To help people become more comfortable
with numbers and more in control of their
health care decisions, researchers are
studying both how cancer patients interpret statistics and the best way to present
math facts. For example, researchers
at Duke University in Durham, North
Carolina, surveyed 105 breast cancer
patients with hormone-sensitive tumors
who had been given four post-surgery
treatment options and the 10-year cancer-free survival rate for each treatment.
The researchers reported that the
women who had a good understanding of
math underestimated their own chance of
being cancer-free in 10 years, but not by
much. The women who didn’t understand
math estimated their chance of being
cancer-free for 10 years to be about 40
percent, even though the actual range was
between 64 and 92 percent.
Other studies suggest individuals
who are less skilled in math “are more
influenced by other information,” such
as stories from other survivors, says
Ellen Peters, a psychologist at Ohio State
University in Columbus who helped
conduct the Duke study.
Emotions play a role, too. “Everybody is
really worried [about their cancer], and we
know that someone who is [worried] tends
to perceive treatment benefits as lower and
risk as higher,” says Peters. Math-savvy
women can balance their worry by returning to the numbers, but women who don’t
feel comfortable with math may be left
with more worry or have less confidence in
a treatment’s benefits.
In a study published in February 2017
By the Numbers
in Breast Cancer Research and Treatment,
researchers surveyed women diagnosed
with early-stage breast cancer to learn
about how their doctors had talked to
them about their risk of recurrence.
They found that the more uncomfortable
a patient was with numbers, the less the
doctor discussed the risk of recurrence.
Feeling comfortable with numbers makes
a difference, says Brian Zikmund-Fisher,
a health communication researcher
at the University of Michigan School
of Public Health in Ann Arbor who
co-authored the study. “The patients
who have low numeracy [comfort with
numbers] need the most help. But if
their doctors aren’t talking with them,
they get a double whammy,” of not
getting information and not knowing
how to ask the right questions.
Zikmund-Fisher is testing different
ways to use graphs and diagrams to
present numbers related to everything
from blood test results to cancer-related
risk factors. Other researchers are
investigating whether patients under-
stand more if they see certain types of
pictures along with written explana-
tions. “When we acknowledge that
numeracy is a barrier,” Zikmund-Fisher
says, “then we can think about how to
overcome it.” —CAMERON WALKER
FORWARD LOOK | BEYOND THE NEWS
COMFORT WITH MATH MAY AFFECT
Talking to doctors about cancer and its treatment often means being bombarded with numbers, from percentages to risk ratios. Yet many people don’t fully comprehend
what the numbers mean. As a result, cancer patients may not
understand their prognosis, the effect a treatment might have,
or their risk for recurrence.
FDA Sends Warning Letters to Companies Selling Unapproved Cancer Treatments
On April 25, 2017, the U.S. Food and Drug Administration (FDA) issued 14 warning letters
and four online advisory letters to companies selling more than 65 products that claim to
prevent, diagnose, treat or cure cancer. These products—such as pills, creams, ointments
and oils—have been marketed without FDA approval and have not been shown to be safe
or effective. Over the past 10 years, the FDA has issued more than 90 warning letters to
companies marketing hundreds of products that make false cancer-related claims.
LEARN MORE ON THE FDA’S WEBSI TE, FDA.GOV.
• Ask for numbers. Even if you’re not comfortable
with numbers, asking for them will help you and
your doctor begin to talk about them.
• If a doctor gives you a statistic about recurrence or
side effects you don’t understand, ask how likely it
is to happen to you. The most important thing is to
know what the numbers mean for your health.
• Sometimes doctors use relative risk, a statistic
that compares one group with another, to describe
an outcome. Ask instead for the absolute risk—the
likelihood of an event actually occurring—so that you
get a clearer picture of what the numbers mean for you.