Where we live, what we earn and our access to services can all influence our health. But understanding how these factors interact – and where inequalities exist – requires detailed information about both individuals and the communities they live in.
Over the past 20 years, the 45 and Up Study has given researchers a unique opportunity to examine these differences at scale, helping build a clearer picture of how social and economic circumstances can shape health and access to care.
Looking beyond where people live
One of the challenges in understanding health inequality is how socioeconomic disadvantage is measured.
Researchers and policymakers often use area-based measures such as the Socio-Economic Indexes for Areas (SEIFA), which describe the relative advantage and disadvantage of communities based on where people live.
But research using data from more than 205,000 45 and Up participants showed that this can tell only part of the story.
The 2014 study compared inequalities in heart disease and self-rated health using three measures of socioeconomic status: household income, education and SEIFA.
It found that the apparent size of health inequalities varied substantially depending on the measure used. Inequalities were greatest when researchers looked at household income and smallest when they used SEIFA, with the differences particularly pronounced among people aged 45–64.
The findings highlighted the importance of looking beyond postcodes alone when identifying and responding to health inequality.
Unequal access to healthcare
45 and Up data has also helped researchers investigate whether Australians have equitable access to healthcare.
A 2024 study linked information from 267,153 participants with Medicare and mortality data to examine use of GP and specialist services across NSW.
After taking people’s health needs and where they lived into account, researchers found that people with lower levels of education were more likely to frequently use GP services and experience continuity of GP care, but were less likely to see a specialist.
The researchers concluded that GP care was equitable on the measures examined, but identified socioeconomic inequalities in specialist care. They also found that use of both GP and specialist services varied across local areas, even after differences between the people living in them were taken into account.
Mapping differences across NSW
Other research has used 45 and Up to show how healthcare access can vary geographically.
A study of more than 234,000 participants mapped cataract surgery across 88 areas of NSW over a decade. Researchers identified substantial geographic variation, with the incidence of cataract surgery generally decreasing from coastal areas towards north-western inland NSW. Socioeconomic circumstances and private health insurance were also associated with differences in the incidence of cataract surgery.
Encouragingly, areas with particularly low incidence of cataract surgery became less concentrated over the decade studied, suggesting the geographic distribution of services improved over time.
Twenty years of seeing the bigger picture
These studies demonstrate why large-scale longitudinal research matters for understanding health inequality.
45 and Up combines information participants provide about their health, lives and circumstances with the ability to link to health and other records. This allows researchers to look beyond population averages and investigate how individual circumstances, geography and use of health services intersect.
Over 20 years, the contribution of more than 250,000 participants has helped researchers identify where inequalities exist and build evidence that can support better-informed health policy and services.
As we celebrate 20 years of 45 and Up, we thank our participants for making this research possible – and for helping us better understand not only how Australians age, but how the circumstances in which we live can shape our health.
