Elsevier

Digestive and Liver Disease

Volume 45, Issue 12, December 2013, Pages 1022-1027
Digestive and Liver Disease

Digestive Endoscopy
Inter-centre variability of the adenoma detection rate: A prospective, multicentre study

https://doi.org/10.1016/j.dld.2013.05.009Get rights and content

Abstract

Background

Suboptimal colonoscopy quality is related to a higher risk of interval cancer. Aim of our study was to explore the variability in detection rate of neoplasia among different endoscopic centres in an unselected population.

Methods

Consecutive patients referred for colonoscopy in 28 Italian centres were included. Detection rate for polyp, neoplasia and advanced neoplasia was assessed at both the individual and centre level. Inter-centre variability in detection rate of colorectal lesions was explored after adjusting for patient-related factors at multivariate analysis.

Results

3150 patients were included. Median detection rates for polyp, neoplasia and advanced neoplasia were 35%, 26% and 13%. At multivariate analysis, patient-related factors associated with neoplasia detection were age, sex, alcohol and smoking history. After adjusting for these variables, a statistically significant difference in the observed/expected ratio among different centres was observed (Chi-squared test: p < 0.01). Among non-patient-related factors, documentation of withdrawal time was associated with neoplasia detection. However, a statistically significant inter-centre variability also remained after adjusting for this variable.

Conclusions

A wide variability was present in the detection rate of neoplasia and advanced neoplasia at the level of endoscopic centres in an unselected population. The adoption of a centre-related neoplasia detection rate could be suggested as a performance indicator.

Introduction

Colorectal cancer (CRC) is a major cause of morbidity and mortality [1]. Colonoscopy is highly effective in detecting advanced neoplasia, and CRC prevention by endoscopic polypectomy reduces disease-specific incidence and mortality [2]. As such, its use as a preferred screening and diagnostic strategy is supported by official guidelines [3].

The long-term efficacy of colonoscopy in preventing CRC incidence and/or mortality has been addressed in cohort and case-control studies [2], [4], [5], [6], [7], [8], [9]. Although the majority of these studies showed a very high CRC prevention rate [2], [4], [5], [6], [7], some studies showed a suboptimal CRC protection rate [8], [9], [10]. This appeared to be related to an unexpectedly high risk of post-colonoscopy CRC in the early years after colonoscopy. In a large administrative cohort of patients with negative colonoscopy, the CRC prevention rate appeared to be markedly higher when assessed 10 years after colonoscopy rather than after 5 years – i.e. 72% vs. 41% – because of the unexpected occurrence of interval cancer in the early years following colonoscopy [9]. In a large case-control study, Baxter et al. showed a substantially lower CRC mortality prevention rate in the first 2 years following colonoscopy compared with the following period [8]. The higher risk of post-colonoscopy CRC also appeared to be better represented in the proximal than in the distal colon [9], [11], [12].

The quality of colonoscopy has been strictly related to the risk of post-colonoscopy CRC [13]. In large administrative cohort or case-control studies, the risk of interval cancer – including its proximal localization – appeared to be independently predicted by a relatively low rate of polyp/adenoma detection [12], [14], [15], [16]. It was similarly lower when the adenoma/polyp detection rates of the selected endoscopist were ranked as moderate to high [14], [15], [16], [17].

Only a few studies addressed the variability of the polyp/adenoma detection rate within the endoscopic community. Although these studies usually showed a high degree of variability in the polyp/adenoma detection rate with a wide range of 10–40% among different endoscopists, whether there is also inter-centre variability in the adenoma detection rate is still controversial [18], [19]. This may be relevant when considering that an endoscopic centre usually has two or more endoscopists, which are simpler to monitor than a single endoscopist.

Although in Italy the National Health System is running a screening programme with immunochemical faecal testing, no systematic approach to monitoring or improving colonoscopy quality has yet been implemented. Moreover, although nurses are not yet allowed to perform colonoscopy, all physicians are, irrespectively of their specialty. This would appear to be an ideal scenario for assessing whether any intervention would really be needed.

The aim of our prospective, multicentre study was to measure the inter-centre variability in the adenoma detection rate in a large unselected endoscopic population, and whether such variability was explained by patient- or endoscopist-related variables.

Section snippets

Materials and methods

A prospective, multicentre study involving 28 open-access Endoscopy Units, uniformly distributed throughout Italy, was performed between March and October 2010. According to the protocol, all patients referred to the participating centres for routine colonoscopy over 1 month were prospectively enrolled. Patients were excluded only when referred for emergency colonoscopy. Colonoscopies were performed according to predefined weekly schedules, the referring physicians being unaware of the purpose

Study population

A cohort of 3150 (males: 52%; mean age: 60 years, range 19–95 years) patients were included in the 28 centres. The median number of patients included in each centre was 100 (range: 48–281). A positive family history was present in 604 patients (19%). BMI was <25 in 1386 (44%), and was ≥25 in the remaining cases. A history of smoking or alcohol consumption was reported by 1050 (33%) and 1087 (35%) patients respectively. The clinical indication for colonoscopy was an alarm symptom or sign in 944

Discussion

According to our study, there is a substantial variability in the detection rate of both neoplasia and advanced neoplasia among different endoscopic centres. The detection rate of colorectal lesions depends not only on endoscopist performance, it is also affected by the prevalence rate of neoplastic lesions. For this reason, we adjusted the expected prevalence of colorectal lesions for each centre, according to the patient-related factors identified by the logistic regression model in our study

Conflict of interest

None declared.

References (28)

  • M.S. Sawhney et al.

    Effect of institution-wide policy of colonoscopy withdrawal time ≤7 minutes on polyp detection

    Gastroenterology

    (2008)
  • D.A. Corley et al.

    Can we improve adenoma detection rates? A systematic review of intervention studies

    Gastrointestinal Endoscopy

    (2011)
  • D.K. Rex et al.

    Accuracy of pathologic interpretation of colorectal polyps by general pathologists in community practice

    Gastrointestinal Endoscopy

    (1999)
  • B.K. Edwards et al.

    Annual report to the nation on the status of cancer, 1975–2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates

    Cancer

    (2010)
  • Cited by (16)

    • An Italian prospective multicenter study on colonoscopy practice and quality: What has changed in the last 10 years

      2023, Digestive and Liver Disease
      Citation Excerpt :

      In two meta-analyses, split-dose bowel preparations and same-day preparations were reported to improve bowel preparation outcomes [21,22]. Herein, adequate bowel preparation (BBPS ≥6) was reported in 95.6% of cases, with a 22% increase compared to the 78% reported 10 years ago [17]. The current percentage of adequate bowel cleansing was above the recommended ESGE/ASGE-ACG threshold.

    • Adenoma detection rate and risk of colorectal cancer

      2017, Best Practice and Research: Clinical Gastroenterology
      Citation Excerpt :

      Indeed, endoscopist has been shown to be the most powerful predictor of ADR [17]. The studies using primary colonoscopy screening show that ADR ranges between 7% and 44% [5,17–23] with some studies reporting ADR of more than 50% [24,25]. At the same time, polyp miss rate estimated based on tandem colonoscopies varies between 2.1% for adenomas ≥10 mm and 26% for adenomas 1–5 mm [26].

    • Trends in adenoma detection rates during the first 10 years of the German screening colonoscopy program

      2015, Gastroenterology
      Citation Excerpt :

      Limitations include the restriction of presentation to average ADRs. Both absolute levels of ADR and their trends show substantial variation between individual colonoscopists.9,15,32 This also applies to Germany,33 but variation and ranking of sex- and age-adjusted ADR across colonoscopists was rather stable over time during the 5-year period from 2008 to 2012 for which this information was available.

    • One or two operator technique and quality performance of colonoscopy: A randomised controlled trial

      2014, Digestive and Liver Disease
      Citation Excerpt :

      Despite the 1OP technique is recommended by professional societies and represents standard practice in the United States [6], the other option is still commonly adopted in some European and Eastern Countries [7–9]. In a recent Italian colonoscopy survey [10], about half of the procedures were performed with the assistance of the nurse to hold the scope. Data from GastroNet quality assurance program in Norway reported that 2OP technique was practiced by about 20% of endoscopists.

    View all citing articles on Scopus
    1

    On behalf of the Quality SIED Group. See Appendix A.

    View full text