Differences between NBME vs USMLE Test ?

The NBME (National Board Of Medical Examiners) Test forms are a series of 4 block tests conducted at a cost of $60 to test USMLE exam readiness for potential examinees. The score received on the NBME forms is highly predictive of the real exam and is a good metric to gauge how well is your preparation. While the NBME is a good proxy to the USMLE score and is a must-do for USMLE preparation, there are certain differences that one should be aware of. I have in the past written an article on How to Best Use the NBME ? In this article I highlight those differences which are frequently overlooked by many. Being aware of these differences will better prepare you for what’s in store for exam day. Additionally every potential issue is followed by a solution to help you test yourself in an environment that best emulates a real exam:

Setup of the Test

The NBME tests are given at your home, in a familiar surrounding. You have a fridge full of your favorite food, can get up and grab a snack while giving the test and are in a comfortable surrounding. You can keep your feet up on the table and give the exam as you please all while checking your favourite cat photo pages on Facebook.

This changes completely in the USMLE Prometric exam center. Instead of being at ease, you are constantly forced to do a security check, patted down, fingerprint scanned and signed entry and exit. All of this adds to the high pressure situation and is uncomfortable.

We perform best when the situation is under our control. When we give the exam in the Prometric center, the same brain which performed well at home is under an immense amount of stress. Stress that may be caused by having to travel out of town, given an exam under unfamiliar surroundings, carrying documentations, and taking the test under strict security. In addition to this, if i may share my own experience, i was giving the test along with examinees who needed to type for their exam (like the GMAT, IELTS, etc). Their noise disturbed me a lot. In addition to this i had to tolerate the constant sniffing and coughing of a girl giving the test next to me. All of this lead to unnecessary irritation and distraction.

SOLUTION:

Because the real test was not a very comfortable experience, i made sure i emulate this. I took 2 NBME tests back to back every time i gave a mock test. I considered my score as a mean of the 2 tests. I have a little sister who plays with toys, i asked her to be in the room while i gave the NBME tests. In addition to emulating the noise distractions, i also prepared a small snacks packet including a sandwich and chips and 2 Red Bulls. I gave the exam with the snack pack on a table next to me. After every block i would get up and take a break if i wanted to. I would time my breaks and make sure that i don’t take more than the alloted time. This method of testing in uncomfortable situations helped me simulate the real exam environment

Length of the Exam

The real exam is 7 blocks whereas the NBME is only 4 hours in length. While the vast majority of people take only 1 NBME a day, this overestimates our performance. The reason is : In the early hours of a test we are fresh and perform better. However after 7 hours in an 8 hour exam, our brain starts to fatigue out and hence a 4 hour test is not rigorous enough to emulate a 8 hour test.

SOLUTION:

As alluded to previously, i took 2 NBME tests back to back in order to emulate a real testing environment. This was actually very helpful as i usually scored lesser in my second NBME as compared to my first one. I would take the average of the 2 tests as my mock test score.

Length of questions

The NBME questions are notoriously short. This is not the case with the real exam. While in most NBME tests, the questions are direct and to the point, in the real exam questions are filled with tons of labs which do not necessarily have anything to do with question but are kept in there to confuse you and use up your time. (NBME Lab Values are provided in every NBME just like USMLE Step 1 provides Lab Values)

SOLUTION:

The Uworld questions are of a similar length as the actual exam and since most people are going to do UWorld not once but multiple times, we already have decent practice with longer question formats. One extra tip i used to decrease time spent to solve a question and make longer questions easier is to not use the UWorld or NBME labs value button and instead memorize ALL the normal lab values. Following is a list of the lab values which you need to memorize for Step 1 , Step 2 as well as the for the clinics in the future when you are in a residency. Make sure you memorize these. The NBME lab values are same as the USMLE Step 1 Lab Values. Following is a list of the lab values which you can access from every NBME:

USMLE Step 1 Lab Values

USMLE Step 1 Lab Values/ NBME Lab Values

USMLE Step 1 Lab Values

USMLE Step 1 Lab Values/ NBME Lab Values

Media Questions

The real exam has a lot of media items which are not on the question sets of the NBME. For example, there are no 12 Lead ECGs on the NBME tests. There are only Single (1 lead) ECGs in the NBME tests. In a 12 lead ECG we have to pick out an aberrant finding from all the leads. The NBME forms have ECG questions with just 1 lead in the question. This makes the questions incredibly easy and hence are not a good proxy to the actual USMLE because the real USMLE has multiple questions with 12 lead ECGs. For example, you may encounter a practice question in an NBME of a single lead ECGs like an ECG segment with a clear cut T wave elevation (for hyperkalemia) [SEE IMAGE BELOW].

Single Lead ECG

Single Lead ECG

Now this is incredibly easy to diagnose as your options are narrowed down to just one lead. Had the question been a 12 lead ECG the difficulty level would have been very high. I recommend you practice 12 lead ECGs [Like the Below Image] to emulate the real exam scenario.

 

12 Lead ECG

12 Lead ECG

Also, the heart sounds in the real exam are not like those in UWorld or NBME and don’t have a simple, single play button. Instead they have different auscultation sites [AS SHOWN IN IMAGE] and then it is on you to find out where the abnormal sound is located.
The reason this is important to note is that the heart sounds you practice will have a simple play button with the abnormal area already given to you. This narrows down the choices sometimes to just 2-3 diseases and doing such questions will create a false feeling of being good at these diagnoses. However, the reality is that the questions on heart sounds in the practice tests like UWorld and NBME are MUCH MUCH easier than the real exam and hence
For example, having a single button which says, Apex area sound is as follows decreases the difficulty level a lot in the NBME questions. But  many people find it very tough and frustrating while trying to diagnose a multiple site heart auscultation in the real exam. Following is how the heart sounds are to be diagnosed in the real test (excerpt from Official USMLE Practice Materials):

Heart Sounds & Murmurs

Heart Sounds & Murmurs

Note that there are multiple auscultation zones and diagnosing the above scenario should be practiced many times before the real exam.

CONCLUSION

While the NBME forms are the closest you can get to the actual USMLE exam style and scenario, it is worth keeping in mind the differences between the 2. These differences may prove to be much bigger problems than anticipated, if not mitigated in advance. A lot of your USMLE score will depend not on your preparation but on your test day performance. I would suggest you keep this page bookmarked to refer to later. It will definitely payoff to have these in mind.

This highlights the differences between NBME vs USMLE. If you found this informational, I recommend you check out my article outlining how to use the NBME forms effectively to score well on your USMLE Step 1 exam.
September 30, 2017
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