The preprocedural evaluation of the patient prior to colonoscopy is a crucial step in maintaining high-quality colonoscopy. This may be done by the endoscopist or by the referring physician. The latter being common when patients are referred via open access systems. Criteria regarding who can, and more importantly, cannot be scheduled via open access systems should be well defined. Patients with significant medical comorbidities should most likely be evaluated by the performing endoscopist well in advance of the planned day of colonoscopy. Patients with known history of difficult examinations or suboptimal bowel preparations should be seen early as well. Although screening exams can be done anticoagulated , patients will undergo additional cost and inconvenience to return for a therapeutic procedure if polyps are detected.

The appropriateness of cancer screening should be determined, weighing risks and benefits, given patient comorbidities and age. Perioperative medication management should be reviewed with the patient. This is critical for those on anticoagulant medications. Consultation should be obtained if necessary prior to withholding anticoagulation in patients with cardiovascular stents or conditions. Informed consent must be obtained from patients. This should include common risks like bleeding or sedation complications. Risk of perforation should be discussed, and individualized if intervention is planned. Interval cancer and possibility of missed lesions should also be addressed. A target of >98% has been proposed for obtaining informed consent [4]. Ideally anything less than 100% compliance with this measure should ideally trigger a Root Cause Analysis (RCA) and evaluation of process, as this is a serious medicolegal liability.

Possibly the most important step of the preprocedure evaluation is the discussion of the bowel preparation with the patient. Bowel preparation for colonoscopy is discussed extensively in Chap. 4. However, the influence of colonic cleaning on other quality measures cannot be understated. A clean colon, devoid of stool, will allow for an efficient, high-quality examination of the colonic lumen and optimal detection of polyps. Inadequately prepped patients will require longer intubation times, possibly increasing the pressure on the endoscopist to compensate with faster withdrawals. Poor preparation may preclude intubation of the cecum. Puddles have to be cleared, and those that cannot may hide adenomatous lesions. Inadequate preparation will require patients to typically be reexamined within a year, and increases cost. Endoscopists may be less likely to feel comfortable recommending 10-year screening intervals if no adenomatous polyps are found during an examination with only marginal preparation. Stressing the importance of the preparation to patients is paramount. Written instructions should be provided. Follow-up phone calls and reminders may aid in improving compliance. Patients with history of prior poor preparation should merit special consideration and planning for extended preps, although data guiding this is limited. Increasingly, split dosing preparation regimens are being employed to improve the quality of cleansing. Patient satisfaction and compliance with these regimens remains high, even for those with early procedure times who are required to awake early to complete the second dosing schedule. Same-day preparation, adhering to American Society of Anesthesiology guidelines allowing clear liquids up to 2 h prior to sedation, may be another strategy to improve success.

The plan for sedation during the procedure should be decided upon during preprocedure evaluation. Adequate patient sedation facilitates completion of the procedure and provides a level of comfort for the patient. The endoscopist must decide if sedation will be administered by the provider or an anesthesia specialist. This is an important topic in today’s healthcare economic discussion. Sedation from an anesthesiologist or certified registered nurse anesthetist clearly increases the overall cost of the procedure. However, having a provider skilled in sedation and airway management enables the endoscopist to focus primarily on the technical performance of the colonoscopy itself and allows for expert rescue if airway trouble arises. This may allow for overall improvement in the quality of the colonoscopic examination.

The indication for colonoscopy must be appropriate and well documented. Chapter 10 discusses in detail the current guidelines for colonoscopy and appropriate intervals for reexamination. Recommendation for adherence to published guidelines for the appropriate indication for colonoscopy has been recommended to be >80% [4]. It is likely in the future that this area will be closely monitored by payers (refer to section on “Reporting and Payment Policy”). Nonindicated colonoscopy is a cause of increased cost in the healthcare system. Documentation of the clinical decision-making process is crucial when the endoscopist feels examination is warranted but falls outside published guidelines. Guidelines should never supplant individual physician decision making for specific clinical situations, but, increasingly, supporting documentation must be done.

Also recommended is adherence to published guidelines for intervals between screening exams for average-risk patients, postcancer surveillance, and for surveillance in patients with history of polyps. Previous colonoscopy date and histology of polyps, if known, should be documented. Recommended compliance is ≥90% [4]. Again, this is an area that will be closely monitored in the future.

Surveillance colonoscopy for patients with ulcerative colitis or chronic Crohn’s colitis is another area with suggested quality indicators. Surveillance examinations for colitis patients are done outside of exams necessary for changes in clinical condition, like bleeding or worsening symptoms when treatment changes may be indicated. Current American Society for Gastrointestinal Endoscopy (ASGE) guidelines recommend starting surveillance after 8 years of ulcerative colitis (exclusive of limited proctitis) or Crohn’s colitis involving more than a third of the colon [5]. Intervals of 1–3 years are recommended, with patients having primary sclerosing cholangitis and severe inflammation being at increased risk of malignancy. Recommended performance target for appropriate screening intervals in colitis is ≥90% [4].

High-quality colonoscopy mandates complete examination of the colon. By definition, this requires advancement of the tip of the colonoscope to the caput of the cecum. The ileoceal valve is the most reliable landmark of cecal intubation. It is critical to examine the portion of the cecum that lies immediately medially and behind the valve. This is a critical region where pathology can be missed. The appendiceal orifice at the convergence of the teniae coli is another important landmark. The terminal ileum can be intubated to ensure the cecum has been reached. Ileal mucosa is distinct from colonic with prominent villi. Transillumination and palpation in the right lower quadrant are unreliable predictors of cecal intubation and are not recommended. Photographic images of important landmarks documenting cecal intubation should be recorded in the endoscopy record. This is important both from a quality assurance standpoint but also from a medicolegal one. Still images may be equivocal at times. Video capture is typically not feasible for all examinations but can be useful for targeted review. Reductions in the cost of digital archiving may make this a more attractive method of CQI in the future.

Cecal intubation rates for patients undergoing routine screening examinations should exceed 95% [4]. Cases aborted due to inadequate bowel preparation or severe colitis, where there is concern for perforation, can be excluded from the denominator. Supportive photo documentation is important in these situations. Cases with a newly identified stricture or malignancy that is not traversed are typically counted. Therapeutic procedures for stricture are not. Another proposed metric for provider cecal intubation rate is ≥90% when all indications are considered [4].

Typically during proximal advancement of the colonoscope , the endoscopist is focused on reaching the cecum or ileum if that is the planned extent. Withdrawal of the scope is usually when the mucosal surface is closely examined and inspected for polyps or lesions. Methodical examination, clearing puddles, and looking behind haustral folds are intuitively necessary for the detection of polyps. Initial recommendations for withdrawal time were 6–10 min [2]. This was based on evidence showing polyp detection rate was positively correlated with longer withdrawal times. This correlation is strongest for smaller polyps [6]. The ASGE continues to recommend withdrawal times of ≥6 min in its most recent guidelines, and that measurement is documented in >98% [4]. Withdrawal time should be calculated beginning when the cecal caput is intubated and the endoscopist begins to evaluate the colonic mucosa, and ending at scope removal from the anus. This time is independent from any time spent taking biopsies or performing polypectomy.

Withdrawal times should be documented during the procedure and recorded. This process measure is relativity easy to collect and utilize as a benchmark for CQI. It should be noted that this measure is relatively easier for a provider to manipulate (waiting in the rectum until 6 min is reached). Increasing withdrawal times for endoscopist with high adenoma detection rates is unlikely to be an effective intervention but can be useful for those with lower rates. The technique and thoroughness of mucosal examination during withdrawal is likely more important than simply the duration [7]. While this metric may not be entirely valid in those patients who have previously undergone resection, it is still worth noting that it may be tracked.

Detection and removal of precancerous polyps is the goal of screening colonoscopy. This was initially supported by retrospective studies showing lower rates of colorectal cancer in those patients having polyps removed. More recently, strong evidence of the effectiveness of polyp removal on reducing CRC rates has been published [8]. Adenoma detection rate (ADR) for a provider is defined as the number of patients having at least one adenomatous polyp removed divided by the number of screening examinations . Sessile serrated and hyperplastic lesions are not counted. Tandem colonoscopy studies and studies involving CT colonography have shown that the polyp miss rate during colonoscopy can be distressingly high. This is even true for larger, more advanced adenomas. Patients who have missed adenomas are not moved to shorter surveillance intervals and are at increased risk for development of interval CRC. Fear of missed adenomas and interval cancer is a primary reason why endoscopists recommend nonstandard screening intervals. This increases the financial burden on the healthcare system. High-quality colonoscopy screening programs with high ADR providers will allow for detection of patients who require short intervals and prevent unnecessary examinations in those who do not.

ADR is an important quality metric for colonoscopy. ADR will vary based on the patient population of the endoscopist. Initial recommendations were for ADR rates to be ≥25% for a male screening population, and ≥15% for a female one [2, 3], and were set below what was known to be the actual incidence of adenomatous polyps. These have been recently increased to ≥30% male and ≥20% female [4], for reasons discussed later. A provider with a balanced cohort of screening patients would be expected to have an ADR of ≥25% overall.

More recently, ADR has been shown to have a dramatic impact on patient’s risk of developing interval colorectal cancer . In a study of over 250,000 colonoscopies with 712 interval colorectal cancers, examination by a high ADR provider was inversely correlated with development of interval cancer or cancer death [8]. ADR rates of the endoscopists in the study ranged from 7.4 to 54%. With the lowest ADR quintile as reference (ADR 7.35–19.05%), having colonoscopy by an endoscopist in the highest quintile (ADR: 33.51–52.51%) conferred essentially a 50% reduction in the risk of interval CRC (HR 0.52, 0.39–0.69, 95% CI). Each 1% increase in ADR reduced the risk of interval cancer by 3%. This evidence was cited by the ASGE in raising the performance target for ADR in the most recent guideline iteration.

Based on supporting evidence, ADR is now primarily considered an outcome measure, rather than a measure of process of care. ADR can be more labor intensive to track than other quality indicators. Accurate measurement of ADR requires follow-up reporting of pathology results. In the future, this may be more easily done by integration of electronic endoscopy and pathology reporting systems. However, currently this remains a manual process for the most part.