Background
Fairness in access to health care is one of the founding principles of the NHS, yet there is some evidence for the inverse care law which states that those with the greatest need are often the least likely to access care. Here we look at the relationship between the rate of NHS hip replacement operations, as a proxy for access to elective care, and deprivation in England.
The chart shows the directly standardised rate of hip replacement operations per 100,000 population, adjusted for sex and age, by Index of Multiple Deprivation (IMD) decile in 2022/23. The most deprived decile had the lowest surgery rate, with 161 hip replacements per 100,000 population. The highest surgery rate was found in decile 6, with 204 hip replacements per 100,000 population. Research has shown that there is a higher prevalence of joint problems in more deprived areas – for example higher rates of GP consultation for osteoarthritis (the most common reason for needing a hip replacement). The lower rates of procedures in the more deprived areas could represent some unmet need (and an example of the ‘inverse care law’).
It should be noted that population estimates for 2020 were used to compute the rate for 2022/23, which may lead to a slight overestimation in hip replacement rates as the population has increased over time..
Between 2008/09 and 2019/20, the rate of hip replacement operations increased in the least deprived areas but decreased in the most deprived areas. Rates of hip replacement decreased by 9 per 100,000 population in the most deprived decile but increased by 12 per 100,000 population in the least deprived decile (the largest increase of all deciles).
In 2020/21, the rate of hip replacement operations plummeted by more than 50% for all groups. Due to the onset of the Covid-19 pandemic in March 2020, non-urgent elective care was postponed in order to allocate more resources towards managing inpatient and critical care capacity. For individuals living in the most deprived areas, the rate was 58% lower than it was in the previous year. For individuals living in the least deprived area, the rate was 54% lower. The ratio of inequality (rate in most deprived decile ÷ rate in least deprived decile; the higher the number and closer it is to 1.0 = better equity) was 0.73 in 2020/21, the lowest it has been since 2008/09.
Since 2020/21, operations have picked up again, but not to pre-pandemic levels. In 2022/23, the rate of hip replacement operations for the most deprived was 161 per 100,000, while that for the least deprived was 186 per 100,000 population. However, given that population estimates for 2020 were used to compute the rate for 2021/22 and 2022/23, it may lead to a slight overestimation in hip replacement rates as the population has increased over time.
About this data
These indicators use data from Hospital Episode Statistics (HES) and the Office for National Statistics (ONS).
The directly standardised rate of NHS hip replacement operations per 100,000 population aged 18+ years is a fraction calculated as follows: the numerator is the number of hip replacement operations of adults aged 18+ years where the main operation code is between W37-W39 or W93-W95. The denominator is the mid-year population estimates by age and sex at Lower Layer Super Output Area (LSOA) in England.
The Index of Multiple Deprivation was used to quantify levels of deprivation. Between 2008/09 and 2016/17, the 2015 deprivation deciles were used. Data from 2017/18 onwards uses the 2019 deprivation deciles. The difference in classification of deciles may result in different individuals falling under the highest and lowest deprivation category.
Mid-year population rates were used to calculate the rates for 2021/22 and 2022/23. This is because the population estimates for those years use the new 2021 LSOAs while HES data still uses the old LSOAs. This will be corrected when the new 2021 LSOAs are implemented in HES data.