Researcher: Racial Health Disparities Calls for Vigilant Journalism

Thomas LaVeist, a researcher who specializes in health disparities, still remembers the time in grad school when he chanced upon a used copy of “A Night to Remember,” an old nonfiction book that tells the story of the Titanic’s final hours.

Tucked away in the book, LaVeist found the following breakdown of survivors: While 97 percent of those in first-class survived, only 55 percent of third-class passengers made it.

“This fascinated me as an interesting analogy to the U.S. health system,” LaVeist, director of the Hopkins Center for Health Disparities Solutions, told fellows at last week’s 2013 National Health Journalism Fellowship.

“Even here when all three cabins went down, we had this disparity in who survived. It says to me: Who you are determines who gets access to resources.”

It turned out to be a formative insight for LaVeist, whose subsequent career has extensively documented the links between race, class, place and health. While health disparities are often framed as a social justice issue, LaVeist makes the argument that maintaining such disparities is expensive as well. It costs the United States more than $1.2 trillion dollars over a three-year period, one report estimated.

“It also costs money to have health disparities – to not do anything at all,” he said.

While LaVeist says that “the absence of policy is part of the problem,” he is also highly critical of both popular and academic accounts of why different racial groups and classes experience very different health outcomes.

“We’ve done a lot of things, but I think much of what we’re doing is going to fail, because we haven’t first stopped to diagnose the problem,” he said.

Beware the Pitfalls in the Research

While most every health journalist knows to look out for statistical sleights-of-hand on a general level, LaVeist urged vigilance heightened when it comes to multivariate analysis and small sample sizes.

Multivariate analysis is a widely used statistical technique that helps researchers tease out the relative effects of multiple variables. But as with other statistical tools, the accuracy of the technique can be dramatically limited when sample sizes are too small. LaVeist pointed to a national health survey (an exceptionally large data set) that nonetheless included only eight data points in one of the demographic categories he was examining -- African Americans in the highest income bracket that have at least one disability.

LaVeist’s point is that if one of the largest data sets available has such a limited number of data points in some categories, then researchers and journalists should be even more careful when drawing conclusions based on smaller data sets – certain groups or “cells” within the data might not have enough data points to say much of anything.

“Imagine how much more pronounced the problem is in smaller data sets,” he said.

LaVeist suggests that too-small data sets should trigger journalists to question any health disparities research built upon them.

“Much of what we think we know about health disparities I’m not convinced we actually know because the quality of the research is simply not good enough – because many of the data sets we have simply cannot sustain the research we want to do,” he said.

The more variables are added to a multivariate analysis, the larger the sample size needs to be to ensure useful results. “Every time you add another variable, you need to increase the sample size to make sure you have enough people in each of these individual categories to do the analysis,” he said.

Sample sizes aren’t the only potential hazard of disparities research. Isolating exactly which variable is responsible for a given health disparity can easily be confounded by marked differences in neighborhoods and places.

“Any national study on race disparities suffers from this problem – that the people that you’re comparing are living in completely different types of communities and exposed to very different risks,” LaVeist said. “And that the disparities that you find you can’t say are about race per se except to the extent that race determines place, and therefore place determines health.”

LaVeist made this point more fully in a 2011 report titled “Segregated Spaces, Risky Places: The Effects of Racial Segregation on Health Inequalities”:

“Community-level poverty proved a more important determinant of health status than neighborhood racial composition,” the report says, adding that “racial inequalities in health status and outcomes are predominantly the result of place. Race helps to determine place, and in turn, place influences health.”

Low-income inner-city blacks in Baltimore who grow up surrounded by corner stores selling malt liquor, wine and lottery tickets face a very different set of health risks than, say, middle-class blacks living in View Park, Los Angeles. Differences in place and income often trump the predictive power of race, according to LaVeist. Similarly, when it comes to making comparisons between different racial groups, LaVeist said he has more confidence in studies that examine groups of people from the same environment – blacks and whites who are both from inner-city Baltimore, for example.

That’s not to suggest race plays no part in health disparities, however. If place can shape your health, then it matters that minorities are far more likely to live in poor, segregated neighborhoods and suffer poorer health as a result. But there is also evidence that race can more directly determine what kind of treatment a patient receives.

A number of studies have shown black patients are less likely than white patients to receive certain procedures. In a 2003 study that LaVeist conducted called “The Cardiac Access Longitudinal Study,” he and his co-authors found that in three urban hospitals in Maryland, about 80 percent of eligible white patients were referred for a procedure called cardiac catheterization, while less than 60 percent of black patients were referred for the same diagnostic procedure. The two groups were otherwise comparable, had the same health insurance and saw the same physicians.

“One-hundred percent of these patients should have been referred for cardiac catheterization,” LaVeist said. “We have a quality problem, which is a general problem we have in this country, but then we have this disparities problem as well.”