Ace Your First Aid for the USMLE Step 1 (2019) Classes and Exams with Picmonic: #1 Visual Mnemonic Study Tool for Medicine (MD/DO) Students
With Picmonic, facts become pictures. We've taken what the science shows - image mnemonics work - but we've boosted the effectiveness by building and associating memorable characters, interesting audio stories, and built-in quizzing. Whether you're studying for your classes or getting ready for a big exam, we're here to help.
First Aid for the USMLE Step 1 (2019) | Medicine (MD/DO) School Study Aid
Odds Ratio (OR)
- Use
- Case Control Studies
- Measures Association Between an Exposure and an Outcome
- Formula
- Odds of Exposure in Diseased (Sick) Group
- a / c
- Divided /
- Odds of Exposure in Healthy Group
- b / d
- Interpretation
- =1 Exposure does not affect odds
- > 1 Exposure increases disease
- < 1 Exposure decreases disease
2 mins
Relative Risk (RR)
- Use
- Used in Cohort Studies
- Formula
- Risk of Developing Disease
- Equals =
- Exposed Group
- a / (a + b)
- Divided by /
- Unexposed Group
- c / (c + d)
- When Low Prevalence Odds Ratio Approximates Relative Risk
2 mins
Attributable Risk (AR)
- Use
- Proportion Exposure Increases Disease
- Formula
- Incidence of Diseased (Sick)
- Equals =
- Exposed Group
- a / (a + b)
- Minus -
- Unexposed Group
- c / (c + d)
1 min
Quantifying Risk: Contingency 2x2 Table Setup
- Disease
- Along Top (x axis)
- Exposure
- Along Side (y axis)
- A: Exposed and Diseased (Sick)
- B: Exposed and Healthy
- C: Not Exposed and Diseased (Sick)
- D: Not Exposed and Healthy
2 mins
Common Statistical Tests
- Determine If Comparing Numerical Or Categorical Variables
- Numerical Variables
- T-Test For Comparing Means Of Two Groups
- ANOVA For Comparing Means In Greater Than Three Groups
- Comparing Mean Values On Normal/Bell Distribution
- Categorical Variables
- Chi-Squared Test For Comparing Categorical Outcomes In Large Sample Sizes
- Fisher's Exact Test For Comparing Categorical Outcomes In Small Sample Sizes
4 mins
Scientific Bias Types
- DEFINITION
- Bias
- RECRUITING PARTICIPANTS
- Selection Bias
- Berkson Bias
- Attrition Bias
- PERFORMING STUDY
- Recall Bias
- Measurement Bias
- Procedure Bias
- Observer-expectancy Bias
- INTERPRETING RESULTS
- Confounding Bias
- Lead-time Bias
- Length-time Bias
6 mins
