Equity of colonoscopy provision and quality in Māori and New Zealand Europeans: a comparative retrospective study

High-quality colonoscopy is essential for investigating suspected colorectal cancer and relies on endoscopists meeting key performance indicator (KPI) targets. The rising demand for colonoscopy raises concerns that Māori populations could be under-served. This study aimed to compare rates of colonoscopy provision and colonoscopy KPIs between Māori and New Zealand (NZ) European patients.

This retrospective comparative study was conducted at Whanganui Hospital (NZ). Consecutive colonoscopies performed between September 2016 and March 2020 were included. Primary outcome was the rate of colonoscopy provision for the population. Secondary outcomes were the colonoscopy completion rate (CCR), colonoscope withdrawal time (CWT), polyp detection rate (PDR) and adenoma detection rate (ADR). Subgroup analysis of ADR in index symptomatic colonoscopies was also performed.

A total of 2962 colonoscopies were analysed (385 Māori; 2577 NZ European). Rates of colonoscopy provision in participants aged ≥40 were significantly lower among Māori (6.1% versus 9.1%; P < 0.0001). The CCR (P = 1.00), CWT (P = 0.28) and PDR (P = 0.24) were similar. Whilst the ADR in the overall cohort was significantly lower in Māori (32.7% versus 40.0%; P = 0.028), this was not observed when stratified by 10-year age cohorts. The ADR was similar on subgroup analysis of index symptomatic colonoscopies (P = 0.42).

This study found inequities in access to colonoscopy services for Māori compared to NZ European patients. Among those that did receive colonoscopy, there were no differences in colonoscopy quality after age stratification. Improving equity will require the addition of colonoscopy provision rates to other mandatory KPIs and reporting these by ethnicity in all endoscopy units.