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Test Taking Strategies for USMLE Step 1 Questions

by Pravin Shukle, MD
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    00:00 Let's take a look at the exam itself. Remember that long-stem questions are actually quite hard and they take a long time. Read the last 2 sentences first and then go back and read the stem because sometimes the stem is not relevant to the question itself. Let me show you an example. Let's take a look at this case here I've got on my computer. A 2-year-old is brought into the ER by his panicked parents. His parents said that he ate some pills, possibly antibiotics. His father blah, blah, blah, blah, blah, kind of gets boring. Let's look at the last 2 sentences of that question and I'm going to highlight them for you so you can see it nice and clear. The bottle label says that the substance has a pKa of 3.8. What percentage of the drug will be hydrophobic or lipid soluble in the small bowel at a pH of 4.8? If you think about it, this is a pH question, this is not about a clinical case. It's really about figuring out how to use pKa and pH to figure out the percentage of soluble ions. Right? You don't need the rest of that.

    01:08 This particular question you can see that the stem is really not relevant to the rest of the exam and so this way you can come up with the answer. Now we're going to do the same question on the lecture so have a look for this question later. The next thing I want you to be aware of on exams are what I call fuzzifiers. I know that's not a real word but I'll show you exactly what I mean. Let's look at another question on my computer. So this is a non-sensical question obviously. "We spent millions of dollars trying to answer which species Goofy belongs to. Goofy is: A. Definitely a dog. B. Not a dog. C. Maybe a mutated dog that talks and Pluto is a regular dog. D. Is definitely a cow because his girlfriend is a cow." Now obviously the answer is going to be debatable and in fact here at the office we had a long debate about what kind of species Goofy is but when you take a look at the question, if you notice the difference between A and B. There's a fuzzifier in C. Right? So A and B are very specific, they're saying definitely a dog or not a dog. C says maybe a mutated dog that talks and Pluto, you know that's irrelevant. D is also a definite kind of a question. So C has a fuzzifier and it has the word "may" and generally speaking when you have a question that has an answer that says "may be" or "may not be," that's usually the correct answer. So sometimes fuzzy answers are the correct ones. Now let's do another one. This is a non-sensical question that strategic students were able to answer correctly 50% of the time. "A 40-year-old, six foot tall yellow bird has a sore back. The following is true: A. The gizzard pulls on the wetback, always resulting in a Kite deformity. B. The gizzard pulls on the wetback, preventing a Kite deformity. C. The gizzard pulls on the wetback, which may result in a Kite deformity. D. The beak is pulling on the wetback, which always results in a Kite deformity." Of course, this question means nothing, it's non-sense but you can see that one of them is like the other. You know, 3 of them are kind of the same.

    03:31 Okay, I won't sing the whole song but you know what I'm getting at. C has a fuzzifier in it, it has the word "may" in it and generally speaking that's going to be the correct answer. The other thing that you want to be aware of is something called double negatives. Sometimes examiners use double negative not necessarily as a trick but just as a means of testing you. An example of this is the term "less lipophilic" to substitute or confuse you with the word "more hydrophobic." It helps to convert terms into 1 term to make it easier to understand. Let me show you what I mean. The hepatic metabolism of most drugs results in the following and choose one. A. The daughter drug is more lipophilic than the parent drug. B. The daughter drug is less lipophilic than the parent drug. C. The daughter drug is more hydrophobic than the parent drug.

    04:26 D. Glucuronidation through a phase 1 process at cytochrome P450. Then there's E. Increased volume of distribution. So when you're looking at this remember that lipophilic is the same as hydrophobic and remember that lipophobic is the same as hydrophilic. Convert the terms into something common. In this case, you know that hepatic metabolism results in drugs that are more hydrophobic. So let's convert the questions into hydrophobic statements. So: A. We're going to take out more lipophilic and convert it into less hydrophilic. B. We're going to convert less lipophilic and convert it into more hydrophilic. With C. We're going to convert more hydrophobic into less hydrophilic. Okay, couple of points. First you can see that now that you've converted the terms, it makes more sense and is easier to understand the question.

    05:31 Second, you notice that A and B are opposite to each other, B and C are opposite to each other and C and A are the same. So right away without knowing anything about lipophilicity and hydrophilicity, you know that it's impossible to have 2 correct answers. Does that make sense? So right away you know A and C have to be wrong without knowing anything about science and you also know that because there is an opposite there, meaning B, that if the wrong answer is wrong then the opposite of the wrong answer must be right. So therefore D and E are actually not useful or not relevant to the question. So let's take a look at the answer. So you can see that A and C are wrong and B is correct. Honestly, there's no trick questions. When we as examiners try to come up with a question, it's actually really hard and what we're trying to do when we make a question is we're trying to test you on a learning point, we're not trying to test you on your ability to understand English and a lot of times we make mistakes making questions and we try not to do that. Remember that if an answer could possibly be true, we try not to put it into the question but in rare circumstances we're not thinking perhaps as complexly as you are and perhaps you're reading into a question a little bit too much. Relax, take a look at a question. If there are 2 potentially correct answers think about what the examiner must be thinking and come up with a more simple answer because that's probably the correct answer. "An 80-year-old male with chronic constipation presents with severe gastroesophageal reflux after a large turkey dinner. The best choice for acute treatment in this individual is: A. Aluminum hydroxide. B. Magnesium oxide. C. Calcium carbonate. D. Sodium bicarbonate. E. Metoclopramide." In this question, it feels like a trick because all of these agents are bowel active agent and could be used. Right? Not quite. This is not a trick. The examiner is trying to isolate one of them from the others to teach you that one of these agents is the best choice in this patient. So let's look at that stem again. This man is 80 years old, he has chronic constipation and has gastroesophageal reflux disease and he has just eaten. Why would the examiner tell you that? Because it's relevant. Listen, relax, you know this. What would you do at home with grandpa if he had 2 problems at the same time and you wanted to give him something to feel better? The answer is magnesium oxide and what the examiner is trying to ask you is this. Aluminum hydroxide which is also known as "Maalox" can be constipating. It's not a great choice in this patient with chronic constipation. Calcium carbonate and sodium bicarbonate are weaker antacids so they're going to treat the acid problem but not the constipation problem. Right? Metoclopramide is a promotility agent so it's going to treat the constipation but not the acid issue. The answer is going to be B, magnesium oxide or Milk of Magnesia which has laxative, antiacid and soothing effects on the elderly bowel. After you've done the Pharmacology lecture, you'll know this answer but also I want to stress the fact that this kind of a question shows that the examiner isn't honestly trying to trick you and you know this information. This is something that you understand but when you're faced with a question it looks a lot harder than it actually is. Okay, let's take those skills that we just learned and let's try narrowing down the choices here to 2 out of the 5 choices.

    09:36 Now, I've blocked part of the answer to the next question so there is no way that you can use your medical knowledge to figure out the answer. You have to use your logic to choose or eliminate half of the choices. Let's look at my computer screen here. "So a 55-year-old male has diabetic enteropathy with poor bowel function. He was placed on domperidone. The following statements are true except." Okay so let's look at the answers. "A. Metoclopramide and domperidone are _____. B. Domperidone crosses the _____. C. Metoclopramide and domperidone may be used in _____. D. Metoclopramide may cause _____." Okay, let's look at the fuzzifiers here. So first of all in terms of the fuzzifiers, C and D have fuzzifiers in them.

    10:29 So these statements are probably true. Now, let's take a look at the question. One of the things that I always do when I write an exam is I either circle or really pay attention to negatives in the question. So look at that, it says: "The following statements are true except." So we're looking for the false statement and we've already established that C and D are true statements so C and D are not the answer here. Therefore, the answer has to be either A or B. Do you follow my logic? Okay, let's look at the answers. So B, we were right, we got 1 out of the 2 just looking at the way that the structure of the question was. So the following statements are true except domperidone crosses the blood brain barrier. So just for your own information and you'll learn this in the Pharmacology lectures, domperidone does not cross the blood brain barrier so it is the incorrect answer in this question and therefore that would be the one that we put down because we have except up in the stem. Right? So that's how we're able to use logic to answer questions.


    About the Lecture

    The lecture Test Taking Strategies for USMLE Step 1 Questions by Pravin Shukle, MD is from the course How to Prepare for USMLE Step 1.


    Author of lecture Test Taking Strategies for USMLE Step 1 Questions

     Pravin Shukle, MD

    Pravin Shukle, MD


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