Ethnic inequality in non-steroidal anti-inflammatory drug-associated harm in New Zealand: A national population-based cohort study.

Purpose: Non-steroidal anti-inflammatory drugs (NSAIDs) are associated with many serious complications and they are widely used in New Zealand (NZ). However, differences in NSAID-associated risk for these complications between ethnic groups are largely unknown. We assessed ethnic disparities in risk of hospital admission for upper gastrointestinal bleeding (UGIB), heart failure, and acute kidney failure (AKF) in NZ's primary care population prescribed and dispensed NSAIDs.

Methods: Retrospective cohort study utilising national pharmaceutical dispensing and hospital admissions data 2007 to 2015. Patient follow-up included 90-day periods following the dispensing of NSAIDs. Risk for each adverse outcome in Maori, Pacific, European, and Asian patients was estimated using multivariable Poisson regression adjusting for age, sex, deprivation, comorbidity and concurrent drug use.

Results: 3 023 067 patients were dispensed NSAIDs between 2008 and 2015. Their total intended duration of NSAID treatment encompassed 2 353 140 patient-years. Maori, Pacific and Asian patients were younger than European patients (all P < .001). After adjusting for other risk factors, Maori (rate ratio: 2.54, 95% confidence interval: 2.23-2.90) and Pacific patients (3.17, 2.69-3.74) were more likely to be hospitalised for UGIB than Europeans (reference), and heart failure (Maori: 2.48, 2.24-2.74; Pacific: 1.97, 1.69-2.30). Risk of AKF was higher in Maori (1.46, 1.23-1.74). Higher risk for UGIB and HF in Maori and Pacific patients was most pronounced in males and patients aged <60 years.

Conclusions: Inequalities exist in the incidence of serious adverse outcomes experienced by different ethnic groups in NZ while using NSAIDs. Interventions to promote safer use of these medicines are required to reduce this inequity.