First Aid for the USMLE Step 2 CK 6th edition eBook
TABLE OF CONTENTS
Contributing Authors vii
Faculty Reviewers ix
How to Contribute xv
SECTION 1 GUIDE TO E FFICIENT EXAM PREPARATION 1
USMLE Step 2 CK—Computer-Based Testing Basics 2
Defining Your Goal 8
Study Resources 10
Test-Day Checklist 12
Testing Agencies 12
SECTION 1 SUPPLEMENT SPECIAL SITUATIONS 13
First Aid for the International Medical Graduate 14
First Aid for the Student with a Disability 35
SECTION 2 DATABASE OF H IGH-YIELD FACTS 37
How to Use the Database 38
Ethics and Legal Issues 133
Infectious Disease 203
For more information about this title, click here
Selected Topics in Emergency Medicine 451
Rapid Review 467
SECTION 3 TOP-RATED REVIEW RESOURCES 493
How to Use the Database 495
Online Comprehensive Review 502
Internal Medicine 503
Commercial Review Courses 530
Appendix: Abbreviations and Symbols 531
About the Authors 559
The United States Medical Licensing Examination (USMLE) Step 2 allows
you to pull together your clinical experience on the wards with the numerous
“factoids” and classical disease presentations that you have memorized over
the years. Whereas Step 1 stresses basic disease mechanisms and principles,
Step 2 places more emphasis on clinical diagnosis and management, disease
pathogenesis, and preventive medicine.
The Step 2 exam is now composed of two parts:
■ The Step 2 Clinical Knowledge examination (Step 2 CK)
■ The Step 2 Clinical Skills examination (Step 2 CS)
The USMLE Step 2 CK is the second of three examinations that you must
pass in order to become a licensed physician in the United States. The computerized
Step 2 CK is a one-day (nine-hour) multiple-choice exam.
Students are also required to take the Step 2 CS, which is a one-day live
exam in which students examine 12 standardized patients. The goal of the
Step 2 CS is to ensure that students from more than 1600 medical schools
worldwide, with varying curricula and educational standards, can collect and
interpret a history, perform a physical exam, and communicate with patients
at a comparable level. For more information on this examination, please refer
to First Aid for the USMLE Step 2 CS. Information about the Step 2 CS format
and about eligibility, registration, and scoring can be found at
The information found in this section as well as in the remainder of the
book will address only the Step 2 CK.
USMLE STEP 2 CK—COMPUTER-BASED TESTING BASICS
How Will the CBT Be Structured?
The Step 2 CK is a computer-based test (CBT) administered by Prometric,
Inc. It is a one-day exam with 368 questions divided into eight 60-minute
blocks of 46 questions each. A new form of testing software called FRED is
now being used by the USMLE. FRED is different from the Step 1 exam you
took in that you can now highlight and strike out test choices as well as make
brief notes to yourself. During the time allotted for each block, the examinee
can answer test questions in any order as well as review responses and change
answers just as in the Step 1 exam—but examinees cannot go back and
change answers from previous blocks. Once an examinee finishes a block, he
or she must click on a screen icon to continue to the next block. Time not
used during a testing block will be added to your overall break time, but it
cannot be used to complete other testing blocks. Expect to spend up to nine
hours at the test center.
Testing Conditions: What Will the CBT Be Like?
Even if you’re familiar with CBT and the Prometric test centers, FRED is a
new testing format that you should access from the USMLE CD-ROM or
Web site (www.usmle.org) and try out prior to the exam.
If you familiarize yourself with the FRED testing interface ahead of time,
you can skip the 15-minute tutorial offered on exam day and add those minutes
to your allotted break time of 45 minutes.
The goal of the Step 2 CK is to
apply your knowledge of
medical facts to clinical
scenarios you may encounter
as a resident.
GUIDE TO E FFICIENT EXAM PREPARATION
For security reasons, examinees are not allowed to bring personal electronic
equipment into the testing area—which means that digital watches,
watches with computer communication and/or memory capability, cellular
telephones, and electronic paging devices are all prohibited. Food and beverages
are prohibited as well. Examinees are given laminated writing surfaces
for note taking, but these must be returned after the examination. The testing
centers are monitored by audio and video surveillance equipment.
You should become familiar with a typical question screen (see Figure
1-1). A window to the left displays all the questions in the block and shows you
the unanswered questions (marked with an “i”). Some questions will contain
figures or color illustrations adjacent to the question. Although the contrast
and brightness of the screen can be adjusted, there are no other ways to manipulate
the picture (e.g., zooming, panning). Larger images are accessed
with an “exhibit” button. The examinee can also call up a window displaying
normal lab values. You may mark questions to review at a later time by clicking
the check mark at the top of the screen. The annotation feature functions
like the provided erasable dry boards and allows you to jot down notes during
F I G U R E 1 – 1 . Typical FRED Question Screen
GUIDE TO E FFICIENT EXAM PREPARATION 4
the exam. Play with the highlighting/strike-out and annotation feature with
the vignettes and multiple answers.
You should also do a few practice blocks to get a feel for which tools actually
help you process questions more efficiently and accurately. If you find
that you are not using the marking, annotation, or highlighting tools, then
keyboard shortcuts can save you time over using a mouse.
What Does the CBT Format Mean for Me?
The CBT format is the same format as that of the USMLE Step 1. If you are
uncomfortable with this testing format, spend some time playing with a Windows-
based system and pointing and clicking icons or buttons with a mouse.
The USMLE also offers an opportunity to take a simulated test, or practice
session, at a Prometric center. The session is divided into three one-hour
blocks of 50 test items each. The USMLE Step 2 CK sample test items (150
questions) that are available on the CD-ROM or on the USMLE Web site
(www.usmle.org) are the same as those used at CBT practice sessions. No
new items will be presented. The cost is about $42 for U.S. and Canadian
students but is higher for international students. The student receives a
printed percent-correct score after completing the session. No explanations of
questions are provided. You may register for a practice session online at
How Do I Register to Take the Exam?
Information on Step 2 CK format, content, and registration requirements can
be found on the USMLE Web site. To register for the exam in the United
States and Canada, apply online at the National Board of Medical Examiners
(NBME) Web site (www.nbme.org). A printable version of the application is
also available on this site.
The preliminary registration process for the USMLE Step 2 CK is as follows:
■ Complete a registration form and send examination fees to the NBME
■ Select a three-month block in which you wish to be tested (e.g.,
■ Attach a passport-type photo to your completed application form.
■ Complete a Certification of Identification and Authorization Form. This
must be signed by an official at your medical school (e.g., the registrar’s office)
to verify your identity. This is a new form and is valid for five years, allowing
you to use only your USMLE identification number for future
■ Send your certified application form to the NMBE for processing. (Applications
may be submitted more than six months before the test date, but
examinees will not receive their scheduling permits until six months prior
to the eligibility period.)
■ The NBME will process your application within four to six weeks and will
send you a fluorescent orange slip of paper that will serve as your scheduling
■ Once you have received your orange scheduling permit, decide when and
where you would like to take the exam. For a list of Prometric locations
nearest you, visit www.prometric.com.
Enter or Spacebar—Move to
Esc—Exit pop-up Lab and
for current session and
GUIDE TO E FFIC IENT EXAM PREPARATION
■ Call Prometric’s toll-free number or visit www.prometric.com to arrange a
time to take the exam.
■ The Step 2 CK is offered on a year-round basis except for the first two
weeks in January. For the most up-to-date information on available testing
days at your preferred testing location, refer to www.usmle.org.
Your orange scheduling permit will contain the following important information:
■ Your USMLE identification number
■ The eligibility period in which you may take the exam
■ Your “scheduling number,” which you will need to make your exam appointment
■ Your candidate identification number, or CIN, which you must enter at
your Prometric workstation in order to access the exam
Prometric has no access to the codes and will not be able to supply these
numbers. Do not lose your permit! You will not be allowed to take the Step 2
CK unless you present your permit along with an unexpired, governmentissued
photo identification that contains your signature (e.g., driver’s license,
passport). Make sure the name on your photo ID exactly matches the name
that appears on your scheduling permit.
What If I Need to Reschedule the Exam?
You can change your date and/or center within your three-month period without
charge by contacting Prometric. If space is available, you may reschedule
up to five days before your test date. If you need to reschedule outside your
initial three-month period, you can apply for a single three-month extension
(e.g., April/May/June can be extended through July/August/September) after
your eligibility period has begun (visit www.nbme.org for more information).
This extension currently costs $50. For other rescheduling needs, you must
submit a new application along with another application fee.
What About Time?
Time is of special interest on the CBT exam. Here is a breakdown of the
Tutorial 15 minutes
60-minute question blocks (46 questions per block) 8 hours
Break time (includes time for lunch) 45 minutes
Total test time 9 hours
The computer will keep track of how much time has elapsed during the
exam. However, the computer will show you only how much time you have
remaining in a given block. Therefore, it is up to you to determine if you are
pacing yourself properly.
The computer will not warn you if you are spending more than the 45
minutes allotted for break time. However, you can elect not to use all of your
break time, or you can gain extra break time either by skipping the tutorial or
by finishing a block ahead of the allotted time.
Because the exam is
scheduled on a “first-come,
first-served” basis, you should
be sure to call Prometric as
soon as you receive your
GUIDE TO E FFICIENT EXAM PREPARATION 6
If I Leave During the Exam, What Happens to My Score?
You are considered to have started the exam once you have entered your CIN
onto the computer screen. In order to receive an official score, you must finish
the entire exam. This means that you must start and either finish or run
out of time for each block of the exam. If you do not complete all the blocks,
your exam will be documented on your USMLE score transcript as an incomplete
attempt, but no actual score will be reported.
The exam ends when all blocks have been completed or time has expired.
As you leave the testing center, you will receive a written test-completion notice
to document your completion of the exam.
What Types of Questions Are Asked?
■ Almost all questions on the Step 2 CK are case based. A substantial
amount of extraneous information may be given, or a clinical scenario
may be followed by a question that could be answered without actually requiring
that you read the case. It is your job to determine which information
is superfluous and which is pertinent to the case at hand.
■ Subject areas vary randomly from question to question.
■ Most questions have a single best answer, but some matching sets call for
multiple responses (the number to select will be specified). The part of the
vignette that actually asks the question—the stem—is usually found at the
end of the scenario. From student experience, there are a few stems that
are consistently addressed throughout the exam:
■ What is the most likely diagnosis? (40%)
■ Which of the following is the most appropriate initial step in management?
■ Which of the following is the most appropriate next step in management?
■ Which of the following is the most likely cause of . . . ? (5%)
■ Which of the following is the most likely pathogen . . . ? (3%)
■ Which of the following would most likely prevent . . . ? (2%)
■ Other (10%)
■ Note the age and race of the patient in each clinical scenario. When ethnicity
is given, it is often relevant. Know these well (see high-yield facts),
especially for more common diagnoses.
■ Be able to recognize key facts that distinguish major diagnoses.
■ Questions often describe clinical findings instead of naming eponyms
(e.g., they cite “audible hip click” instead of “positive Ortolani’s sign”).
■ Questions about acute patient management (e.g., trauma) in an emergency
setting are common.
The cruel reality of the Step 2 CK is that no matter how much you study,
there will still be questions you will not be able to answer with confidence. If
you recognize that a question is not solvable in a reasonable period of time,
make an educated guess and move on; you will not be penalized for guessing.
Also keep in mind that 10–20% of the USMLE exam questions are “experimental”
and will not count toward your score.
How Long Will I Have to Wait Before I Get My Scores?
The USMLE reports scores three to four weeks after the examinee’s test date.
During peak times, however, reports may take up to six weeks to be scored.
GUIDE TO E FFIC IENT EXAM PREPARATION
Official information concerning the time required for score reporting is
posted on the USMLE Web site, www.usmle.org.
How Are the Scores Reported?
Like the Step 1 score report, your Step 2 CK report includes your pass/fail status,
two numeric scores, and a performance profile organized by discipline
and disease process (see Figures 1-2A and 1-2B). The first score is a three-digit
scaled score based on a predefined proficiency standard. In 2006, the required
passing score was 182, which required answering 60–70% of questions correctly.
The second score scale, the two-digit score, defines 75 as the minimum
passing score (equivalent to a score of 182 on the first scale). This score is not
a percentile. Any adjustments in the required passing score will be available
on the USMLE Web site.