Breast cancer is the second leading cause of cancer death in US
women. According to the American Cancer Society , an estimated
46,000 women died from this disease in 1995, and 182,000 new cases
were diagnosed. Over 50% of US breast cancer patients are working-aged
women. Thus, the morbidity, mortality, and costs of this cancer
have a significant impact on working women and their employers.
Epidemiologic studies have shown that one of the most effective
ways to reduce breast cancer mortality and morbidity is through
early detection with periodic mammographic screening. Although
screening does not prevent breast cancer, it can increase the
likelihood that it is detected at a stage when it can be treated
more effectively. Several trials have shown that routine mammographic
screening may reduce breast cancer mortality by up to 30% [2-5].
The magnitude of this benefit is particularly large among women
age 50 or older, who are at higher risk of breast cancer.
The value of routine mammographic screening in women under age
50 years who have no known risk factors is a source of considerable
controversy [6-8] (see also "Screening Mammography for Women Aged 40 to 49?").
However, recent data suggest that a reduction in mortality also
may be demonstrated for women 40 to 49 years old . Modern screening
and diagnostic techniques may further improve our ability to reduce
breast cancer mortality in women older than 40 years .
As the benefits of periodic mammographic screening have become
apparent, initiatives have been developed to promote the value
of screening to employers and to help launch screening programs
in the workplace. These programs can be classified broadly according
to the types of arrangements made by employers to provide mammographic
screening. Some employers own their own mammography equipment
and provide mammographic screening, breast physical examinations,
education, and counseling services at the workplace. Others contract
with mobile mammography units that visit the workplace. Some of
these mobile units also may provide other types of services. Other
employers simply include routine screening in their basic health
benefits package and help coordinate access to screening mammography,
but play no active role in the promotion or follow-up of screening.
Although the health benefits of screening mammography relative
to reducing mortality and morbidity are well-known, less is known
about the costs of attaining those benefits through screening,
or about whether any cost savings are associated with those health
benefits. With the current emphasis on the cost of health care,
relative to its benefits, the development of a successful mammographic
screening program in the workplace may depend not only on the
health benefits that it produces but also on the program's costs
and cost savings to the employer and employee. In this article,
we explain the types of costs and savings associated with mammographic
screening in the workplace, and discuss several options to improve
the efficiency of a screening program.
Several types of costs are associated with establishing and implementing
a mammographic screening program in the workplace .
For companies that provide screening using their own equipment,
costs include those for purchase and maintenance of the mammography
machine, certification, and dedicated space to house the machine.
Other costs include those for a technician to perform the mammograms,
a physician to interpret them, and a nurse to provide other types
of services related to the screening program, such as clinical
breast examinations. Companies that perform screening in the workplace
using their own equipment may contract out for film processing
Other companies may elect to provide mammographic screening at
the workplace through a mobile mammography unit for a fixed price
per mammogram. Yet another option is to pay a fixed price to an
off-site facility. Estimates of the average cost per mammogram
range from $35 to more than $100, depending on the type of mammographic
screening provided (two- vs single-view), other services provided
(eg, clinical breast examination, instruction in breast self-examination),
and the number of employees screened.
Costs of Lost Productivity
Other costs that a company incurs when employees are screened
relate to lost productivity during screening. If an employee must
travel off-site during business hours, her productivity to the
company is lost for that period of time. This lost productivity
is the value of goods and services that the employee could produce
during this time and, according to economic theory, is equal to
the employee's wage. Recent estimates of lost productivity due
to mammographic screening range from 2 to 4 hours for off-site
screening, and ½ to 1 hour for screening at the workplace.
Therefore, on-site screening may be an attractive option for companies
that must hire temporary help if a regular employee is absent.
This could be particularly relevant to manufacturing companies,
where the absence of an employee has important implications for
the production process.
Costs of Further Diagnostic Tests
Other costs are not due to screening itself, but rather, relate
to the diagnostic work-up that follows a suspicious mammographic
finding. A diagnostic work-up usually includes additional mammographic
views, with or without compression of the breast. Additional imaging
with ultrasonography may be necessary to distinguish cystic from
Abnormalities in any of these diagnostic evaluations may necessitate
a consultation with a general practitioner followed by a surgical
consultation; an invasive procedure, such as needle-core or open
biopsy, to obtain a specimen; and a pathologic work-up and interpretation
to make the diagnosis. These diagnostic work-ups result in costs
associated with medical care, as well as lost employee productivity.
The impact of diagnostic work-ups on the overall cost of screening
depends on several factors. One of the limitations of mammographic
screening is that, like most other tests, it is not perfectly
accurate. (Its limitations are related not only to the radiographic
technology but also to the interpretation of the image.) That
is to say, sometimes a mammogram fails to detect a cancer, and
sometimes it results in a suspicious finding that turns out not
to be cancer.
When a mammography screen fails to detect a cancer, treatment
is delayed and the cancer may result in more severe clinical consequences
and additional costs. When a mammography screen produces a suspicious
finding that is not cancer, unnecessary costs for further diagnostic
work-ups may be incurred. The number of women with suspicious
findings that are not cancers increases when the underlying incidence
of cancer in the screened population is low. The following examples
serve to illustrate this point.
These examples illustrate the association between the accuracy
of mammography; the prevalence of cancer in a hypothetical, previously
unscreened population; the number of missed cancers; and the number
of unnecessary work-ups. The number of missed cancers and unnecessary
work-ups depend on: (1) the sensitivity of mammography (the probability
of a suspicious finding on a mammogram, given that a cancer is
present); (2) the specificity of mammography (the probability
of no suspicious finding on a mammogram, given that no cancer
is present); and (3) the prevalence of undetected cancer (the
number of undetected cancers per 100,000 women) in the population.
The first scenario (Table 1) assumes a population of 100,000 women
whose average age is 55 years and who are not undergoing regular
mammography, in which the anticipated prevalence of undetected
breast cancer is .6% (ie, 600 cancers are present, but not yet
detected). It further assumes a sensitivity of 91.5% and a specificity
of 90% for a standard two-view mammogram, which is consistent
with the performance of mammography under favorable conditions.
As shown in Table 1, of the 600 cancers in this population, 549
are detected through mammography. However, 51 cancers not detected
through mammography would progress and be detected through a subsequent
screen or through clinical symptoms. Also, most women without
cancers (89,460 out of 99,400) do not have a suspicious finding
on mammography. However, because the number of women without cancer
is large, even though the specificity of mammography is quite
high, only 5.2% (549/10,489) of suspicious mammograms actually
result in the detection of cancer through a diagnostic work-up.
Therefore, approximately 20 diagnostic work-ups are performed
for each cancer detected.
As the prevalence of cancer in the population decreases, more
diagnostic work-ups are performed for each cancer detected. The
second scenario (Table 2) again assumes a population of 100,000
women whose average age is 55 years. However, this population
is assumed to be receiving regular mammographic screening, and
therefore, the prevalence of undetected breast cancer is only
2% (200 cancers are present but not yet detected).
As shown in Table 2, with the same sensitivity and specificity
of mammography, only 2% (183/10,163) of suspicious mammograms
actually result in the detection of cancer. Therefore, as the
prevalence of cancer in the screened population decreases, a larger
portion of diagnostic work-ups are unnecessary, resulting in a
larger proportion of costs that are unnecessary.
For purposes of simplification, this example ignores the fact
that some suspicious findings on mammograms will result in detection
of benign breast disease through a diagnostic work-up. Therefore,
in screening programs clinical benefits may accrue even if cancer
is not detected.
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