Ethnic Inequity in the Current Approach to H. pylori Testing and Treatment: Linked Data Cohort Analysis

Background: As seen globally, there are up to sixfold differences in gastric cancer mortality by ethnicity in Aotearoa New Zealand, and H. pylori is the major modifiable risk factor. This study investigates whether current H. pylori testing and treatment approaches are equitable.

Materials and methods: The study design was a retrospective cohort analysis of linked administrative health data. Laboratory testing data and pharmacy dispensing were linked to the Northern region health user population dataset (1.9 million) from 2015 to 2018. We investigated an individual's first test for H. pylori. Regression analyses compared ethnic differences in rates of H. pylori testing, infection, treatment, and retesting, adjusted for age, sex, and calendar year.

Results: Ethnic inequities were present across the clinical pathway. Compared to sole-European, testing rates were lowest in Māori (OR 0.69) and Pacific (OR 0.81) and highest in Middle-Eastern/Latin-American/African (MELAA) (OR 2.21) and Asian (OR 2.02). Positivity rates were highest in MELAA (RR 2.96, 39%) and Pacific (RR 2.84, 38%) followed by Asian (RR 1.93, 26%) and Māori (RR 1.71, 23%). Treatment rates were similar for Asian (HR 1.05), MELAA (HR 1.03), and Māori (HR 0.98) compared to sole-European but lower in Pacific (HR 0.90). Māori and Pacific were half as likely to be retested as sole-European.

Conclusions: Despite the higher prevalence of H. pylori and gastric cancer, Māori and Pacific are relatively underserved with lower rates of testing and treatment than sole-European. Improved guidelines and the consistent application of these along with an equity-focused test and treat program are likely to be particularly beneficial for Māori and Pacific in addressing inequities.