The clinical value of “exception item” colonoscopy (MBS item 32228)

Most colonoscopies in Australia are performed in private hospitals and day procedure centres and are subsidised by the Medicare Benefits Schedule (MBS).1 In November 2019, the MBS introduced six indication‐specific colonoscopy items, as well as an “exception” item (32228) for clinically indicated colonoscopy not covered by other item numbers.2 Each item can be claimed only at specified intervals; item 32228 is available for a given patient only once. It has been suggested that item 32228, which allows clinician discretion once in a patient’s lifetime, could be removed from the schedule.

In this study, we evaluated how well the MBS items for colonoscopy are correlated with colorectal pathology. It was approved by the UnitingCare Health Human Research and Ethics Committee (2021.04.342). We reviewed all colonoscopies performed at our private practice (GastroIntestinal Endoscopy, Brisbane) during the 2020 calendar year. As part of our continuous quality improvement program, we record all colonoscopy findings and provide quality reports to each colonoscopist. Adenomas and sessile serrated lesions (SSLs) are pre‐cancerous polyps, and the adenoma detection rate (ADR) and SSL detection rate (SSLDR) for patients aged 50 years or more (excluding those with poor bowel preparation, colonic resection, or inflammatory bowel disease) are important colonoscopy quality indicators.3 The likelihood of future malignant transformation is greater for advanced adenomas and advanced serrated polyps, pathologically more progressed polyps defined by their histology and size.4 We assessed the statistical significance of differences in pathological yield between item 32222 and 32228 colonoscopies in a logistic generalised linear mixed effects model (quasi‐binomial error distribution), with colonoscopist as a random effect.5

In 2020, ten experienced colonoscopists at our practice performed 4422 colonoscopies eligible for our analysis. Ninety‐three patients underwent more than one colonoscopy during the year. As expected, the ADRs were generally greater for higher risk surveillance items (32223–32226). The proportions of colonoscopies in patients aged 50 years or more in which adenomas were removed, however, were similar for items 32228 and 32222 (diagnostic colonoscopies; 50.8% v 56.9%). The SSLDR for patients aged 50 years or more was higher for item 32228 than for item 32222 colonoscopies (38% v 27.3%; P = 0.001). In colonoscopies for patients aged 50 years or more, the rates of detection of any advanced polyp were also similar for the two items (32222: 21.5%; 32228: 20%) (Box). Fifteen colorectal cancers were identified, 14 by item 32222 colonoscopies and one by an item 32223 colonoscopy.

Colonoscopy quality is a major focus of our practice. It is possible that the pathological yield for 32228 colonoscopies is lower in practices with overall lower polyp detection rates.

Our findings suggest that about one in five “exception” colonoscopies (item 32228) detect and excise advanced pre‐cancerous polyps. Deleting item 32228 from the MBS would reduce quality of care for people.