Research & Ethics Flashcards
What is evidence-based medicine?
- Clinical judgment
- Best available research/evidence
- Patients’ values and preferences
“use of data from research on populations to inform decisions about individuals”
What is research?
focused systematic inquiry aimed at generating new knowledge
5 A’s of EBM
Ask Acquire Appraise Apply Assess
What type of study is the first step in answering a clinical question?
observational
Reasons to choose an observational study?
Ethical issues, studying a rare disease, not practical or too costly to do an RCT, long time to develop the condition
Descriptive studies
Subtype of observational studies
There is no comparison group and you cannot assess casual associations
Answers who, what, why, when, and where
Three types of observational studies that include a comparison group?
- cross-sectional
- case control
- cohort
What is a cross-sectional study?
A snapshot at one point in time; data on exposure and outcome are collected at the same time period
** cannot assess casual associations
What is a case-control study?
A study where you start with an outcome, find cases with that outcome, and then find controls without that outcome. “Think backwards” and do a retrospective investigation
*** Can measure an odds ratio (OR)
What are the advantages of case-control studies?
Retrospectively identify risk factors, efficient for rare diseases and long latency periods, quick & inexpensive, allows you to look for multiple potential risk factors or exposures
What are the disadvantages of case-control studies?
Selection bias (hard to find true controls), recall bias, interview bias, inability to calculate incidence, relative risk & hazard ratio
What is an odds ratio (OR)?
A comparison of the odds of exposure among cases divided by the odds of exposure among controls
Used as a measure of association for case-control studies
What is a cohort study?
Start with an exposure and then follow over time to look for an outcome to occur or develop
(aka follow-up, incidence, or longitudinal studies)
What are the three types of cohort studies?
- prospective - forward in time from exposure to outcome
- Retrospective - define the outcome and then go back in time to exposure.. then follow foward
- Ambidirectional - prospective and retrospective combined
What are the advantages of cohort studies?
determine incidence, study natural history of disease, efficient for rare exposure & multiple outcomes from single exposure, minimize recall bias, allows calculation of more measures of association
What are the disadvantages of cohort studies?
expensive, time consuming, attrition bias, inefficient for rare disease & long development time, selection bias
What types of intervention may a researcher use in an experimental study?
drug, device, procedure, preventive strategy, or diagnostic study
Why are non-randomized experimental studies performed?
Often to determine feasibility for enrollment or acceptability of interventions
What are the advantages of RCTs?
distribution of variables that might influence the study are randomly distributed (i.e. confounding variables), thus a difference in outcome would be attributed to the treatment/intervention
Non-validated practices
novel or innovative practices that have not been subjected to rigorous study
should be subjected to research in order to validate them before widespread dissemination
What is the goal of clinical practice?
to provide the best care for the individual patient
What is the goal of clinical research?
to produce generalizable knowledge to benefit future patients
Does clinical research use means that are acceptable in clinical practice?
No. Clinical intervention is based on best interests of the patient & patient choice, do not involve placebos, and all parties are aware of the selected intervention
What is a background question?
One that asks for general knowledge about the disorder, test, treatment, etc
What are the two components of a background question?
Root verb + condition
Root + verb = who, what, where, when, why, how + verb
Condition = disease or outcome
Examples: “What causes high blood pressure?,” “Who is at risk for high blood pressure?”
What is a foreground question?
One that asks about specific knowledge to inform clinical decisions and actions
4 main components: PICO
What does PICO stand for?
P = Patient, problem, or population I = Intervention, exposure, prognostic factor or maneuver C = Comparison (if relevant) O = Outcome (including time frame, if relevant)
What are the four main types of foreground questions?
PDT - E
- Prognosis
- Diagnosis
- Therapy
- Etiology/Harm
Therapy questions
Used when we want to find the best treatment (intervention) for a specific disease or condition
(can include preventative treatments)
Diagnosis questions
Used when we want to know how accurate a diagnostic test is in a specific group of patients
Compare new test/procedure to a known gold standard (reference standard)
Prognosis questions
Used when we want to know which factors change the course (prognosis) of a given disease or condition
Estimates progression, likelihood, and complications
Etiology/harm questions
Used when we want to know about negative impact from an exposure or intervention
(public health issues or exposure to environmental agent increases risk of bad outcome)
What type of evidence will help you answer therapy and diagnosis questions?
RCTS and clinical trials
What type of evidence will help you answer prognosis and etiology/harm questions?
Cohort studies
If no cohort then look for case-control… no case-control then cross-sectional, case-series or report
Is it legal for a physician to prescribe an FDA-approved drug for a use other than the non-approved use?
Yes
Can drug, device, and biologic manufacturers market items for unapproved (off-label) uses?
Nope
Unless its in reference texts (full article or as a complete chapter), clinical practice guidelines, or provision of journal articles
What are the four primary phases of FDA testing?
- Safety and dosage
- Safety and effectiveness in small numbers
- Safety and effectiveness with statistical power
- Post-market data collection to assess adverse effects in larger general population
FDA Phase 1
20 to 100 healthy volunteers (unless its testing something like chemo, then affected people) are used to investigate the safe dosage range
About 70% of drugs move on
FDA Phase 2
Up to several hundred people with the disease/condition
About 33% of drugs move on
FDA Phase 3
300 - 3000 affected volunteers are monitored for side effects, effectiveness, and safety
About 25-30% of drugs move on
FDA Phase 4
Post-marketing studies conducted after a treatment is approved for use by the FDA
Conducted in several thousand volunteers with the disease/condition
How long does a patent grant exclusive use?
20 years
What do generic drug competitors have to demonstrate to the FDA?
Bioequivalence to the patented drug
generic releases active ingredient at the same speed and in the same amounts as the original
What variability from the original, patented drug does the FDA require for generics?
5%
Who regulates OTC drug advertising?
FTC
FDA is only Rx drug advertising
The FDA “true statement” advertising requirement is not met if…
advertising is false or misleading, does not present a fair balance, and fails to reveal material facts
What is the adequate provision requirement?
Manufacturers must make “adequate provision” for the consumer to get full labeling information in language they can comprehend
Four sources:
- toll-free phone #
- website
- Referral to concurrent print ad or brochure
- Referral to a healthcare practioner
What is a CONSORT diagram?
A standard way to report RCTs; accounts for what happens to all the subjects from beginning to the end of the trial
Flow diagram from enrollment to study conclusion
What kind of bias does randomization protect against?
Selection bias
Produces a balance comparison between groups if done properly
Simple randomization
Repeated fair coin flip
Permuted block randomization
Randomization is a sequence of blocks. Each block contains a pre-specified number of treatment allocations in random order
At the end of the trial there are equal numbers in each group
Stratified randomization
Achieves balance among groups in terms of subject’s baseline characteristics (covariates)
Ex: stratified by treatment center, age, sex, disease stage
What is allocation concealment?
A method of preventing those enrolling participants from (unconsciously or otherwise) influencing which participants are assigned to a given treatment group
Done before the subject enrolls; always feasible
Why is allocation concealment important?
Inadequate or unclear allocation concealment can lead to overestimating the benefit of the treatment effect
Blinding
Process by which subjects, care-givers, data collectors, outcome adjudicators, etc are unaware of which treatment is given to an individual subject
Done after a subject enrolls; not always feasible
What kind of bias does blinding prevent?
- Ascertainment bias - treating subjects differently based on treatment allocaiton
- Observer bias - data collectors performing subjective assessments
- Recall Bias - during follow-up
Intention-to-treat anaylsis
Statistical concept to address non-adherence & missing outcomes
Provides an unbiased, conservative estimate of treatment effect
Per protocol anaylsis
Excludes those not adherent to treatment, switched groups, missed measurement, violated protocol
Individual clinician equipoise (theoretical equipoise)
If a physician believes one arm of an RCT to be better than another, then it is unethical for that physician to randomize her patient in an RCT. Since her obligation is to recommend what she thinks is in the patient’s best interest.
Community of physicians: clinical equipoise
When the relevant community of physicians (such as a field or specialty) is sufficiently uncertain about which or two or more interventions is best and an RCT will resolve the ambivalence
Absence of evidenced-based validation; indifference or uncertainty