interest
None.
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