Validation of Australian and Victorian guidelines for colonoscopy triage.

BACKGROUND AND AIMS: This study aimed to assess the diagnostic performance of National and Victorian colonoscopy triage guidelines and potential redistribution of triage categories. METHODS: Diagnostic validation study comparing colonoscopy triage guidelines against a reference colonoscopy dataset. PARTICIPANTS: reference dataset of 2,378 colonoscopies from 1 October 2014 to 30 June 2016. Comparison with triage categorisation determined using: National Cancer Council Australia guidelines; Victorian triage guidelines; Optimal Cancer Care Pathways recommendations. MAIN OUTCOME MEASURES: i. Proportion of colonoscopies assigned to each triage category; ii. detection rate (proportion of cancers assigned to triage Category 1); iii. conversion rate (proportion of triage Category 1 colonoscopies which diagnose a cancer). RESULTS: After adjusting for data absent in referrals, the National and Victorian guidelines reduced the proportion of Category 1 colonoscopies compared with the reference triage (National 76.3% vs 58.6%; 95% CI for difference 15.0 - 20.3% p<0.0001. Victorian 76.3% vs 66.3%; 95% CI for difference 7.4 - 12.6% p<0.0001). Victorian guidelines were associated with the highest detection rate (91.4%) and a conversion rate of 5.4% although the number of cancers limited the power to detect significant differences on these metrics. There was a higher proportion of unclassifiable colonoscopies using the National guidelines than the Victorian ones due to their focus on symptomatic indications. CONCLUSIONS: The Victorian guidelines could reduce the proportion of Category 1 colonoscopies by 10% without reducing conversion or detection rates. This would require improvements in the quality of referrals and ordering faecal occult blood tests in 6% of symptomatic patients. This article is protected by copyright. All rights reserved.