Hip arthroplasty practice across the Organisation for Economic Co-operation and Development (OECD) over the last decade

Introduction There are large variations in the number of hip replacements performed between countries, demonstrating large health inequalities; however, there has been limited research on this variation. The aims of this paper were to compare rates of hip replacements using Organisation for Economic Co-operation and Development (OECD) data for the period 2008-2018. The study also compared changes in the number of hip replacements in the total population and in only those aged over 65, and looked for a correlation of health expenditure and gross domestic product (GDP) with rates of hip replacements.Methods The OECD collects annual data from all member countries on the numbers of hip replacements, healthcare expenditure and GDP. Data analysis was undertaken using STATA. Descriptive statistics and Pearson's correlation coefficient were performed.Results The mean number of hip replacements performed in OECD countries in 2018 was 191.5 per 100,000 population per year. The largest number was 310.6 in Germany and the lowest was 8.6 in Mexico. There has been a 21.7% increase in the mean number of hip replacements across OECD countries. There was a moderate and significant Pearson coefficient of 0.468 (p = 0.009) between the number of hip replacements performed per 100,000 population in 2018 and GDP per person, and a strong and significant correlation with health expenditure (R = 0.784, p < 0.001). There was a moderate correlation (R = 0.645, p = 0.003) between the percentage change in the number of hip replacements performed per 100,000 population and the percentage change in healthcare expenditure per person between 2008 and 2018.Conclusions There is 36-fold variation in the practice of hip replacements across the OECD and the number of hip replacements has increased by more than 20% over the past decade. The number of hip replacements performed appears to be correlated with health expenditure in each country and may indicate a need that can only be met by increasing health expenditure.