When it
comes to providing clear explanations of complex medical and health-related
issues, there is no one better than Aaron Carroll. As a person who is regularly
looking for answers in these areas, I am a huge fan. I watch his videos on
Healthcare Triage, read his articles in the New York Times, and follow him on
Twitter. His excitement about food, ideas, travel, and the latest exploits of
his kids are fun to read about. You probably sense that there is a “but” coming
– and here it is: Aaron’s enthusiasm about large studies makes me uneasy.
Large
studies inform us about what happened to a particular group of individuals
under a specific set of circumstances. They can provide guidance for medical
practitioners when they deal with individuals who appear to be similar to that
group; they can give doctors an idea of what to look for. What can large
studies tell doctors for certain about any given individual? Absolutely
nothing.
Problems
arise when the guidance provided by studies morphs into a hard-and-fast rule
about what must always or never be done. In some cases conclusions from studies
are over-generalized and made to apply to situations which are beyond the scope
of the studies.
“Arthroscopic Surgery Isn’t Going to Fix Your Knee,”
a recent HCT video, talks about a recent review and meta-analysis of studies on
arthroscopic surgery for degenerative knee. Both the title and the video itself
make it sound as though arthroscopic surgery is always a waste of time and money. Yet the studies were really about
attempts to repair degenerative knees. They weren’t intended to address the
issue of repairing knee injuries.
When
patients fail to conform the rules derived from large studies, they may have
great difficulty securing proper medical treatment. Here is what happened to a
friend of mine, a man in his mid-seventies, a natural athlete who was then
playing racquetball a couple of times a week. One afternoon he tripped as he
was going up some stairs. In instant he went from normal to hardly being able
to walk.
After an
x-ray at the hospital, he went to a local orthopedics practice where the first
doctor said, “You have a torn meniscus. It can be repaired with arthroscopic
surgery – we do it all the time.” That sounded fine to my friend but when he
was passed along to a surgeon in the same office he got a different pitch. The
surgeon said, “You have advanced arthritis and surgery would not do any good.”
He then gave my friend a cortisone shot, which had no effect on his pain or
disability and told him that he would probably require a knee replacement in
the foreseeable future.
The story
about advanced arthritis didn’t sound quite right to my friend. Before the
injury, he had been able to squat down and remain there for minutes at a time
(the pose of cowboys in front of a campfire). He sought out a second
orthopedist. This doctor, a woman, said, “We don’t normally do knee surgeries
on people in their seventies but I think you are the exception.” Several weeks
later, after performing the surgery, she said, “This knee was like a Ping-Pong
ball. I’ve seen people in their forties who didn’t have knees as good as this.”
This was an injury, not advanced arthritis. The first surgeon had lied because
he didn’t want to operate on a man in his seventies. My friend went back to
playing racquetball.
Doctors
today have impossible schedules. They see each patient for fifteen minutes, if
that. Under these circumstances, over-generalizations and rules based on large
studies can become a tempting substitute for close observation and careful
analysis of an individual situation. The likely consequences are improper care
for the patient and unnecessary expense for the health care system. In thinking
about my friend’s experience I have sometimes wondered how many older people with
injured, but otherwise healthy, knees have been steered into having knee
replacements when all they needed was a simple arthroscopic surgery.