When doctors treat their patients, they are essentially performing one of two basic functions. They are either a) addressing a complaint that a patient has come in with or b) identifying screening tests that are appropriate for the patient and performing those tests. The management of chronic disease kind of encompasses both categories. There's also a third function doctors tend to feel obligated to perform which is to motivate health behavior change. I myself feel no such obligation but I often do this anyway (time permitting) because it's fun and because patients are often looking for motivation. It's good customer service.
Accepting for the sake of argument this view of medicine, what does a good doctor do when a 17 year old girl who is 20 weeks pregnant and has had no prenatal care comes into the emergency room with abdominal pain? The good doctor will identify a complaint that needs to be addressed, namely abdominal pain and he will also identify a litany of screening test that should be performed because the patient has had no prenatal care and needs things like an HIV test, gestational diabetes screen, rubella, Hepatitis B, etc. The good doctor will further recognize that her complaint is of vastly greater urgency than any of the above named screening tests. This patient is in the emergency room and screening tests never need to be done on an emergent basis. Let me repeat that for all you OB chiefs and attendings out there who like to make your junior residents do 1 hour glucose tolerance tests on patients in triage: screening tests never need to be done on an emergent basis. They can always wait until the patient has a clinic visit.
I think that in general, when it comes to screening doctors tend, not to forget but rather, to misinterpret their Hippocratic oath - above all, do no harm! There are very good reasons to do certain screening tests, marginally good reasons to do other screening tests and there some screening tests which we have very good reason not to offer. Every test one performs has the potential to come back abnormal. And for every abnormal test, there is some intervention we can perform. And for every intervention we perform, we subject the patient to some increased risk of harm. The only way to determine whether the benefit of screening outweighs the risk is to study the test on a large scale and to determine who does better - the screened group or the unscreened group.
Bottom line is when you're addressing a patient's complaint, by all means, test them for whatever might be causing their symptoms. But be very cautious about testing asymptomatic people for stuff. Something as simple as a cervical exam on a patient who is not complaining of any symptoms consistent with labor is screening. For every patient you help based on your exam findings, you may hurt two or three. We take an oath to do no harm and refraining from unnecessary screening tests is one really easy way to decrease the amount of harm you do as a physician.
