Untangling the mysteries of multiple morbidity

June 18, 2018

Associate Professor Anda Botoseneanu’s recent research reveals why some combinations of chronic diseases can be particularly dangerous.

A growing number of Americans are facing a snowballing list of chronic conditions. One in three adults are now considered obese. Type II diabetes impacts almost 1 in 10, or about 30 million people. And the CDC estimates nearly half of Americans are at risk for some form of cardiovascular disease. What’s more, two out of every three Americans 50 and older are managing two or more chronic diseases.

Health Policy Studies Associate Professor Anda Botoseneanu said it’s this last phenomenon—what’s known as “multiple morbidity”—that’s particularly concerning. And it’s not simply because having two or three diseases is worse than having one. It’s because, according to her recent National Institutes of Health-funded research, some combinations of chronic conditions can have a whole-is-greater-than-the-sum-of-its-parts effect on your level of disability.

Botoseneanu and her longtime collaborator, Ana Quiñones of Oregon Health and Science University, discovered that for some disease combinations, chronic conditions that produce low levels of disability on their own can actually create high levels when they occur together. Somewhat surprisingly, one of the more pronounced examples of this phenomenon was not among people living with two physical conditions (for example, diabetes and cardiovascular disease); it was with people who had a physical condition, like diabetes, and a chronic mental health condition, like depression.

“Diabetes is sort of the poster condition for self-management,” Botoseneanu said. “It’s a very long-term condition, where accurate and constant management is required in order to delay complications. But you add depression to the mix, and someone might not be able to manage their diabetes effectively; they may, for example, have trouble keeping their doctor’s appointments or feeling motivated to check their blood sugar. And that could quickly lead to a far more severe or acute course for that disease than it might have otherwise.”  

Botoseneanu said the finding could have important clinical implications for treatment of certain chronic conditions. For instance, using the above example, she said it’s not routine for physicians to screen diabetes patients for depression, but it’s quite common to screen for cardiovascular disease—even though the former may be the more disabling combination.  

“The big takeaway for people who have multiple chronic conditions is: Try to screen for and prevent depression, because that’s what adds a significant level of disability,” she said.

Botoseneanu and her colleagues are now digging into two more big questions sparked by the findings. First, they’ll attempt to identify which particular disease combinations seem to pose the greatest risks. (The team identified 1,700 different combinations in all and 17 that are quite common.) Second, they want to investigate why chronic conditions seem to evolve differently in different demographic populations.

“Both obesity and multimorbidity vary tremendously among different ethnic groups,” Botoseneanu said. “The biggest difference is between whites and African Americans, who have higher levels of obesity and tend to add diseases more quickly over the course of a lifetime. Hispanics, on the other hand, tend to look more like whites in their health outcomes, but are more like African Americans socioeconomically. So the interesting question is, of course, why.”

The team is now pursuing another major National Institutes of Health grant to unravel those mysteries and more. In doing so, they hope to uncover creative new ways to help the growing number of Americans living with multiple chronic conditions.

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