Episode 45: Sample this preventive medicine from the USMLE Audio Series at Medical-School-Podcast.com

Preventive Medicine

Preventive medicine, basically, has three tasks – screening, counseling, and immunization.  We are going to be focusing on screening and immunization.  About 15 minutes we’ll go over some screening principles, 15 minutes we’ll go over some principles regarding immunization.

Primary Prevention

So when you talk about preventive medicine and prevention, you can talk about it and think about it as primary prevention, secondary prevention, and tertiary prevention.  In primary prevention, you are actually working on reducing risk factors before a disease or a condition has occurred – so, immunizing somebody so they don’t get tetanus, you know, treating somebody who doesn’t have coronary artery disease with hyperlipidemia therapy to prevent them from getting heart disease.

Secondary Prevention

Secondary prevention talks about detecting a disease or a condition to improve prognosis – to do a mammogram to get an early stage breast cancer where that disease will be treatable and curable.

Tertiary Prevention

Tertiary prevention is another concept we don’t think about that much, but that would involve reducing risks of getting a second event.  So, if somebody has coronary artery disease, you put them on a high dose hyperlipidemic therapy to prevent their – or reduce their incidence of getting a follow-up disease.

There are a number of terms that you need to know in preventive medicine – that are listed up here.  These are covered very nicely in your book in chapter four.  And I believe Dr. (Stoller) will be reviewing some of these at the end of the day as well.  So, I’m not going to touch on these.

Screening Tests

So let’s talk about screening.  What are the general principles of screening?  Well, the disease that you’re screening for or condition should be important – meaning it should have a significant morbidity or mortality.  It should also be common.  It should have a high prevalence and a high incidence.  The disease that you screen for, you should be able to treat.  And the tests that you use to screen should be accurate, getting at the sensitivity, specificity, and predictive value.

Costs of Screening

And, finally, the screening tests should have a reasonable cost, not only financial in regards to quality of the life you’ll save, but also to the patient.  A screening test should be a low-risk test.

So when you look at the – number one – two causes of mortality in United States in 2002, you can see that the big players are heart disease and cancer.  So these are the ones who we would want to screen for the most.  And, obviously, the age where you screen somebody or practice preventive medicine varies.  So, obviously, in your older population, heart disease and cancer will be much higher on the list, whereas in your younger population, accidents, suicide, homicide, unfortunately, has a higher prevalence.

This very interesting slide shows the change in the United States death rates by cause between the years 1950 and 2002.  You can see that there has been a marked decrease in the rate per thousand deaths for heart disease, cerebral vascular disease, and also infection disease.  But the curve or the bar graph for cancer is relatively flat.

So let’s talk about, briefly, a couple of slides about cardiovascular screening.  We don’t have time today, but I think this will be covered at other sessions during the course about screening for blood pressure, lipid guidelines, diabetes guidelines.

EKG Screening?

I wanted to just make sure that you are aware.  According to the United States Preventive Services Task Force, if you have a 40-year-old patient who comes in without any risk factor who is healthy, there is no indication to do routine stress te...