Percentile Question????

[sexyman]

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Ok so I spoke to someone from Ross who scored a 219 on the USMLE Step I, he said that was roughly 89th percentile. He also said the average of US students score is roughly (sorry for the bad stats) a 217.

My question is if US student average is 217 (50th percentile), how can 219 be 89th percentile? 😱

Are students from other parts of the world "pulling" the scores down that heavy, I am so confused. Where can I get stats on what percentiles students from different schools generally score? I would love to see a chart showing USMLE percentiles of Caribean students, DO students, MD US students, European students etc...

Sorry if this makes no sense, I am just a clueless pre-med studying for the MCAT.

 

[Pinkertinkle]

Because the USMLE stopped publishing percentiles and started their esoteric two digit score system, percentile data is hard to come by. To derive percentiles you'll have to estimate using a normal distribution around the mean of 215 or so with a std dev of 20 or so. Thus a 219 is probably 60thish percentile. 235 is around 85th percentile, 255 97th percentile.

Your friend is confused by the 2 digit score he got. The two digit score is NOT a percentile and pretty much means absolutely nothing, and should just be ignored entirely. It is arbitrary set so that passing score is equal to 75.

 

[njbmd]

Ok so I spoke to someone from Ross who scored a 219 on the USMLE Step I, he said that was roughly 89th percentile. He also said the average of US students score is roughly (sorry for the bad stats) a 217.

My question is if US student average is 217 (50th percentile), how can 219 be 89th percentile? 😱

Are students from other parts of the world "pulling" the scores down that heavy, I am so confused. Where can I get stats on what percentiles students from different schools generally score? I would love to see a chart showing USMLE percentiles of Caribean students, DO students, MD US students, European students etc...

Sorry if this makes no sense, I am just a clueless pre-med studying for the MCAT.

USMLE has a three-digit and a two-digit score. That two-digit score is not a percentile but rather like scoring from 1-100 on a 100-point exam. Whatever the minimum three-digit score, say 183, that score is set to a two-digit score of 75. A three digit score of 200 might be turn out to be a two-digit score of 80. The average score for grads of medical schools in the United States has been around 215-220. The average score for all USMLE test-takers has been around 200 or a two-digit score of around 80. Believe me, a 219 is NOT 89th percentile or even a two-digit score of 89.

In order to figure out the percentiles, you have to know the mean and then calculate from there. In general, if you score anything above 240, your two digit score will be listed as 99. That's the same as scoring 99 out of 100 on a 100-point exam. Some residency program directors are interested in the three-digit score and others are interested in the two-digit score. It doesn't make much difference because both scores are reported on your USMLE transcript.

 

[sexyman]

thanks guys

so if the average US student gets a 215-220, and all test takers is around 200, then non US students do pretty poorly then huh. Cause you have to figure the 215-220 factored into the 200.

 

[Angel Vinuela]

I'm starting to prepare for Step 1. Thanks for all the info about scores. My question is maybe too simple but, is the 3 digit score the number of correct answers?.

 

[PeepshowJohnny]

I'm starting to prepare for Step 1. Thanks for all the info about scores. My question is maybe too simple but, is the 3 digit score the number of correct answers?.

No one's quite sure about what the three digit score is, but no, it's not simply the number of correct answers you get right. It's a function of how many you get right scaled to the difficulty of the version of the tst you took.

 

[blz]

this is standard stuff caribbean students always pull. i have heard the craziest things from my friends in the caribbean. "the highest score ever on the boards was a student from Ross"..."our match list is better than most schools in the US"..."our avg board scores are just as good as US schools"..."attendings in the USA say Ross students do the best during rotations"...the list goes on. whats up with these people. a 219 might be 89%tile among all caribbean takers only, thats about it.

 

[PeepshowJohnny]

this is standard stuff caribbean students always pull. i have heard the craziest things from my friends in the caribbean. "the highest score ever on the boards was a student from Ross"..."our match list is better than most schools in the US"..."our avg board scores are just as good as US schools"..."attendings in the USA say Ross students do the best during rotations"...the list goes on. whats up with these people. a 219 might be 89%tile among all caribbean takers only, thats about it.

I agree with ya blz that Caribbean schools have some indoctrinated students who spout crazy stuff about the boards. However, I've also known plenty of allopathic students who think their two digit score is their percentile.

 

[Phallacious]

There are so many idiots who think the two digit score is a percentile.

The USMLE printout tells you that the mean is roughly a 218 w/ a 23 point standard deviation. Which -for those not having taken stats 101- means that 17% of test takers scored above a 241.

A 235 is closer to 76%.

 

[joe6102]

The USMLE printout tells you that the mean is roughly a 218 w/ a 23 point standard deviation. Which -for those not having taken stats 101- means that 17% of test takers scored above a 241.

Not necessarily. The data is not a normal distribution.

If you really want to know a good approximation of your percentile, google "charting outcomes in the match" and you can figure it out compared to those who went through the match 2 years ago.

 

[Pinkertinkle]

Not necessarily. The data is not a normal distribution.

If you really want to know a good approximation of your percentile, google "charting outcomes in the match" and you can figure it out compared to those who went through the match 2 years ago.

So what's a 245 percentile wise approximately according to your method?

 

[Phallacious]

Not necessarily. The data is not a normal distribution.

If you really want to know a good approximation of your percentile, google "charting outcomes in the match" and you can figure it out compared to those who went through the match 2 years ago.

I went to this site. Very helpful, but still doesn't tell you your PERCENTILE based on your 2 or 3 digit score.

As far as it not being based on a normal distribution, I have no knowledge of this and just assumed it was. Cite you source for assuming it some other kind of distribution.

 

[BlackNDecker]

It is possible to calculate your EXACT percentile!! It's actually very simple and only requires two formulas (I found the formulas in the 2005 Kaplan Biostats review book in their discussion of s.d and mean). I don't recall the exact 2 fromulae(?), but...if you know the mean and the s.d. you can convert to a Z-score and get the EXACT percentile.

Look in a biostats book at z-scores and see what you can come up with.

In 2006, a 253 was the 94th percentile. I think the mean was 216 and the s.d. was 24.

 

[blz]

It is possible to calculate your EXACT percentile!! It's actually very simple and only requires two formulas (I found the formulas in the 2005 Kaplan Biostats review book in their discussion of s.d and mean). I don't recall the exact 2 fromulae(?), but...if you know the mean and the s.d. you can convert to a Z-score and get the EXACT percentile.

Look in a biostats book at z-scores and see what you can come up with.

In 2006, a 253 was the 94th percentile. I think the mean was 216 and the s.d. was 24.

dude...

 

[miss medulla]

ok does 213 / 88 make a descent score? BLZ ,anyone. and please all nasty remarks to a minimum😀 let me be more specific im american IMG interested in internal med or surgery general. please please please someone with some knowledge help a future collegue out.

 

[BlackNDecker]

dude...

Did I miss something here?

ok does 213 / 88 make a descent score? BLZ ,anyone. and please all nasty remarks to a minimum let me be more specific im american IMG interested in internal med or surgery general. please please please someone with some knowledge help a future collegue out.

"Charting outcomes of the match" has all the answers you are looking for.



For further clarification on calculating a %ile, ask someone in the dept. of Biostats at your program. They will be able to guide you in the right direction.

 

[lord_jeebus]

Did I miss something here?

The Z-score would only provide an exact percentile if the score distribution followed a normal distribution, which it doesn't.

 

[BlackNDecker]

The Z-score would only provide an exact percentile if the score distribution followed a normal distribution, which it doesn't.

How could you possibly know whether the score distribution is normal or not?

 

[lord_jeebus]

How could you possibly know whether the score distribution is normal or not?

I've seen a graph of national score distribution. Although it's a bar graph and lumps the scores into levels, it is not consistent with a normal distribution.

The Z-score is probably a good rough estimate of actual percentile.

 

[miss medulla]

i went to the link.... it just gives some curve. i just need some general opinions here .please anyone any comments again my score was 213 / 88 . is this a solid score to get into internal med?

 

[Pinkertinkle]

i went to the link.... it just gives some curve. i just need some general opinions here .please anyone any comments again my score was 213 / 88 . is this a solid score to get into internal med?

I'd say thats probably somewhere between 45th and 50th percentile. Should be fine for IM as long as you don't care where.

 

[lunartune]

To Lord Jeebus and Black n Decker:

If it was a normal distribution:

mean = 218
SD = 23

241: ~84 percentile
264: ~97.5 percentile
287: ~99.85 percentile

I doubt someone ever scored higher than 275 or 280. And 2.5% scored above 264? Maybe. To me the curve seems compressed at least in the 'high score range' (maybe above 250-255).

lt

 

[miss medulla]

Thanks PINKIE!

Lunartune its about time u got out of that step1 forum 😀 were moving on honey.....

as far as the curves........hey lets not beat a dead horse here

 

[joe6102]

So what's a 245 percentile wise approximately according to your method?

If you know what specialty you want to go into, you can calculate your percentile reltavie to people who matched into that specialty last year. As for the overall percentile, I think the best way is to look at the scores for Internal Medicine. That is a large sample size that closely reflects all applicants at the 25th percentile, mean, and 75th percentile. (It would take forever, but you could add up all of the numbers for all of the specialties and get a closer approximation. Keep in mind this still would not include the early match.)
http://www.nrmp.org/data/chartingoutcomes2007.pdf

6885 total applicants with scores available:

score: percentile
181: 0.9
191: 11.8
201: 25.7
211: 40.9
221: 58.0
231: 73.7
241: 86.6
251: 95.0
261: 99.0

 

[miss medulla]

thanks joejoe!

 

[Pinkertinkle]

If you know what specialty you want to go into, you can calculate your percentile reltavie to people who matched into that specialty last year. As for the overall percentile, I think the best way is to look at the scores for Internal Medicine. That is a large sample size that closely reflects all applicants at the 25th percentile, mean, and 75th percentile. (It would take forever, but you could add up all of the numbers for all of the specialties and get a closer approximation. Keep in mind this still would not include the early match.)
http://www.nrmp.org/data/chartingoutcomes2007.pdf

6885 total applicants with scores available:

score: percentile
181: 0.9
191: 11.8
201: 25.7
211: 40.9
221: 58.0
231: 73.7
241: 86.6
251: 95.0
261: 99.0

Yes that's very reasonable. I approve of this method.