As health-equity researchers, it's part of our job to measure the relationship between social conditions and health outcomes. Often, we try and link one social condition, such as income, to one health outcome, such as diabetes, low birth weight or mental illness -- the list goes on.
This approach enables us to demonstrate when low income is associated with a higher risk of having a specific problem. What we don't generally measure, however, is the overall impact of low income on physical and mental health.
What happens when we try? At the Centre for Research on Inner City Health, we analyzed health-survey data representative of more than 75,000 Canadians who recently gave birth. We looked at the relationship between low income and the risk of experiencing three to five of these health conditions at the same time: adverse birth outcomes, postpartum depression, serious abuse, hospitalization during pregnancy and frequent stressful life events.
The results were staggering.
We found new mothers living on very low incomes were 20 times more likely to experience multiple health problems than those on high incomes. Compare this to the "single disease" method through which we often find people living on low incomes are only twice as likely -- if that -- to experience a specific health problem.
Our evidence also suggests if we were able to ensure all new mothers in Canada had household incomes of more than $50,000 a year, we could reduce the occurrence of multiple health problems in pregnancy by 60 per cent.
These findings tell us low income doesn't just lead to one disease or another. Instead, it has wide-ranging impacts on the health of individuals and communities. They also tell us, as researchers, we've been using the wrong tools and underestimating the full impact of income on health.
So now we have a more accurate assessment of the impact of low income on well-being, what kind of solutions do these findings suggest?
To some degree, the health-care system is already recognizing some populations face multiple health problems. Recent responses have included an emphasis on case co-ordination and collaboration between different parts of the system such as primary care, hospitals, home care and long-term care. These are good things. Programs such as diabetes-education centres and stress-reduction classes can be good things, too.
The health-care system, however, is not the only place, or even the most important place, to focus on to improve the health of the population.
Instead, our evidence suggests the potential of focusing our attention on low income itself. If we want to know how to improve the health of Canadians on a large scale, programs and health-system changes -- while very important -- are not the answer. The answer is to institute policies that address the social determinants of health, such as education, housing and employment, and change the conditions themselves.
What does this look like in practice? We can start by acknowledging our health is largely determined by factors that sit outside of the health-care system. Many people know this, but now we have data and some startling numbers to back it up. As a result, we can see, in a very real sense, social policy is health policy.
We should foster collaborations between sectors such as housing, health and employment, and between levels of government to co-ordinate services and measure health impacts. We must invest in policies that address income. There are many opportunities, from bringing income-assistance programs, unemployment benefits and minimum wage in line with the real cost of living, to boosting provincial child benefits to the level needed to make sure all children across the country lead healthy lives.
The evidence shows us the health of mothers, babies and families is at stake, and there's no more time to lose.
Dr. Patricia O'Campo, an expert adviser with EvidenceNetwork.ca, is a social epidemiologist and the director of the Centre for Research on Inner City Health at St. Michael's Hospital in Toronto. She is also a professor at the Dalla Lana School of Public Health Sciences at the University of Toronto.