The regional and ethnic differences in rates of publicly funded osteoarthritis (OA)-associated hip and knee replacement surgeries and mortality after surgery were explored in this New Zealand populationbased, retrospective, cross-sectional study. A total of 53,439 publicly funded primary hip replacements and 50,072 publicly funded primary knee replacements with a diagnosis of OA were identified between 2005 and 2017 in patients aged 14-99 years. Increases in the number and age-standardised rates of hip and knee replacements were seen over the time period, with Māori having the highest age-standardised rate of hip replacements, followed by European/others and Pacific peoples; Asians had the lowest rate. Pacific peoples had the highest age-standardised rate of knee replacements, followed by Māori and European/others, while Asians again had the lowest rate. The lowest rates of hip and knee surgeries were seen in the Northern Health Network and the Southern Health Network, respectively. Standardised mortality ratios decreased over the time period and were lower than in the general population: 0.92 (95% CI 0.89-0.95) for hip and 0.79 (95% CI 0.76-0.82) for knee surgery recipients. 30-day, 90-day and 1-year mortality patterns were similar to the standardised mortality ratios.
