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Free · No sign-upBiostats, epi, and USPSTF, for free
The topics that cost easy points on USMLE and COMLEX, taught in short interactive videos, then locked in with flashcards, mnemonics, and drills. No account and no payment. Your progress is saved in this browser.
Biostatistics
Screening test math with the 2×2 table
- Building and reading a 2×2 table
- Sensitivity, specificity, PPV, and NPV
- How prevalence changes predictive values
- Cutoffs, ROC curves, and likelihood ratios
5 checkpoints18 cards12 questionsStart the free lessonEpidemiology
Study designs, risk, and bias
- Choosing between cross-sectional, case-control, cohort, and randomized designs
- Relative risk, odds ratio, ARR, RRR, NNT, and NNH
- Incidence vs prevalence
- Lead-time, recall, selection bias, and confounding
5 checkpoints18 cards12 questionsStart the free lessonUSPSTF Guidelines
USPSTF grades and the high-yield screens
- What USPSTF grades A, B, C, D, and I mean
- Breast, cervical, colorectal, and lung cancer screening
- Hypertension, statin, diabetes, and AAA recommendations
- HIV, hepatitis, and STI screening
5 checkpoints19 cards12 questionsStart the free lesson
How each lesson works
Built so you remember it on test day
- Step 1
Watch
A short video that pauses at each key idea and asks you a question before it moves on.
- Step 2
Review
Flashcards with spaced repetition, so each card comes back right before you would forget it.
- Step 3
Remember
A mnemonic for every high-yield list, in the deck and on the page.
- Step 4
Drill
Board-style questions with full explanations and a score breakdown by topic.