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Until there is good
evidence from clinical trials, deciding about screening in older
people will require keen clinical judgment. However, the decision
making process need not be entirely a matter of guesswork. For
example, compare these two options:
| Option 1: low recommendations based upon expert opinion
| Option
2: Individualize the decision to continue screening
elderly patients
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This
option involves guidelines that reflect scientific
uncertainty; for example:
- The
American College of Physicians-American Society
of Internal Medicine recommends against routine
screening mammography for breast cancer in women
older than 75 years of age
- The
U.S. Preventive Services Task Force states that
evidence for or against routine screening in women
over 70 years of age is insufficient to make recommendations
- The
American Cancer Society and American Medical Association
cite no upper age limit for routine screening.
|
This
option requires:
- A
good estimate of the benefits and harms with screening
for each patient
- Knowing
the patient's feelings about:
- the
experiences of screening itself
- testing
after an abnormal result
- treatment
of the disease if it is present
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In both options, the
decision to screen (or not) involves making an estimate of the
patient's life expectancy. Why? A woman can't benefit from screening
if she won't live long enough to reap the benefits of screening;
but, she can suffer the harms of testing and diagnosis.
In the next several
sections, case studies help to explore how estimating life expectancy
in people with chronic disease can influence clinical decisions
to screen (or not screen) for asymptomatic disease. We examine:
- Principles of screening
in the elderly
- How to estimate
life expectancy
- A practical approach
to making screening decisions
- Calculating the
impact of co-morbid illness
- Adjusting life expectancy
for co-morbid illness
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