Person or place? Finding out more about what drives health inequalities

It is known that life expectancy is higher in some areas of the UK than in others. These inequalities in health are linked to the socio-demographics of the area: poorer health and shorter life expectancy tends to be a feature of less affluent areas of the country. In this blog, the third in a series on cancer and social inequality, Fiona Ingleby discusses research which uses data from cancer patients included in the ONS Longitudinal Study to assess the evidence on health inequalities and cancer outcomes.

The NHS has set out a plan for healthcare over the next decade that specifically aims to reduce inequalities. The research that this plan is based on uses area-level statistics. In other words, the UK is split into small areas about the size of a single postcode, and each area is given a score according to a variety of measures, such as how many people in the area are unemployed or on income benefits. These scores are used to identify the more deprived areas of the country that might be in greater need of healthcare resources.

This system is convenient and widely used, but by design it is a simplification of reality. Actually, communities tend to be a mix of people from all types of occupations, educational levels and income groups. So, what does the NHS’ plan mean for people who, for example, are unemployed or on a low income, but live in an area that is scored as being quite affluent overall? Will these people be overlooked by healthcare policy that is focussed only on less affluent areas? Or do these people experience health benefits from the overall affluence of the area they live in?

We set out to explore these questions in the context of cancer. Cancer is a major health issue in the UK, with a large proportion of NHS resources dedicated towards it. Around 350 people die of cancer every day in the UK. Strikingly, it has been estimated that as many as 1 in 10 cancer deaths in the first 5 years following diagnosis are due to health inequalities.

Our study used data from cancer patients included in the ONS Longitudinal Study to assess whether there is evidence for health inequalities in terms of cancer outcomes. We used census data to group patients according to their individual circumstances, including their type of occupation, the qualifications they held, and their estimated income. We used statistical models to determine if there were differences in cancer outcomes across these occupation, education, and income groups. Our analysis therefore considered health inequalities in terms of differences among individual circumstances, as well as using the type of area they live in.

The results revealed that there are inequalities in cancer survival across different individual circumstances, in addition to the well-known inequalities across different areas. For example, women on low incomes tended to have lower survival from breast cancer than women on high incomes. In addition, for both men and women with colorectal cancer, people without many qualifications tended to experience poorer outcomes than those with a higher level of qualifications.

We expected to find that inequalities in cancer outcomes would be larger when estimated at an individual level than when estimated based on area-level scores. This is because area-level scores are a sort of average across all the people within each area. Because of this, we thought that area-level scores might only show a diluted measure of the real, underlying inequality. But we didn’t find this. In fact, inequalities were of a similar size when estimated at an individual-level and at an area-level. This suggests that a person’s individual circumstances are just as important as the overall affluence of the area they live in. It is likely that both approaches, individual- and area-level, are useful and might highlight different types of inequality, rather than one approach being more accurate than the other.

We also used our statistical models to address the question of whether the health inequalities we found across individual-level circumstances were the same across more and less affluent areas of the country. Is the experience of a cancer patient on a low income living in an affluent area the same as a cancer patient on the same income but living in a relatively poor area?

We found that the answer to this question depended on the type of cancer. For colorectal cancer, for instance, the answer was simply that differences across individual circumstances were the same, no matter where someone lived.

On the other hand, for breast and prostate cancers, inequalities between people with different types of occupation were much bigger in the poorest areas, and much smaller in the most affluent areas: a kind of amplification of inequalities in poorer areas. This means there is a sub-group of individuals who are both individually deprived and live in a poor area who experience the poorest cancer outcomes by quite some margin. These people may benefit somewhat from existing efforts to allocate NHS resources to areas of the country in greatest need. However, it’s likely that even with such policies in place, these cancer patients will still be at a disadvantage compared to more affluent individuals within their community. Additional healthcare policies that focus on individual-level inequalities could be used to target all possible sources of health inequalities.

This kind of innovative approach to healthcare policy could help to reduce inequalities more effectively. Of course, individualised health policies are often more complicated and expensive to carry out than broader, area-level approaches. Our research helps to pinpoint specific types of cancer and types of inequality that could be targeted in order to make policies more cost effective. Future research of this kind, using individual-level resources like the ONS-LS, will help to identify specific policies that could help to reduce inequalities in health overall.

The project team at the Inequalities in Cancer Outcomes Network are Fiona Ingleby, Aurelien Belot, and Laura Woods from the London School of Hygiene and Tropical Medicine, Iain Atherton from Edinburgh Napier University, Lucy Elliss-Brookes from Public Health England and Matthew Baker from NCRI Consumer Forum. The research is described in two papers:

• An investigation of cancer survival inequalities associated with individual-level socio-economic status, area-level deprivation, and contextual effects, in a cancer patient cohort in England and Wales BMC Public Health
•  Are deprivation-specific cancer survival patterns similar according to individual based and area-based measures? A cohort study of patients diagnosed with five malignancies in England and Wales, 2008–2016 BMJ Open
•  Project website