Poverty, poor education and other social problems cause as many deaths as major diseases do. That's the conclusion of a study that estimated the number of these deaths by analyzing 27 years of published research.

The Meta-Analysis combined the results of 47 published studies with Census Bureau data. Researchers were able to assign relative risks of mortality to individual social factors and then estimate the number of deaths these factors caused each year. They estimate that about 245,000 U.S. deaths in the year 2000 were due to low levels of education, which is more than the number of deaths from heart attacks (192,898).

The research is the first comprehensive analysis of the relationship between social factors and mortality.

In a similar vein, 176,000 deaths were due to racial segregation, about the same as the 167,661 deaths from cerebrovascular disease (stroke). And the number of deaths from low social support (162,000) was roughly equal to those from lung cancer (155,521).

According to the researchers, these figures offer compelling evidence that public health must be seen in a much broader light than it currently is. Focusing primarily on medical causes of death is not good enough. Truly improving public health also requires improving social conditions.

Other findings included an estimated 133,000 deaths from individual poverty, 119,000 from income inequality and 39,000 from area poverty. Overall, about 4.5% of all deaths were estimated to be due to poverty, with the risk higher for those aged 25-64 than for those over 65.

Of course, it is much harder to definitively state that poor education or poverty caused a death than it is to attribute a death to a heart attack. And the researchers acknowledge that their figures are only estimates. But they think that they're the best estimates currently available. A press release by Columbia University's Mailman School of Public Health, where the research was conducted, calls the research the first comprehensive analysis of the relationship between social factors and mortality.

The researchers conducted a Medline search for all English-language studies published between 1980 and 2007 that contained estimates of mortality due to social factors. They ultimately found 47 such articles suitable for their analysis. They used the data in these articles to calculate the relative risk of mortality for a number of individual social factors including education, poverty, health insurance status, job stress, social support racism/discrimination, housing conditions and early childhood stress.

They then did the same for area-level social factors: area-level poverty, income inequality, deteriorating built environment, racial segregation, crime and violence, social capital and availability of open or green spaces. By obtaining prevalence estimates for these factors, primarily from Census Bureau data, they were then able to estimate how many deaths each factor was responsible for annually.

The researchers hope that these estimates will lead to policies that better address social problems and lower the number of deaths that social factors cause.

An article on the study was published online by the American Journal of Public Health on June 16, 2011 and will also appear in a future print issue of the journal.