Pharmaco-epidemiology Flashcards
Pharmaco-epidemiology
- is the study of use and effect of drugs in a large number of people
- is the application of principles of epidemiology to drug effects and drug use
- comprises of two components: ‘pharmaco’ (meaning drug) and ‘epidemiology’ (meaning the study of distribution and determinants of disease in a population.
-examines the relationship between drug exposure and health outcome in a defined population
Post- marketing surveillance
- refers to the period after drug enters the market
- Adverse Event Reporting Systems
- Assists with pharmacovigilance (i.e., identification, assessment & prevention of adverse drug effects in medication)
- Multiple reports = more pharmaco-epidemiological investigations
- Label changes or even withdrawal from the market
Drug approval process
preclinical
phase 1: Safety
phase 2: efficacy
phase 3: dosing/ population studies
post-marketing
PE through drug development and post-marketing, however most PE studies focus on the period after the drug enters the market
Drug Recalls
Most effective way to protect the public from a defective or potentially harmful product.
Recall can be voluntary (i.e., made by the manufacturing company) or by FDA request.
355 entries on the FDA website from 2017-2022
Drug Recall Classification
class I: a dangerous or defective product that could cause serious health problems or death
class II: a product that might cause a temporary health problem, or pose slight threat of a serious nature.
class iii: a products that is unlikely to cause any adverse health reaction but that violates FDA labelling or manufacturing laws
Clinical trial limitations
- Certain groups like children and pregnant women may be excluded from clinical trials
- Phase 3 clinical trials only have a few 1000’s of people enrolled making it difficult to detect some adverse events that may be rare
- Short duration of clinical trials
Reasons for conducting pharmaco-epidemiology studies
Clinical: hypothesis generating
Regulatory: to obtain approval for marketing and/or as a response to question by regulatory agency
Marketing: if a study illustrates the adverse effects of a drug, it is easier to market.
Legal: to protect from future liabilities regarding the drug.
Association and Causation
- Pharmaco-epidemiology methods are used to evaluate causal relationships between exposure and outcome
- Describing drug use, identifying associations or relationships with drug use and determining causal relationships
- Associations: is there an association between the medication and outcome of interest?
- Causal relationships: did the medication cause the outcome of interest?
Sources of pharmaco-epidemiology data
- spontaneous reporting of adverse events
- global drug surveillance
- prescription event monitoring
- automated databases
Spontaneous reporting of adverse events
New or rare adverse events
- Rare or new AEs may be highlighted that may not have been discovered during clinical trials
Hypothesis generating
- To explore possible explanations for the adverse event in question
Limitation
- No control group to compare
- Factors other than the drug may be contributing to the outcome
Global drug surveillance
Combination of:
-set definitions
- homogenous way to store data
- homogeneous terms to describe AEs
Prescription event monitoring
A cohort of users of a particular drug is defined from their prescriptions and followed up for a predefined period of time, with the purpose of identifying all side effects associated with the drug of interest.
Types of automated databases
Medical record databases
Claims databases
Medical record databases
- Longitudinal, anonymised patient record databases that are used by health care providers for routine patient care
- Wealth of info for research as lifetime’s accumulation of health care information on patients
- growing use to assess un-intended and intended drug effects
Medical record databases Pros and Cons
Pros:
- high validity
- test results
- lifestyle information may be available
Cons:
- sometimes incomplete
- various coding systems
-prescribed information available, not dispensed
