A story by CBS news plays up a new study in the American Journal of Epidemiology that could give anyone reason to feel optimistic: Optimism itself is linked to a longer life, at least based on a survey of professional nurses over the years. The survey used by the researchers was the Nurses’ Health Study (NHS), which reaches out to tens of thousands of medical nurses every 2 years and asks them basic questions. The data is often used to help guide public policy.
The story attempts to lay out the potential benefits of optimism and their relation to various diseases and longevity–but it did so using relative risk numbers, which are not reflective of the true impact. The story also missed an important discussion about how much the results could stem from having good health–that perhaps this causes the optimism, and not vice versa. Also, no independent sources–who could provide insight and some skepticism–were included.
Most everyone on Earth wants to live longer, but we often have trouble picking the healthy behaviors that lead to longevity. If a sense of optimism — a totally cost-free medical intervention — could help encourage the right behaviors, extend lifespan, and improve the quality of life, that’d be a boon around the world. Unfortunately, it’s a devilishly tricky question to ask, given the strong counterargument: Maybe healthy people just feel more optimistic because they’re doing well, while sick or injured people have a lot more to worry about and feel more pessimistic. This nuance is important to convey to readers given the limitations of this study–how it couldn’t prove cause and effect.
Optimism is free of charge, and anyone who says differently is overly optimistic about stealing your money.
Readers are told that the most optimistic nurses (top 25%) had nearly a one-third lower chance of dying, at least compared to the the most pessimistic group (lowest 25% of the survey group for optimism). We’re also clued into some of the data behind the longevity numbers: the drop in risk of diseases and conditions that kill the most Americans. For example, according to the study’s analysis, the most optimistic nurses had a 39% lower risk of having (and dying from) a stroke.
The problem? All these numbers are presented in relative risks, instead of absolute risks. To know how meaningful these findings were, we need to see the absolute risk of death among the most optimistic of nurses compared to the least optimistic.
Being overly optimistic can put people into harm’s way — say, thinking they’re better drivers than they really are, and upping the risk of an accident. (There are a number of studies about this very thing.) But that’s a kind of common sense we don’t think needs calling out in a story.
The story’s phrasing on the evidence was direct and clear: it was “observational and cannot prove a cause-and-effect relationship between optimism and a longer life.”
However, this caveat didn’t come until the ninth paragraph in the story, and was preceded by a headline and several statements that suggested a cause-and-effect relationship was at hand. The story also ends with advice on how to become more optimistic to achieve better outcomes. For these reasons, the story is not satisfactory on this criterion.
Also, an important limitation to this research wasn’t discussed: One reason people may self-identify as optimistic is because they’ve never endured the mental and physical setbacks of someone who’s experiencing or survived a significant medical or mental issue.
There’s no sign of dramatic or charged language here.
Two of the study’s authors are interviewed. Chatting with an outside source would definitely have strengthened this story, and may have exposed the reverse causation issue we previously brought.
The story does discuss healthy dietary choices and exercise.
Optimism may not be FDA-approved, but we’ll optimistically assume all readers know that it’s widely available. There could have been more included on how optimism can be a learned skill, for those who would like to become more optimistic.
The story explains what’s novel here is how the research looks at all-cause mortality vs specific health behaviors and outcomes. This is established with this statement:
“Optimism in prior research has been shown to be related to better health behaviors and better health outcomes, particularly in cardiovascular disease,” postdoctoral research fellow Kaitlin Hagan, co-lead author of the study, told CBS News. “So in our study we wanted to expand that and look at all-cause mortality and be able to see whether optimism improves other health behaviors that then affects mortality, or whether there’s an independent effect of optimism on mortality.”
The reporting here appears to be original, as we didn’t detect any copy/pasted quotes.