Approaches and Methods in Pharmacology and Toxicology Research Flashcards
While ___________ ________ is concerned with characterization and/or quantification of patterns in nature, ___________ _________ is concerned with a CAUSAL hypothesis advanced to explain one or more patterns uncovered by descriptive science.
Descriptive science; hypothesis testing
Descriptive: people who smoke get cancer
Hypothesis: why does smoking cause cancer?
What is the main issue covered in descriptive science?
a) What are the important observed patterns?
b) Are they more imagined than real?
What is the main issue covered in hypothesis testing?
How likely is it that the hypothesis in question is true?
A _______ _________ makes a prediction about what you should see under the conditions of the study; the study asks whether this prediction is seen.
Causal hypothesis
What is the difference between a hypothesis and a prediction?
A hypothesis: a causal explanation for a given phenomenon/observation/pattern
A prediction: a rigorous, often quantitative, statement, of what will be observed under specific conditions if the hypothesis is true.
If H, then P.
Hypothesis: Consuming greasy high-fat content foods causes more skin oils and breakouts.
Prediction: If the individual consumes greasy foods, then the person will have more skin oils and breakouts.
Descriptive science has an ________ instead of a ________.
Objective; hypothesis
Objective: what do you want to measure/evaluate?
Hypothesis: what’s your best guess?
What is epidemiology?
The scientific study of the patterns, causes, and effects of health and disease conditions in defined populations.
It is the cornerstone of public health. It identifies risk factors for disease and targets for preventive healthcare. It informs policy decisions and evidence-based practice.
It is central to both pharmacology and toxicology.
What are the two types of epidemiological studies?
1) Non-experimental observational studies
2) Experimental/interventional studies
(T/F) Observational studies can be population and individual based. They include lots of opinions and trends but lack a hypothesis.
True!
What are the three different types of observational studies (individual based - analytic)?
Briefly describe each.
1) Cross-sectional study: determine PREVALENCE.
2) Case-control study: compare groups RETROSPECTIVELY to study the DISEASE. they seek to identify possible predictors of outcomes. Eg., they take a group of people with cancer and without and ask about their lives.
3) Cohort study: study the RISK FACTOR (PROSPECTIVE). they measure events in chronological order and can use to distinguish between cause and effect.
What are the two different types of experimental/intervention studies?
Briefly describe each.
1) Randomized Control Trial (RCT): subjects in a population are randomly allocated to different groups (placebo or drug); the results are compared.
2) Non-randomized (Quasi-experimental): subjects in a population are non-randomly allocated to different groups; study population are chosen.
What are the advantages and disadvantages of cross-sectional surveys?
Advantages: Quick, can cover whole population, giving representative information whether people are seeking care or not.
Disadvantages: Based mainly on self report (BIAS?); diagnostic information usually inaccurate; can’t establish causal sequence
What are the advantages and disadvantages of cohort studies?
Advantages: Prospective so it can establish a CAUSAL sequence; can estimate INCIDENCE.
Disadvantages: Time-consuming; costly
What are the advantages and disadvantages of case-control studies?
Advantages: Relatively CHEAP way of focusing on causal factors; stronger than a survey.
Disadvantages: Requires recall of past events (INACCURACY?); controls not equivalent to cases
Which observational study is the strongest? Which one is the weakest?
Strongest: COHORT
Weakest: cross-sectional surveys
What are the advantages and disadvantages of Randomized Control Trial (RCT)?
Advantages: controls for all main forms of bias; good for both etiological and evaluative research
Disadvantages: ethical concerns in etiological applications; often uses selected populations: issue of GENERALIZABILITY?
What are the advantages and disadvantages of Quasi-experiments?
Advantages: May be more practical than RCT: can use “natural experiments”
Disadvantages: Allocation bias often significant
(T/F) Case control studies and cohort studies both prove causation.
False! Only cohort (prospective) can prove causation. Case control studies (retrospective) prove correlation.
What are the four phases of new drug clinical trials?
Phase 1: Checking for safety; first testing in humans (20-100 volunteers)
Phase 2: Checking for efficacy; how well does the drug work? (100-500 patients)
Phase 3: Confirm results; drug MUST be safe + there’s a comparison with current treatment. (1000-5000 patients)
Phase 4: FDA review/phase 4 trials; safety surveillance in real life patients
(T/F) In phase I of cancer treatments, the drug is typically given to cancer patients who’s medications are not working.
True! Healthy volunteers are not used.
How does a parallel clinical trial differ than crossover?
Parallel: RTC - two groups are studied; one gets placebo, the other gets drug.
Crossover: each individual takes both placebo + drug and the results are compared.
In vitro research models involve biochemical experiments and cell-based experiments.
In vivo research models involve rodent models, comparative models and human models.
Which one has the least level of control vs most level of control?
Which one has increasing level of complexity but also increasing weight of evidence?
Least level of control; vivo
Most level of control; vitro
Increasing level of complexity but also increasing weight of evidence; vivo
In vitro (biochem/biophysical) has _______ variability while in vitro (cellular) has ______ variability.
Low; moderate
In vivo model is ____ controlled with ______ complexity and _____ variability. It investigates mechanisms and effects at the _________ level.
less; higher; more
physiological
(T/F) Mathematical modeling approach leads to a PREDICTED biological effect, while a biological approach leads to a MEASURED biological effect.
True!
(T/F) In risk assessment of toxicology, field exposure has increasing ecological relevance and number of influencing factors while laboratory exposure loses relevance.
True!
Risk assessment framework involves:
1) Hazard identification (how much is out there, where is it, is it bioaccessible, determine dose, etc)
2) Effect / Exposure assessment (what is the effect?)
3) Risk characterization (how high is the risk?)
4) Risk management
