Biostatistics
For USMLE Step 2 CK and shelf exams

Understand the difference. Make it stick.

Authors of Thieme’s A-WIN review · Academic hospitalists

See the clues that decide each answer, with physician-written explanations, comparison tables, next-step algorithms and images. Then spaced review and your exam-day plan bring it back right up to test day.

Biostatistics is live. Cardiology is next.
Founding offer: the first 500 students who get every chapter free as it’s released.

Medical students in a hospital corridor
New

Your exam-day plan

Set your exam date, and every review is planned to land before it.

  1. 1

    A clear next step each day

    Start with today’s scheduled reviews, then learn new questions. Extra reviews are optional, and you can browse topics whenever you want.

  2. 2

    Reviews that tighten as the exam nears

    Gaps grow as a question earns stars, but never past half the study days left, so close to the exam reviews come every few days.

  3. 3

    A final check, weakest first

    The final check revisits earlier questions, weakest first, with time reserved for follow-up reviews. Coverage depends on when you start and how often you study. Your last 2 days are kept free.

  4. 4

    “Needs refresh” flags

    Miss a mastered question and it’s flagged and back the next day. Two sure, right answers make it mastered again.

Illustrative example, not real user data.

How Pradis works

Use Pradis alongside your Qbank: work through the confusing distinctions, then come back to them until they stick.

What you learn with

Understand the differences

Most questions turn on telling apart similar choices. Side-by-side tables show what separates them.

Remember the hard parts

Mnemonics, tables and flowcharts that make complex material easier to recall.

Learn what’s current

Each chapter is reviewed against current US guidelines before release.

Spaced review

How spaced review works

Every question you answer goes into your review schedule automatically. Here’s what happens next.

  1. Answer a question. Tap Submit and read the explanation. After two correct spaced answers, you can choose “I’m confident” to skip further regular reviews.
  2. Earn three stars. A sure, correct answer at a scheduled review earns a star: your first answer, 5 days later, and about 3 weeks after that (sooner when your exam is close, or when you review ahead). Three stars and the question is mastered. In table questions, each row earns its own stars.
  3. Miss it, and it comes back. A wrong answer starts the question over and brings it back tomorrow. Correct answers earn stars at spaced reviews. After two, you can choose “I’m confident” to skip further regular reviews.
  4. Review what’s due. Your review list shows today’s questions, up to your daily limit (30 to start, and you can change it). Done early? Keep going with the rest that’s due, then with the next days’ reviews. Only questions whose correct answer can count are offered ahead: at least 4 days after their last counted answer. Once every item in a chapter has been seen, you can also keep practising without a session limit; early correct answers leave stars unchanged. Answering early anywhere else doesn’t earn a star.
  5. Get one reminder. If reviews pile up and you haven’t studied for a day, we send one short email. Never more than one a day, and you can turn them off in one click.
  6. Set your exam date. Reviews are spaced to fit before it. Mastered questions come back now and then to stay fresh, and before the exam a final check brings your questions back, weakest first. The last 2 days before your exam are kept free.
☆☆☆→★☆☆→★★☆→★★★

First answer · 5 days later · About 3 weeks after that

Three stars mark a review milestone, not exam readiness. If you miss a mastered question later, it’s marked ‘Needs refresh’ and comes back for two quick checks.

Simple pricing

One plan. Everything you need to study smarter.

Freenow, and for 12 months after launch, for the first 500 members
Founding member offer

Free now, plus 12 months after launch

Limited to the first 500 members who claim a spot. No card needed. Every chapter is yours free as it’s released. When the last chapter is out (that’s launch), your free year starts. After that, $25/month.

  • Every chapter as it’s released, with an explanation for each question
  • Tables, flowcharts and mnemonics built for the exam format
  • Spaced review to three stars, planned around your exam date
  • A reminder email if reviews pile up, at most one a day
  • Progress by chapter and topic: mastered, needs refresh and due today
  • Each chapter reviewed against current US guidelines before release

Not sure yet? Practice Biostatistics free, no account needed.

Chapter roadmap

Every chapter, as it is released.

We aim to release a new chapter every two weeks after review. 1 of 25 chapters is live.

Available

Next

  • CardiologyNext

Planned

  • PulmonologyPlanned
  • GastroenterologyPlanned
  • NephrologyPlanned
  • Acid Base DisordersPlanned
  • Infectious DiseasePlanned
  • EndocrinologyPlanned
  • HematologyPlanned
  • Preventive MedicinePlanned
  • NeurologyPlanned
  • RheumatologyPlanned
  • Allergy and ImmunologyPlanned
  • DermatologyPlanned
  • Emergency MedicinePlanned
  • OphthalmologyPlanned
  • Ear, Nose and ThroatPlanned
  • EthicsPlanned
  • Disorders of Sexual DevelopmentPlanned
  • ObstetricsPlanned
  • GynecologyPlanned
  • Male ReproductionPlanned
  • PediatricsPlanned
  • PsychiatryPlanned
  • General SurgeryPlanned
The authors

Meet our team

Medicine is an art. Learn it like one.

Manoj Gurung, MD

Co-author of A-WIN and creator of Pradis

Assistant Professor of Medicine, Warren Alpert Medical School of Brown University

Academic hospitalist, Kent Hospital, Rhode Island

Yayra Musabek, MD

Co-author of A-WIN and creator of Pradis

Assistant Professor of Medicine, Warren Alpert Medical School of Brown University

Academic hospitalist, Kent Hospital, Rhode Island

A WIN for USMLE Step 2 and 3 CK book cover
The book

The book behind Pradis: a compact Step 2 CK review

The authors wrote A-WIN as a short, practical review for Step 2 CK. It leans on comparison tables, flowcharts and mnemonics to make similar conditions easier to tell apart, and it comes with a digital copy on medone.thieme.com.

The book contains about 600 tables, flowcharts and mnemonics.

Get the book from Thieme →Get the book on Amazon →
Reviews of the book

What readers say about A-WIN

…the use of tables is very beneficial in these chapters. It allows the reader to easily compare and contrast differing pathologies, and seeing important differences in presentations, labs, etc.…
Anita S. · Medical student · review of the book
…Important and highly tested points are emphasized, pathologies are easy to compare and contrast, and a clear emphasis on diagnostic workup and appropriate treatment is evident.…
Tyler S. · Medical student · review of the book
Questions

Frequently asked questions

What is the founding member offer?

Free now, plus 12 months after launch. The first 500 students who claim a founding spot before launch get every chapter free as it’s released. The free year starts at launch, the day the last chapter goes live. Signing in alone doesn’t claim a spot: sign in with Google, then tap “Claim a founding spot” under Pricing on this page. No card is needed. If you tick “Email me when a new chapter goes live”, we’ll email you as each one is released. After your free year the plan is $25/month.

Does this replace my Qbank?

No. Use your Qbank to practice the exam, and Pradis to work through the confusing distinctions and come back to them.

How does spaced review work?

Every question you answer comes back on a schedule. Answer it correctly at three scheduled reviews (your first answer, 5 days later, about 3 weeks after that, or sooner when your exam is close or you review ahead) and it’s mastered. Miss it, and it comes back tomorrow.

Can I skip the third review if I know the question?

Yes. After two correct spaced answers on different days, choose “I’m confident — skip further reviews”. The item leaves regular reviews and remains eligible for your final check. It is shown as excluded from reviews rather than three-star mastered. You can undo this choice.

What do three stars mean?

You answered correctly at three spaced reviews. Mastered questions still come back now and then, and a later miss marks the question “Needs refresh.”

Will you email me?

A short reminder if reviews pile up while you’re away, plus the occasional progress update. Never more than one a day, and you can turn them off in one click.

Does every question come back before my exam?

The final check revisits questions you have started, weakest first. It cannot guarantee complete coverage: that depends on your exam date and study sessions. Pradis warns you when the remaining check will not fit. Your last 2 days are kept free.

Is it Step 2 CK only?

Yes. Pradis is written for USMLE Step 2 CK and the clinical shelf exams.

Can I try it before I pay?

Yes. Biostatistics is free for everyone, no account needed. Sign in to save your progress.

Who writes the content?

Manoj Gurung, MD and Yayra Musabek, MD, academic hospitalists and the authors of the Thieme A-WIN review book.

Say hello

Get in touch

Send us a question or feedback. We’ll get back to you soon.

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Portions of Pradis are adapted from Thieme Review for the USMLE: A WIN for Step 2 and 3 CK (Thieme, 2021) by Manoj Gurung, MD, and Yayra Musabek, MD, used with permission.

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