Quality in gastrointestinal endoscopy

Endoscopy is a powerful and pivotal tool in the diagnosis and management of gastrointestinal pathology. Ensuring that endoscopy is of high quality is fundamental to providing the best care and experience for our patients. High quality endoscopy delivers better health outcomes, better patient experience, and fewer repeat procedures. Although intuitive, it is only in recent years that the evidence base to support the value of quality has grown, primarily in colonoscopy. Clear evidence exists for the role of detection and removal of polyps in preventing colorectal cancer (CRC) [1–3], and we know that patients endoscoped by clinicians with poorer adenoma detection rates (ADR) have poorer outcomes and higher rates of postcolonoscopy CRC [4,5]. A further study using polypectomy rate as a surrogate marker for ADR reached the same conclusion [6], and additional studies have shown a correlation between postcolonoscopy CRC rates and other markers of quality such as failed cecal intubation [6,7]. The quality of endoscopy being delivered in endoscopy units is known to vary considerably. Globally, back-to-back colonoscopy studies have demonstrated that 22% of all adenomas are missed [8]. In addition, studies have shown a 3–6fold variation in ADR between endoscopists [9, 10], with a 10-fold range in the mean number of adenomas detected in one study–put another way, the lowest detector missed 90% of adenomas. There is also wide variation in detection rates of serrated polyps (7–18-fold) between endoscopists [11,12]; these polyps may be an important precursor of CRC, and detecting them may be important in reducing the incidence of proximal cancer. Even when polyps are found, removal may be incomplete: the recent CARE study demonstrated that 10% of nonpedunculated polyps of 5–20mm and 23% of nonpedunculated polyps of 15–20mmwere not fully resected [13]. These gaps in quality are clinically significant: the majority of postcolonoscopy CRCs arise from missed adenomas, cancers, or incomplete polypectomies [14], and shortcomings in right-sided diagnostic rates may explain the relative failure of colonoscopy to protect against proximal CRC in many studies [15,16]. In the upper gastrointestinal tract, missed gastric cancer rates are an important measure of quality, albeit a relatively insensitive measure. In one series, 7.2% of patients with gastric cancer did not have the lesion detected at endoscopy performed within the previous year. Of these missed lesions, almost three-quarters were judged to be due to endoscopist error [17]. An Australian study also reported that although upper gastrointestinal malignancies were relatively rare after a normal esophagogastroduodenoscopy within the preceding 3 years, often an abnormality was detected but not recognized as potentially malignant by the endoscopist [18]. Additional quality measures within upper gastrointestinal endoscopy are more limited. The American Society for Gastrointestinal Endoscopy and American College of Gastroenterology task force developed 16 quality indicators for upper gastrointestinal endoscopy involving pre-, intra-, and postprocedural indicators [19–21]. Only 5 of these 16 quality indicators, however, had robust evidence to support a clear benefit with their use. The Canadian Association of Gastroenterology has developed a similar set of quality indicators for all gastrointestinal endoscopy [22]. In endoscopic retrograde cholangiopancreatography, which is one of the most complex and highest risk procedures performed regularly in endoscopy practice, there is evidence of wide variation in both completion and complication rates [23]. Quality measures and reporting of these measures are variable and some success has been achieved with database reporting [24]. Quality markers within small-bowel and capsule endoscopy are not yet clearly established.