Deciding how urgently a colonoscopy is needed: the NSW categorisation guide

Demand for colonoscopy in the New South Wales public system exceeds the capacity to do it. That makes the order in which people are seen a clinical question rather than an administrative one, and getting it wrong has consequences in both directions: a person with a cancer waiting behind a queue of low-risk surveillance or a healthy person scoped early for no benefit.

The NSW colonoscopy categorisation clinical practice guide, published by the Agency for Clinical Innovation's Gastroenterology Network in August 2020, sets out how referrals should be sorted. Every patient is placed in one of three categories: category 1 for a procedure within 30 days, category 2 within 90 days and category 3 within 365 days for surveillance. The guide then lists, indication by indication, which category each presentation belongs in, so the decision is the same in Blacktown as it is in Lismore.

A/Prof Kariyawasam, then a gastroenterologist at Blacktown and Mount Druitt Hospitals, was a member of the Colonoscopy Categorisation Working Group that produced it. He is now clinical co-chair of the Agency for Clinical Innovation's Gastroenterology Network, which carries this guide among its areas of work.

What it means in practice

The categories are the reason some referrals move quickly. A positive bowel screening test, rectal bleeding in an older patient, unexplained iron deficiency and suspected inflammatory bowel disease sit high in the order. Routine surveillance after previous polyps sits lower, which is appropriate when the interval is measured in years and is the reason a surveillance colonoscopy can be scheduled well ahead rather than squeezed in.

The same logic runs through this practice. Referral categories, and what to include so a referral can be categorised properly, are set out on the page for referring doctors.

A separate question: how often, rather than how soon

Urgency is one thing and the interval between colonoscopies is another. The intervals come from the national Clinical Practice Guidelines for Surveillance Colonoscopy, which A/Prof Kariyawasam also worked on. There is a separate note on that work.

The guide, on the ACI Gastroenterology Network site