Carlos Shared "01 Public Health Sciences (Biostat)" - 7 Picmonics
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.
01 Public Health Sciences (Biostat)
Cross-Sectional Study
- Observational
- (Asks) "What's Happening?"
- Data at One Specific Point in Time
- (Finds) Frequency of Disease
- Measurement
- Prevalence
49 secs
Case Control Study
- Observational
- Retrospective
- Compares those with disease to those without
- (Asks) "What happened?"
- Measurement
- Odds Ratio
47 secs
Cohort Study
- Observational
- Longitudinal
- Studies risk from exposure
- Retrospective
- (Asks) "Who developed disease?"
- Prospective
- (Asks) "Who will develop disease?"
1 min
Twin concordance study
- design
- Compares the frequency with which both monozygotic twins vs both dizygotic twins develop the same disease.
- MEASURES/EXAMPLE
- Measures heritability and influence of environmental factors (“nature vs nurture”).
Adoption study
- DESIGN
- Compares siblings raised by biological vs adoptive parents.
- MEASURES/EXAMPLE
- Measures heritability and influence of environmental factors.
Crossover Study
- In a crossover study, subjects are randomly allocated to a sequence of 2 or more treatments given consecutively.
- The simplest model is the AB/BA type of study in which subjects allocated to the AB study arm receive treatment A followed by treatment B and vice versa in the BA arm.
- Crossover trials allow the patients to serve as their own controls.
- The principal drawback of crossover trials is that the effects of one treatment may "carry over" and alter the response to subsequent treatments. To limit this disadvantage, a washout (no treatment) period is often added between consecutive treatments.
- The washout period is designed to be long enough to allow the effects of prior treatment to wear off.
Clinical Trial Phases
- Experimental study involving humans.
- Compares therapeutic benefits of 2 or more treatments, or of treatment and placebo.
- Study quality improves when study is randomized, controlled, and double-blinded (ie, neither patient nor doctor knows whether the patient is in the treatment or control group)
- Triple-blind refers to the additional blinding of the researchers analyzing the data.
- Four phases (“Does the drug SWIM?”).
- Phase I
- Small number of healthy volunteers or patients with disease of interest.
- “Is it Safe?” Assesses safety, toxicity, pharmacokinetics, and pharmacodynamics.
- Phase II
- Moderate number of patients with disease of interest
- “Does it Work?” Assesses treatment efficacy, optimal dosing, and adverse effects.
- Phase III
- Large number of patients randomly assigned either to the treatment under investigation or to the best available treatment (or placebo).
- “Is it as good or better?” Compares the new treatment to the current standard of care (any Improvement?).
- Phase IV
- Postmarketing surveillance of patients after treatment is approved.
- “Can it stay?” Detects rare or long-term adverse effects. Can result in treatment being withdrawn from Market.
