COMLEX to USMLE Conversion: Insights for Osteopathic Medical Students

Aspiring physicians who hope to practice in the United States undergo a comprehensive examination process to become eligible for residency programs. The two prominent licensing exams for medical students are the Comprehensive Osteopathic Medical Licensing Examination (COMLEX) and the United States Medical Licensing Examination (USMLE). Generally, osteopathic (DO) students take the COMLEX, and allopathic (MD) students take the USMLE. However, many DO students will take both COMLEX and USMLE examinations to strengthen their application to more competitive residency programs that historically prefer the USMLE score. In this blog, we will focus on the differences and similarities between these exams, whether conversion between your COMLEX to USMLE scores can serve as a good predictor for success on either exam and more!

Both COMLEX and USMLE are divided into three tests. COMLEX Level 1 and USMLE Step 1 primarily focus on the basic science of medicine. COMLEX Level 2 and USMLE Step 2 primarily focus on the clinical science and practice of medicine. And COMLEX Leve 3 and USMLE Step 3 are the last exams in the series, typically taken during residency, are used to determine whether doctors can provide unsupervised patient care.

Switch to Pass/Fail Grading on COMLEX Level 1 and USMLE Step 1

Recently, COMLEX Level 1 and USMLE Step 1 have transitioned to a strictly pass-fail scoring system where students are not provided a numerical score on their performance. As a result, more emphasis has been placed on the score students receive on COMLEX Level 2 and USMLE Step 2 as it is a tool for which to compare and screen students in the residency process. While these exams assess students’ clinical knowledge and skills, they differ in terms of focus, content, and scoring methods.

In recent years, there has been increasing interest in exploring the correlation between COMLEX Level 2 scores and USMLE Step 2 scores. Many students who take are interested in knowing whether COMLEX to USMLE conversion of scores serves as a good predictor of performance on your next exam. Thus, this blog post aims to delve into this topic. We will shed light on the significance of both exams in the residency process, examining relevant research studies, and helping you convert and predict a potential score on USMLE Step 2, given your COMLEX Level 2 score, or vice versa.

COMLEX Level 2 and USMLE Step 2: The Differences, The Similarities and Everything Between

The COMLEX Level 2 and USMLE Step 2 are comprehensive exams that evaluate a medical student’s ability to apply medical knowledge and skills in a clinical setting. These exams play a crucial role in determining a student’s readiness for residency training and are commonly used as a tool to select and screen residency applicants, especially since Level 1 and Step 1 are now pass/fail.

COMLEX Level 2:

The COMLEX Level 2 was recently changed to a one-part examination administered to osteopathic medical students. It is now known as COMLEX Level 2 Cognitive Evaluation (CE), which focuses on clinical decision-making and medical knowledge. The COMLEX Level 2 CE score is reported as a three-digit number ranging from 100 to 900, with a passing score set at 400 (approximately the 5th percentile). The average COMLEX Level 2 CE score is around 560 but varies widely depending on which specialty students apply to.

A passing COMLEX Level 2 score is generally a graduation requirement for osteopathic students and is accepted by many residency programs across the country; however, many residency programs prefer to have a USMLE score. Because of this, many DO students choose to also take the USMLE exams, and look for ways to calculate conversion from COMLEX to USMLE scores. See our COMLEX Level 2 study schedule for help juggling studying for both of these exams.

USMLE Step 2:

The USMLE Step 2 was recently changed to a one-component examination, similar to COMLEX Level 2, which just consists of a Clinical Knowledge (CK) section. Similarly to COMLEX Level 1, Step 2 CK evaluates medical knowledge and clinical decision-making through a multiple-choice examination. The Step 2 CK score is reported as a three-digit number ranging from 1 to 300, with a passing score varying from year to year. At the time of this blog post, the passing score is 214. More recently, the average USMLE Step 2 score was 246, but what is considered a “good” score similarly depends on which specialty students apply to. The USMLE is designed for both DO and MD students and is widely accepted by residency programs across the country. For DO students, a passing USMLE Step 2 score is not often a graduation requirement, while it traditionally is for MD students.

Significance of COMLEX Level 2 and USMLE Step 2 in the Residency Process

Residency program directors consider COMLEX Level 2 and USMLE Step 2 scores as important factors in assessing a candidate’s clinical competence. However, there are many other components to the residency application process, including shelf examinations, clinical comments, preclinical grades, activities, personal statements, and awards, among others. However, these scores provide a standardized measure of medical knowledge and skills which allows program directors to compare applicants from different institutions. High scores can enhance an applicant’s chances of securing interviews and ultimately obtaining a desired residency position. Given the ever-increasing number of residency applications being submitted each year, program directors can use COMLEX or USMLE scores as one tool, along with others, to help sort through applicants.

COMLEX to USMLE Conversion: Tools to Convert Your COMLEX Level 2 Score to a USMLE Step 2 Score, or Vice Versa

Before we dive into the literature, we must state that we believe there is no rigorously tested formula designed for the conversion of a COMLEX Level 2 score to a USMLE Step 2 score. However, there is a clear correlation between students who score well on the COMLEX and USMLE for both Level 1 and Level 2. This data is not too surprising; those who do well on COMLEX also tend to do well on USMLE as they are similar examinations. However, many students who take one test want to predict how they will do on the other. Can COMLEX Level 2 serve as an accurate predictor for your USMLE Step 2 score, and vice versa? We will review two recently published studies to try and help you understand how your performance on COMLEX Level 2 can inform how you may perform on USMLE Step 2, and vice versa.

A Concordance Study of COMLEX-USA and USMLE Scores, Barnum et al., J Grad Med Educ, 2022

• Data: Obtained data from five osteopathic medical schools across the United States from 2015-2020 on 1468 students who took both COMLEX Level 2 and USMLE Step 2. 
• Findings:
  • The average time between taking COMLEX Level 2 and USMLE Step 2: 12 Days (SD = 18)
  • 48% of students take COMLEX Level 2 before USMLE Step 2
  • Table showing the correlation between students’ COMLEX scores and USMLE Step 2 scores (Fig. 1 below)
  • Raw data plotting students’ COMLEX Level 2 score vs. USMLE Step 2 score (Fig. 2 below)
• Conclusions:
  • From this manuscript, you can use the table for USMLE to COMLEX conversion. Find your COMLEX Level 2 score or USMLE Step 2 score and see what students with that score received on the other test.

Predicting Osteopathic Medical Student Performance on the United States Medical Licensing Examination Step 2 Clinical Knowledge From Results of the Comprehensive Osteopathic Medical Licensing Examination Level 2-Cognitive Evaluation, Smith et al., Cureus

• Data: 340 students who took both COMLEX Level 2 and USMLE Step 2 at Lake Erie College of Osteopathic Medicine between May 2020 and April 2021. 
• Findings:
  • For every 1-point increase in the COMLEX Level 2 score, there was an associated 0.13-point increase in USMLE Step 2 score (R^2 = 0.64)
  • Raw data showing the Level 2 and Step 2 scores of the students included in this study
  • If you want to convert your COMLEX Level 2 score to USMLE Step 2 score, you can use the following formula
• USMLE Step 2 Score = 0.13(COMLEX Level 2 score) + 163.5 

Now, if we use the formula in the study by Smith et al. to create a similar table to one found in the study by Barnum et al., we arrive at the following table for USMLE to COMLEX score conversion:

You may notice that the two studies have concordance starting at 540; however, they report quite different USMLE Step 2 scores from COMLEX Level 2 scores ranging from 9-539.

COMLEX to USMLE Conversion Studies Implications and Recommendations for Students:

The aforementioned research studies offer valuable insights for DO students preparing for both the COMLEX Level 2 and USMLE Step 2 exams. While the correlation between scores suggests some predictability, it is important to remember that these studies have many limitations, including small sample size, limited generalizability due to the makeup of the data set, and inability to demonstrate causality, among others. However, both of these studies demonstrate that students who do better on COMLEX Level 2 tend to do better on USMLE Step 2. We argue that the study by Barnum et al., is more rigorous, given the significantly larger sample size and use of multiple osteopathic institutions. However, the results from Smith et al., even with limited sample size and single institution, do show similar overall trends in concordance between COMLEX and USMLE scores.

Ultimately, students should approach each exam independently and prepare adequately.

General Recommendations for Your Preparation:

• Understand the similarities and differences in exam formats: Familiarize yourself with the structure, content, and scoring of both exams. Knowing the exam format will help you tailor your study guide and approach accordingly.
• Develop a comprehensive study plan: Allocate sufficient time for preparation, taking into account the different focuses of each examination. Utilize available resources, like question banks, review books, and practice exams, to enhance your knowledge and test-taking skills.
• Practice time management and balance work/life: Develop effective time management strategies to ensure efficient use of study time. However, also create a study schedule that allows for regular breaks, relaxation, and self-care – while this test is important, you can only reach your maximum potential if you are feeling good and have the motivation to prepare!
• Strengthen clinical reasoning skills: Both of these exams assess clinical decision-making skills. Focus on developing strong clinical reasoning abilities by practicing case-based questions and applying your knowledge to real-world scenarios. The more you can relate your questions to the actual practice of medicine, the more you will understand the importance of the material (and hopefully, it will stick!).
• Seek guidance from others: Consult with academic advisors or tutors who have experience with these examinations, medical school, and the residency application process. They can provide valuable insights and guidance specific to your situation. It is never too early to reach out for help – and getting assistance from someone else can help you be more efficient with your time and effort.

COMLEX to USMLE Conversion: Conclusions

The COMLEX Level 2 and USMLE Step 2 exams are crucial milestones in the journey toward becoming a physician. While each exam has its own distinct characteristics, there is strong research demonstrating a correlation between COMLEX Level 2 and USMLE Step 2 scores. Here, we provide some recent literature to help you understand how your performance on one test can help you predict your score on the other. However, it is critical to remember that individual performance may vary, and caution should be exercised when making predictions based on either score alone! Every student is different, and your outcome may not be similar to the data presented above. With thorough preparation, a comprehensive study plan, and assistance from others, you can maximize your chance of achieving outstanding scores on both the COMLEX Level 2 and USMLE Step 2, opening doors to a successful residency application process. Best of luck!