DURHAM, N.C. -- Obese people are less likely to receive
preventive services such as mammograms, Pap smears and flu
shots from health care providers, according to an analysis of
health care data by Duke University Medical Center
researchers.

The Duke study showed that, for a sample of white
middle-aged women, as body mass index (BMI) went up, the odds
of receiving mammograms and Pap smears went down. BMI is a
measurement of body fatness based on weight adjusted for
height. In data gathered in 2000, a white woman of normal
weight was more than 50 percent more likely to receive a
mammogram than a severely obese white woman (BMI greater than
40), the study showed.

The researchers found a similar inverse correlation between
obesity and flu shots among elderly white women and men.
However, they found no significant association between obesity
and all three preventive services among black study
participants.

"Despite knowing that obese women have a higher risk of
breast and cervical cancer, and the obese elderly have a higher
risk of complications from flu, obese people are less likely to
receive clinical preventive services," said Truls Ostbye, M.D.,
Ph.D., lead study author and a professor in Duke's department
of community and
family medicine.

Based on their analyses, Ostbye and his co-authors found
that income, education and access to health care were not
important reasons for the discrepancies in care. The
researchers suggest that significant causes may include social
stigma, avoidance of health care by patients and bias by health
care providers.

The results of the Duke study were published in the
September 2005 issue of the American Journal of Public Health.
The study was funded by the National Institute on Aging and the
National Institute of Diabetes and Digestive and Kidney
Diseases, both part of the National Institutes of Health.

The Duke team examined data from the Health and Retirement
Study (HRS) and its companion, the Asset and Health Dynamics
Among the Oldest Old (AHEAD) study. The studies began
collecting information in 1993 to determine how retirement
impacts the health and wealth of U.S. men and women. The
studies are funded by the National Institute of Aging. In the
HRS, 12,652 participants aged 50 to 61 in 1992 have been
interviewed periodically about their health behaviors, disease,
disability and medical care usage. The AHEAD study, which
collects similar data, includes 8,124 seniors aged 70 years and
older.

Ostbye and his co-authors examined data on mammograms, Pap
smears and influenza vaccinations because these preventive
services have been shown to be effective in preventing serious
illness. The U.S. government has also placed a high priority on
these health care services in Healthy People 2010, which
identifies the nation's most significant health concerns and
formulates action plans to address these concerns. Healthy
People 2010's goals include mammograms for 70 percent of
middle-aged women every two years and Pap smears for 90 percent
of middle-aged women every three years. Also, 80 percent of the
elderly should be vaccinated against influenza annually,
according to the goals.

The Duke analysis of the data showed that while the overall
number of tests provided to study participants increased from
1995/1996 to 2000 – the years included in the study – the
disparities between normal weight and obese people remained
constant, Ostbye said.

In 2000, more than 78 percent of women with a normal BMI
(18.5-24.9) received mammograms. Only 71 percent of women with
a BMI above 40, which is "Class III" or severe obesity,
received mammograms.

The difference between study participants was greater for
Pap smears. In 2000, 73 percent of women with normal weight BMI
received Pap smears, compared to less than 54 percent of women
with a BMI greater than 40.

The researchers also found a significant decrease in the
proportion of study participants who received flu shots as
their body mass increased. More than 78 percent of men and
women with a normal BMI received flu shots in 2000, compared to
only 57 percent of people with a BMI greater than 40 received
flu shots, the researchers found.

Co-authors include Donald H. Taylor, Jr., Ph.D., Terry Sanford Institute of Public
Policy at Duke University and Duke University Medical
Center; William S. Yancy, Jr., M.D., Duke University Medical
Center and the Veterans Affairs Medical Center in Durham, N.C.;
and Katrina M. Krause, Duke University Medical Center.